CLDN2

Summary

CLDN2 (claudin 2, HGNC:2041) is a protein-coding gene on chromosome Xq22.3, encoding Claudin-2 (P57739). Forms paracellular channels: polymerizes in tight junction strands with cation- and water-selective channels through the strands, conveying epithelial permeability in a process known as paracellular tight junction permeability.

This gene product belongs to the claudin protein family whose members have been identified as major integral membrane proteins localized exclusively at tight junctions. Claudins are expressed in an organ-specific manner and regulate tissue-specific physiologic properties of tight junctions. This protein is expressed in the intestine. Alternatively spliced transcript variants with different 5’ untranslated region have been found for this gene.

Source: NCBI Gene 9075 — RefSeq curated summary.

At a glance

• Gene–disease (curated): hereditary chronic pancreatitis (Limited, GenCC) — +1 more curated relationship
• GWAS associations: 3
• Clinical variants (ClinVar): 73 total — 1 pathogenic, 1 likely-pathogenic
• GTEx eGene: eQTL in 5 tissues, sQTL in 0 (q < 0.05)
• Phenotypes (HPO): 5
• MANE Select transcript: NM_020384
• Notable: 73 clinical variants but no curated precision-oncology (CIViC) evidence yet

Identifiers

Gene identifiers

Field	Value
HGNC ID	HGNC:2041
Approved symbol	CLDN2
Name	claudin 2
Location	Xq22.3
Locus type	gene with protein product
Status	Approved
Ensembl gene	ENSG00000165376
Ensembl biotype	protein_coding
OMIM	300520
Entrez	9075

Gene structure

Transcript identifiers

Ensembl transcripts: 9 — 9 protein_coding

MANE Select: ENST00000336803

Transcript support level (Ensembl TSL; 1 = fully mRNA-supported): TSL 1: 2, TSL 2: 1

ENST00000336803, ENST00000540876, ENST00000541806, ENST00000899662, ENST00000899663, ENST00000899664, ENST00000899665, ENST00001116670, ENST00001136675

RefSeq mRNA: 3 — MANE Select: NM_020384 NM_001171092, NM_001171095, NM_020384

CCDS: CCDS14524

Canonical transcript exons

ENST00000336803 — 2 exons

Exon	Start	End
ENSE00001294483	106920402	106920551
ENSE00001362423	106928051	106930861

Expression profiles

Bgee: expression breadth ubiquitous, 125 present calls, max score 99.45.

FANTOM5 (CAGE): breadth tissue_specific, TPM avg 1.2046 / max 265.1168, expressed in 83 samples.

Highest expression (Bgee): kidney epithelium, pancreatic ductal cell, gall bladder, islet of Langerhans, adult mammalian kidney.

Genetic regulation across tissues (GTEx eQTL / sQTL)

CLDN2 is an eGene in GTEx v10 — its expression is genetically regulated (eQTL) in 5 tissues and its splicing (sQTL) in 0 (q < 0.05). Strongest associations first; slope = normalized effect of the lead variant’s alternative allele.

5 significant tissue × QTL associations:

Tissue	QTL	q-value	Slope	Lead variant
Pancreas	eqtl	2.4e-24	+0.46	X:106901299:T:C
Thyroid	eqtl	9.2e-06	-0.21	X:107001537:C:T
Cells Cultured fibroblasts	eqtl	5.4e-03	-0.75	X:106659507:CTAAG:C
Esophagus Muscularis	eqtl	1.2e-02	+0.51	X:107770114:C:T
Pituitary	eqtl	4.3e-02	-0.66	X:107654479:G:C

FANTOM5 promoters

3 alternative TSS:

Promoter ID	TPM avg	Samples expressed
197172	0.9761	55
197171	0.1192	26
197170	0.1094	27

Top tissues by expression

showing 100 of 237 tissues by Bgee expression score (0-100, higher = more expressed):

Tissue	Anatomy ID	Expression score	Quality
kidney epithelium	UBERON:0004819	99.45	gold quality
pancreatic ductal cell	CL:0002079	98.23	silver quality
gall bladder	UBERON:0002110	98.18	gold quality
islet of Langerhans	UBERON:0000006	92.36	gold quality
adult mammalian kidney	UBERON:0000082	92.34	gold quality
right lobe of liver	UBERON:0001114	89.61	gold quality
kidney	UBERON:0002113	88.70	gold quality
adult organism	UBERON:0007023	87.94	gold quality
liver	UBERON:0002107	85.56	gold quality
seminal vesicle	UBERON:0000998	84.44	gold quality
cortex of kidney	UBERON:0001225	84.40	gold quality
ileal mucosa	UBERON:0000331	83.16	silver quality
renal medulla	UBERON:0000362	81.72	gold quality
duodenum	UBERON:0002114	80.01	gold quality
small intestine Peyer’s patch	UBERON:0003454	79.96	gold quality
caput epididymis	UBERON:0004358	79.76	gold quality
small intestine	UBERON:0002108	78.65	gold quality
pancreas	UBERON:0001264	77.94	gold quality
metanephros cortex	UBERON:0010533	77.14	gold quality
buccal mucosa cell	CL:0002336	76.33	silver quality
body of pancreas	UBERON:0001150	71.45	gold quality
metanephros	UBERON:0000081	70.38	gold quality
pylorus	UBERON:0001166	68.75	gold quality
corpus epididymis	UBERON:0004359	67.65	gold quality
right adrenal gland cortex	UBERON:0035827	66.04	gold quality
left adrenal gland	UBERON:0001234	65.99	gold quality
vermiform appendix	UBERON:0001154	65.61	gold quality
right adrenal gland	UBERON:0001233	65.42	gold quality
adrenal cortex	UBERON:0001235	64.86	gold quality
left adrenal gland cortex	UBERON:0035825	64.84	gold quality
jejunal mucosa	UBERON:0000399	64.07	gold quality
cerebellar vermis	UBERON:0004720	64.01	gold quality
adrenal gland	UBERON:0002369	63.06	gold quality
tibialis anterior	UBERON:0001385	62.97	silver quality
rectum	UBERON:0001052	62.10	gold quality
caecum	UBERON:0001153	60.10	gold quality
sperm	CL:0000019	59.19	gold quality
mucosa of transverse colon	UBERON:0004991	58.19	gold quality
jejunum	UBERON:0002115	56.79	gold quality
upper leg skin	UBERON:0004262	56.21	silver quality
colonic epithelium	UBERON:0000397	56.11	silver quality
upper arm skin	UBERON:0004263	55.75	gold quality
deltoid	UBERON:0001476	54.58	gold quality
cardiac muscle of right atrium	UBERON:0003379	54.34	gold quality
left ventricle myocardium	UBERON:0006566	54.23	gold quality
oocyte	CL:0000023	52.82	gold quality
intestine	UBERON:0000160	52.59	gold quality
pigmented layer of retina	UBERON:0001782	52.55	silver quality
body of stomach	UBERON:0001161	52.10	gold quality
stomach	UBERON:0000945	51.80	gold quality
mucosa of stomach	UBERON:0001199	51.16	gold quality
skin of hip	UBERON:0001554	51.10	silver quality
myocardium	UBERON:0002349	50.25	gold quality
quadriceps femoris	UBERON:0001377	49.73	gold quality
bone marrow cell	CL:0002092	49.68	gold quality
muscle tissue	UBERON:0002385	49.30	gold quality
cauda epididymis	UBERON:0004360	49.29	gold quality
stromal cell of endometrium	CL:0002255	48.93	gold quality
omental fat pad	UBERON:0010414	48.79	gold quality
peritoneum	UBERON:0002358	48.77	gold quality
visceral pleura	UBERON:0002401	48.65	silver quality
ventricular zone	UBERON:0003053	48.52	gold quality
thymus	UBERON:0002370	48.51	gold quality
smooth muscle tissue	UBERON:0001135	48.38	gold quality
adipose tissue of abdominal region	UBERON:0007808	48.34	gold quality
lateral globus pallidus	UBERON:0002476	47.32	gold quality
hindlimb stylopod muscle	UBERON:0004252	47.26	silver quality
corpus callosum	UBERON:0002336	47.22	gold quality
nasal cavity epithelium	UBERON:0005384	47.03	gold quality
olfactory segment of nasal mucosa	UBERON:0005386	46.94	gold quality
subcutaneous adipose tissue	UBERON:0002190	46.68	gold quality
adipose tissue	UBERON:0001013	46.55	gold quality
skin of abdomen	UBERON:0001416	46.26	gold quality
skin of leg	UBERON:0001511	45.95	gold quality
vastus lateralis	UBERON:0001379	45.87	gold quality
lateral nuclear group of thalamus	UBERON:0002736	45.61	gold quality
subthalamic nucleus	UBERON:0001906	45.57	gold quality
zone of skin	UBERON:0000014	45.56	gold quality
layer of synovial tissue	UBERON:0007616	45.43	gold quality
dorsal plus ventral thalamus	UBERON:0001897	45.42	silver quality
substantia nigra pars reticulata	UBERON:0001966	45.25	gold quality
nasal cavity mucosa	UBERON:0001826	44.89	silver quality
tonsil	UBERON:0002372	44.85	gold quality
trigeminal ganglion	UBERON:0001675	44.44	gold quality
middle temporal gyrus	UBERON:0002771	44.42	gold quality
fallopian tube	UBERON:0003889	44.38	gold quality
cardia of stomach	UBERON:0001162	44.27	gold quality
placenta	UBERON:0001987	44.21	silver quality
muscle of leg	UBERON:0001383	44.01	silver quality
amniotic fluid	UBERON:0000173	43.96	gold quality
bone marrow	UBERON:0002371	43.82	gold quality
dorsal root ganglion	UBERON:0000044	43.80	gold quality
fundus of stomach	UBERON:0001160	43.61	gold quality
descending thoracic aorta	UBERON:0002345	43.43	gold quality
lung	UBERON:0002048	43.37	gold quality
skeletal muscle tissue of rectus abdominis	UBERON:0004511	43.37	gold quality
cortical plate	UBERON:0005343	43.34	gold quality
large intestine	UBERON:0000059	43.31	gold quality
globus pallidus	UBERON:0001875	43.16	gold quality
colon	UBERON:0001155	43.06	gold quality

Single-cell (SCXA)

Detected in 3 experiment(s), a significant marker in 3.

Experiment	Marker?	Max mean expression
E-GEOD-83139	yes	1080.82
E-MTAB-8495	yes	830.81
E-ANND-3	yes	3.71

HPA expression

RNA tissue specificity: Tissue enhanced

showing 60 of 61 HPA tissues / cells by nTPM:

Tissue / cell	Axis	nTPM	Protein (IHC)
Choroid plexus	tissue	243.0
Kidney	tissue	154.2	medium
Gallbladder	tissue	95.3	high
Seminal vesicle	tissue	85.1	low
Liver	tissue	39.5	not detected
Epididymis	tissue	31.8	not detected
Small intestine	tissue	23.0	low
Duodenum	tissue	19.7	low
Stomach 1	tissue	7.3	low
Superior colliculi	tissue	4.4
Rectum	tissue	4.3	not detected
Adrenal gland	tissue	2.8
Medulla oblongata	tissue	2.6
Caudate putamen	tissue	2.3
Appendix	tissue	2.0	not detected
Colon	tissue	1.9	not detected
Thalamus	tissue	1.6
Substantia nigra	tissue	1.3
Lung	tissue	1.3	not detected
Cerebellum	tissue	1.1	not detected
Pancreas	tissue	1.0	not detected
Basal ganglia	tissue	1.0	not detected
Amygdala	tissue	1.0
Periaqueductal gray	tissue	1.0
Midbrain	tissue	0.9
Hippocampal formation	tissue	0.9
Olfactory bulb	tissue	0.9
Hippocampus	tissue	0.8	not detected
Corpus callosum	tissue	0.8
Ventral forebrain	tissue	0.8
Cerebral cortex	tissue	0.7	not detected
Retina	tissue	0.7
Nucleus accumbens	tissue	0.7
Hypothalamus	tissue	0.7
Postcentral gyrus	tissue	0.7
Septum	tissue	0.7
Retrosplenial cortex	tissue	0.7
Temporal cortex	tissue	0.7
Insular cortex	tissue	0.7
Breast	tissue	0.6
Prefrontal cortex	tissue	0.6
Pons	tissue	0.6
Adipose tissue	tissue	0.6	not detected
Putamen	tissue	0.6
Locus coeruleus	tissue	0.6
Entorhinal cortex	tissue	0.6
Retrosplenial and cingulate cortex	tissue	0.6
Occipital cortex	tissue	0.6
Motor cortex	tissue	0.5
Thyroid gland	tissue	0.5	not detected
Spinal cord	tissue	0.5
Somatosensory cortex	tissue	0.5
Skin 1	tissue	0.3	not detected
Pituitary gland	tissue	0.2
Skeletal muscle	tissue	0.2	not detected
Fallopian tube	tissue	0.2	not detected
Esophagus	tissue	0.1
Smooth muscle	tissue	0.1	not detected
Endometrium 1	tissue	0.1	not detected
Frontal cortex	tissue	0.1

Brain sub-regions (HPA Brain Atlas): detected in 190; highest nTPM — Hippocampus, CA3 (18.1), Vermis (3.8), Habenula (3.3), Hippocampus, CA2 (2.8), Medial dorsal thalamic nucleus (2.0).

Regulation

Is transcription factor: no

Upstream regulators (CollecTRI, top): AP1, CDX1, CDX2, CLDN5, CTNNB1, GATA4, GLI1, HNF1A, HNF4A, JUN, LEF1, OCLN, PPARG, TCF4

miRNA regulators (miRDB)

Targeting CLDN2 by miRDB confidence (max_score; target_count = how many genes the miRNA targets in total — lower means more specific).

showing 30 of 97 miRNAs:

miRNA	Max score	Avg score	miRNA target_count
HSA-MIR-8485	100.00	77.57	4731
HSA-MIR-4481	100.00	66.42	1669
HSA-MIR-3689D	100.00	66.14	1181
HSA-MIR-6851-5P	100.00	65.63	1294
HSA-MIR-6870-5P	99.99	68.55	2115
HSA-MIR-4534	99.99	66.58	1907
HSA-MIR-4723-5P	99.97	68.70	2034
HSA-MIR-5698	99.97	68.49	2029
HSA-MIR-7111-5P	99.97	68.48	2062
HSA-MIR-8082	99.95	67.27	1170
HSA-MIR-4525	99.94	64.38	675
HSA-MIR-5010-5P	99.94	64.11	705
HSA-MIR-651-3P	99.94	73.48	5177
HSA-MIR-335-3P	99.93	73.36	4958
HSA-MIR-497-5P	99.92	71.83	2674
HSA-MIR-515-5P	99.92	69.82	2343
HSA-MIR-519E-5P	99.92	69.62	2358
HSA-MIR-338-5P	99.92	72.34	2951
HSA-MIR-205-3P	99.92	69.92	3165
HSA-MIR-15A-5P	99.90	72.80	2787
HSA-MIR-15B-5P	99.90	72.78	2798
HSA-MIR-16-5P	99.90	72.80	2780
HSA-MIR-195-5P	99.90	72.81	2805
HSA-MIR-153-5P	99.89	73.86	6317
HSA-MIR-424-5P	99.89	71.90	2641
HSA-MIR-6838-5P	99.89	71.94	2690
HSA-MIR-6783-3P	99.89	67.92	2059
HSA-MIR-3065-3P	99.87	70.25	1407
HSA-MIR-6857-5P	99.87	65.32	985
HSA-MIR-8073	99.86	65.21	1118

Functional genomics

Regional missense constraint (gnomAD)

ENST00000336803 splits into 2 regions with different missense tolerance; 0 are missense-constrained. Missense variants in a constrained region (low observed/expected) are more likely to be pathogenic. gnomAD

Region (GRCh38)	Missense obs / exp	o/e	Constrained
X:106,928,229–106,928,513	27 / 72.2	0.37	no
X:106,928,514–106,928,918	81 / 100.8	0.80	no

Literature-anchored findings (GeneRIF, showing 40)

• identification of eIF4AIII and Barentsz as components of a conserved protein complex that is essential for mRNA localization in flies and nonsense-mediated mRNA decay in mammals (PMID:14973490)
• dIF4A is a maternal-effect suppressor of decapentalplegic. (PMID:15972466)
• eIF4A has a novel function as a specific inhibitor of Dpp signalling that mediates the degradation of SMAD homologues. (PMID:17115029)
• The results suggest that the eIF4A gene is under the control of the DREF pathway and DREF is therefore involved in the regulation of protein synthesis. (PMID:17888422)
• eIF4A controls germline stem cell self-renewal by directly inhibiting BAM function in the Drosophila ovary. (PMID:19556547)
• our data identify the eIF4F complex as an important upstream regulator of TORC1, which acts via TSC2 to inactivate TORC1 upon withdrawal of amino acids (PMID:26988032)
• Rare EIF4A2 variants are associated with a neurodevelopmental disorder characterized by intellectual disability, hypotonia, and epilepsy. (PMID:36528028)
• Cloning of the human claudin-2 5’-flanking region revealed a TATA-less promoter with conserved binding sites in mouse and human for caudal-related homeodomain proteins and hepatocyte nuclear factor-1alpha. (PMID:11934881)
• Results support a model in which claudins 2 and 4 create paracellular channels and the first extracellular domain is sufficient to determine both paracellular charge selectivity and transepithelial electrical resistance. (PMID:12700140)
• role for the paracellular barrier function by opening pores for small cations (PMID:14751232)
• optimal claudin-2 expression in the gut relies on the presence of GATA-4, suggesting a role for this factor in intestinal regionalization (PMID:15389642)
• No obvious correlation was found between claudin-2 expression and clinicopathological parameters of colorectal cancers. (PMID:16328347)
• Claudin tight junction proteins in endoscopy biopsy samples showed Barrett’s metaplasia contains more claudin-2 and claudin-3 than found in normal esophageal mucosa, but markedly lower claudins 1 and 5, indicating very different tight junction barriers. (PMID:17103306)
• Expression of claudin-2 was increased in acute calculous cholecystitis. (PMID:17283368)
• RT-PCR data show high expression of putative tumor suppressor genes Rsk4 and RbAp46 in 47% and 79% of breast carcinoma cases, respectively, whereas Cldn2 was down-regulated in 52% of breast cancer cases compared with normal adjacent tissues. (PMID:17314274)
• Comparison of adenocarcinomas and squamous cell carcinomas revealed significant differences in CLDN2 expression. (PMID:17418912)
• IL-4 and interferon gamma have opposite effects on the expression of claudin-2 and the physiology of the tight junction (PMID:17640674)
• The expression of claudin-1 and claudin-2 in cancer tissues was upregulated 40- and 49.2-fold, respectively, at the mRNA level, as compared with that in normal tissues (PMID:17970035)
• Expression of claudin-2 results in a selective increase in pore number but not size and has no effect on the permeability of PEGs that are larger than the pores. (PMID:18198187)
• These findings strongly suggest that claudin-2- and/or claudin-12-based tight junctions form paracellular Ca(2+) channels in intestinal epithelia, and they highlight a novel mechanism behind vitamin D-dependent calcium homeostasis. (PMID:18287530)
• Claudin-2 protein overexpression may be closely correlated to gastric carcinogenesis. (PMID:18366005)
• Significant correlations sre found between claudin-2 and Cdx2 protein expression in dysplasia and intestine-type adenocarcinoma. (PMID:18500171)
• The discovery of claudin 2 transcript and protein in the skin could be of importance in epidermal differentiation, barrier function and pathological conditions. (PMID:18509255)
• These results provide an insight into the changes in the inter-molecular forces and adhesion kinetics of Cldn2 mediated interactions in acidic, neutral and alkaline environments. (PMID:18602630)
• Claudin-1 and claudin-2 expression was elevated in active inflammatory bowel disease (IBD), adenomas, and IBD-associated dysplasia, but not acute self limiting colitis (PMID:18711353)
• findings are consistent with the hypothesis that EGFR signaling plays an important role in A549 cell physiology and acts synergistically with claudin-2 to accelerate tumor colonizati (PMID:18942115)
• The expression of claudins-2, -3 and -4 in 16 rectal well-differentiated endocrine neoplasms was studied (PMID:19082451)
• Up-regulation of claudin-2 might lead to altered tight junction structure and be related to the impaired epithelial function in active ulcerative colitis. (PMID:19120888)
• The up-regulation of claudin-2 by TNFalpha is attributable to the regulation of the expression of the gene, as a result of which epithelial barrier function is disturbed. (PMID:19214581)
• Data show that claudin-2 expression was reduced following symplekin down-regulation, and siRNA-mediated claudin-2 down-regulation increased the transepithelial resistance and decreased cyclin D1 expression and ZONAB nuclear localization. (PMID:20133805)
• CLDN 2 expression was significantly increased in severe form of coeliac disease in bulb and in distal duodenum (PMID:20143085)
• claudin-2 was not expressed in any of the 18 cases of Epstein-Barr virus-associated nasopharyngeal carcinoma studied. (PMID:20204275)
• The authors propose claudin-2 and SYN1 work in concert to enhance microbial translocation across the intestinal epithelial barrier to contribute to chronic immune activation and CD4 T-cell depletion in HIV-1-infected patients. (PMID:20700059)
• CLDN2 is selectively enriched in and promotes the formation of breast cancer liver metastases through engagement of cell membrane complexes. (PMID:21076473)
• demonstrate here that breast cancer cells harbouring PIK3CA mutations are selectively sensitive to mTOR allosteric and kinase inhibitors. However, cells with PTEN loss of function are not sensitive to these drugs (PMID:21383692)
• Pore-forming tight junction protein claudin-2 is strongly expressed in the ileum of 51% patients in quiescent phase and in 49% of the patients with active Crohn’s disease. (PMID:21688348)
• These results suggest that EGF is secreted from A549 cells by MMP and increases claudin-2 expression mediated via the activation of an EGFR/MEK/ERK pathway. (PMID:22546605)
• Stable expression of inducible GFP-SUMO-1 in MDCK cells resulted in decreased levels of claudin-2 protein by immunoblot and decreased claudin-2 membrane expression (PMID:22731716)
• Sinonasal epithelium in allergic fungal rhinosinusitis displays increased epithelial permeability and an altered expression of claudin-2 (PMID:22927233)
• results implicate pericryptal myofibroblast-derived paracrine KGF and largely autocrine amphiregulin in the upregulation of claudin-2 in Caco-2 epithelial monolayers and consequent disruption of tight junction integrity (PMID:22946653)

Cross-species orthologs

3 orthologs

Organism	Symbol	Gene ID
danio_rerio	cldn2	ENSDARG00000044387
mus_musculus	Cldn2	ENSMUSG00000047230
rattus_norvegicus	Cldn2	ENSRNOG00000054495

Paralogs (22): CLDN11 (ENSG00000013297), CLDN18 (ENSG00000066405), CLDN15 (ENSG00000106404), CLDN16 (ENSG00000113946), CLDN10 (ENSG00000134873), CLDN17 (ENSG00000156282), CLDN8 (ENSG00000156284), CLDN14 (ENSG00000159261), CLDN1 (ENSG00000163347), CLDN19 (ENSG00000164007), CLDN3 (ENSG00000165215), CLDN20 (ENSG00000171217), CLDN22 (ENSG00000177300), CLDN7 (ENSG00000181885), CLDN5 (ENSG00000184113), CLDN6 (ENSG00000184697), CLDN24 (ENSG00000185758), CLDN4 (ENSG00000189143), CLDN9 (ENSG00000213937), CLDN25 (ENSG00000228607), CLDN34 (ENSG00000234469), CLDN23 (ENSG00000253958)

Mouse-model phenotypes

Observed phenotypes of the mouse ortholog (MGI:1276110) from MGI (Alliance of Genome Resources) — knockout/mutant phenotypes, ranked by annotation count. 14 distinct phenotype terms.

Mouse phenotype (MP)	Records
increased urine sodium level	2
abnormal renal sodium reabsorption	2
polyuria	1
decreased urine osmolality	1
increased susceptibility to kidney reperfusion injury	1
hypoxia	1
increased oxygen consumption	1
increased urine calcium level	1
increased circulating creatinine level	1
increased blood urea nitrogen level	1
abnormal renal reabsorption	1
abnormal renal water reabsorption	1
abnormal renal sodium ion transport	1
decreased kidney enzyme/coenzyme level	1

Additional cross-species homologs

Sequence homologs in species beyond Ensembl Compara’s model organisms, by Diamond local protein alignment (% sequence identity; best hit per species). Lower-identity rows are more distant homologs. The matched accessions’ gene symbols aren’t in biobtree yet, so each row shows the UniProt accession.

Organism	UniProt	Identity	Method
Chlorocebus aethiops	O19005	99.0%	Diamond
Bos taurus	Q2HJ22	95.9%	Diamond
Canis lupus familiaris	Q95KM5	94.5%	Diamond
Sus scrofa	C3VMW3	85.8%	Diamond

Genomic neighbors (locus context)

Genes flanking this one on the chromosome (NCBI/Entrez gene neighborhood). Positional context only — some neighbors share regulatory elements (bidirectional promoters, antisense/overlapping transcripts), but chromosomal adjacency is not itself a functional relationship (see Interactions for that).

Symbol	Type	Entrez
NUP62CL	protein-coding	54830
RBM41	protein-coding	55285
MORC4	protein-coding	79710
RIPPLY1	protein-coding	92129
TBC1D8B	protein-coding	54885
MIR548AN	ncRNA	100616144
RADX	protein-coding	55086
RNF128	protein-coding	79589

Protein

Protein identifiers

Claudin-2 — P57739 (reviewed: P57739)

Alternative names: SP82

All UniProt accessions (1): P57739

UniProt curated annotations — full annotation on UniProt →

Function. Forms paracellular channels: polymerizes in tight junction strands with cation- and water-selective channels through the strands, conveying epithelial permeability in a process known as paracellular tight junction permeability. In intestinal epithelium, allows for sodium and water fluxes from the peritoneal side to the lumen of the intestine to regulate nutrient absorption and clear enteric pathogens as part of mucosal immune response. In kidney, allows passive sodium and calcium reabsorption across proximal tubules from the lumen back to the bloodstream. In the hepatobiliary tract, allows paracellular water and cation fluxes in the hepatic perivenous areas and biliary epithelium to generate bile flow and maintain osmotic gradients.

Subunit / interactions. Can form homo- and heteropolymers with other claudins to mediate paracellular barrier and channel functions of tight junctions in response to physiological stimuli. Homopolymers interact with CLDN3, but not CLDN1, homopolymers. Directly interacts with TJP1/ZO-1, TJP2/ZO-2 and TJP3/ZO-3.

Subcellular location. Cell junction. Tight junction. Cell membrane.

Post-translational modifications. The disulfide bond is necessary for pore formation, but is not required for correct protein trafficking.

Disease relevance. Azoospermia, obstructive, with nephrolithiasis (OAZON) [MIM:301060] An X-linked recessive, male infertility disorder characterized by epidydimal obstruction, hypercalciuria and kidney stones. The disease may be caused by variants affecting the gene represented in this entry.

Similarity. Belongs to the claudin family.

RefSeq proteins (3): NP_001164563, NP_001164566, NP_065117* (*=MANE)

Domains & families (InterPro)

ID	Name	Type
IPR004031	PMP22/EMP/MP20/Claudin	Family
IPR005411	Claudin2	Family
IPR006187	Claudin	Family
IPR017974	Claudin_CS	Conserved_site

Pfam: PF00822

Catalyzed reactions (Rhea)

• K(+)(in) = K(+)(out) (RHEA:29463)
• H2O(in) = H2O(out) (RHEA:29667)
• Ca(2+)(in) = Ca(2+)(out) (RHEA:29671)
• choline(out) = choline(in) (RHEA:32751)
• Na(+)(in) = Na(+)(out) (RHEA:34963)
• methylamine(out) = methylamine(in) (RHEA:74391)
• Rb(+)(in) = Rb(+)(out) (RHEA:78547)
• Li(+)(in) = Li(+)(out) (RHEA:78551)
• Cs(+)(in) = Cs(+)(out) (RHEA:78555)

UniProt features (21 total): topological domain 5, transmembrane region 4, region of interest 2, modified residue 2, chain 1, compositionally biased region 1, site 1, disulfide bond 1, cross-link 1, sequence variant 1, helix 1, strand 1

Structure

Experimental structures (PDB)

1 structures by resolution:

PDB	Title	Method	Resolution (Å)
4YYX	Crystal structure of the ZO-1 PDZ1 domain in complex with the 7-mer Claudin2 C-terminal …	X-RAY DIFFRACTION	1.79

Predicted structure (AlphaFold)

Model	pLDDT	Fraction very-high
AF-P57739-F1	78.99	0.42

Human Protein Atlas

Protein class: Predicted membrane proteins, Disease related genes

Protein evidence: Evidence at protein level

Subcellular location (HPA, imaging): cell junctions; plasma membrane; nucleoli; nucleoplasm; vesicles

Antibody reliability (HPA): IH enhanced · IF supported

Functional residue map

Curated UniProt residues grouped by drug-discovery relevance — catalytic, ligand-binding, modification, and mutation-validated positions. Source: UniProtKB sequence features.

Catalytic / active sites (1)

Position	Role
65	paracellular cation selectivity

Post-translational modifications (3)

Type	Positions
Phosphoserine	219, 223
Glycyl lysine isopeptide (lys-gly) (interchain with g-cter in sumo)	218

Disulfide bonds (1)

Type	Positions
Disulfide bond	54–64

Function

Pathways and Gene Ontology

Reactome pathways

0 curated (TAS) of 4; 0 disease pathways. Curated-first; evidence = TAS (manually curated) vs IEA (electronic inference).

4 pathways:

ID	Pathway	Evidence
R-HSA-446728	Cell junction organization	—
R-HSA-1500931	Cell-Cell communication	—
R-HSA-421270	Cell-cell junction organization	—
R-HSA-420029	Tight junction interactions	electronic

MSigDB gene sets: 143 (showing top): GOBP_DIGESTION, GOBP_ACID_SECRETION, HNF3ALPHA_Q6, GOBP_REGULATION_OF_ORGANIC_ACID_TRANSPORT, TGCTGCT_MIR15A_MIR16_MIR15B_MIR195_MIR424_MIR497, XU_GH1_AUTOCRINE_TARGETS_UP, ACEVEDO_NORMAL_TISSUE_ADJACENT_TO_LIVER_TUMOR_DN, KEGG_TIGHT_JUNCTION, FOXO1_01, CAGCTG_AP4_Q5, GOBP_ORGAN_OR_TISSUE_SPECIFIC_IMMUNE_RESPONSE, RODRIGUES_NTN1_TARGETS_DN, GOBP_ORGANIC_ACID_TRANSPORT, GOBP_CELL_CELL_ADHESION, GOBP_DEFENSE_RESPONSE_TO_OTHER_ORGANISM

GO Biological Process (7): innate immune response in mucosa (GO:0002227), calcium-independent cell-cell adhesion (GO:0016338), cell-cell adhesion (GO:0098609), regulation of bile acid secretion (GO:0120188), paracellular transport (GO:0160184), regulation of intestinal D-glucose absorption (GO:1903985), regulation of intestinal lipid absorption (GO:1904729)

GO Molecular Function (4): structural molecule activity (GO:0005198), identical protein binding (GO:0042802), paracellular tight junction channel activity (GO:0160187), protein binding (GO:0005515)

GO Cellular Component (6): plasma membrane (GO:0005886), cell-cell junction (GO:0005911), bicellular tight junction (GO:0005923), cell junction (GO:0030054), tight junction (GO:0070160), membrane (GO:0016020)

Reactome top-level categories

3 top-level categories:

Category	Pathways
Cell-cell junction organization	1
Cell junction organization	1
Cell-Cell communication	1

GO top-level categories

22 GO namespaces:

Category	Terms
regulation of intestinal absorption	2
cellular anatomical structure	2
mucosal immune response	1
innate immune response	1
cell-cell adhesion	1
cell adhesion	1
bile acid secretion	1
regulation of organic acid transport	1
regulation of secretion	1
transport	1
intestinal D-glucose absorption	1
intestinal lipid absorption	1
molecular_function	1
protein binding	1
transporter activity	1
binding	1
membrane	1
cell periphery	1
anchoring junction	1
apical junction complex	1
tight junction	1
cell-cell junction	1

Experimentally-supported GO annotations

GO terms backed by direct experimental evidence (ECO experimental codes) — 7 of 17 annotations. The rest are phylogenetic / computational / electronic (IEA).

7 experimentally-supported GO terms:

GO term	NS	Evidence
paracellular transport	BP	direct assay
cell junction	CC	direct assay
cell-cell junction	CC	direct assay
plasma membrane	CC	direct assay
tight junction	CC	direct assay
identical protein binding	MF	direct assay
paracellular tight junction channel activity	MF	direct assay

Protein interactions and networks

STRING

showing 15 of 908 interactions by confidence (×1000):

Protein A	Protein B	Partner UniProt	Score
CLDN2	OCLN	Q16625	928
CLDN2	TJP1	Q07157	894
CLDN2	CLDN12	P56749	893
CLDN2	HSP90AB1	P08238	856
CLDN2	HSP90AA1	P07900	803
CLDN2	TJP2	Q9UDY2	716
CLDN2	CDC37	Q16543	691
CLDN2	IL6	P05231	681
CLDN2	IL13	P35225	679
CLDN2	MARVELD2	Q8N4S9	676
CLDN2	CDK4	P11802	664
CLDN2	F11R	Q9Y624	654
CLDN2	EIF2AK4	Q9P2K8	650
CLDN2	TJP3	O95049	622
CLDN2	CDX1	P47902	612

IntAct

Human interaction partners of CLDN2 in IntAct, one row per partner (best MIscore; records = supporting IntAct interaction records).

showing 30 of 99 partners by confidence:

Partner	Interaction type	MIscore	Records
ADAM33	physical association	0.560	3
BTN3A2	physical association	0.560	3
CLEC2D	physical association	0.560	3
CSGALNACT2	physical association	0.560	3
CXCL9	physical association	0.560	3
CYSRT1	physical association	0.560	3
EMP3	physical association	0.560	3
FAM209A	physical association	0.560	3
GRM2	physical association	0.560	3
IGFBP5	physical association	0.560	3
IL27RA	physical association	0.560	3
KRT31	physical association	0.560	3
KRTAP1-1	physical association	0.560	3
KRTAP1-3	physical association	0.560	3
LAT	physical association	0.560	3
LPAR3	physical association	0.560	3
NOTCH2NLA	physical association	0.560	3
PLP1	physical association	0.560	3
TEX264	physical association	0.560	3
TMEM218	physical association	0.560	3
TJP1	colocalization	0.550	2
SQSTM1	colocalization	0.540	4
AP2M1	association	0.540	3
PATJ	direct interaction	0.440	7
GRIP1	direct interaction	0.440	5
GRIP2	direct interaction	0.440	5
DLG3	direct interaction	0.440	3
LNX1	direct interaction	0.440	3
MPDZ	direct interaction	0.440	3
PDZK1	direct interaction	0.440	3

BioGRID (32 interactions; top human partners by supporting records): SQSTM1 (Affinity Capture-Western; 3 records), ADAM33 (Two-hybrid), BTN3A2 (Two-hybrid), C16orf72 (Positive Genetic), CLEC2D (Two-hybrid), CSGALNACT2 (Two-hybrid), CXCL9 (Two-hybrid), CYSRT1 (Two-hybrid), EMP3 (Two-hybrid), FAM209A (Two-hybrid), GRM2 (Two-hybrid), IGFBP5 (Two-hybrid), IL27RA (Two-hybrid), KRT31 (Two-hybrid), KRTAP1-1 (Two-hybrid)

SIGNOR signaling

2 signaling interactions:

A	Effect	B	Mechanism
CTNNB1	“up-regulates quantity by expression”	CLDN2	“transcriptional regulation”
LEF1	“up-regulates quantity by expression”	CLDN2	“transcriptional regulation”

Enriched among interaction partners

Reactome pathways and GO biological processes over-represented among this gene’s 99 IntAct physical interaction partners (hypergeometric vs the genome-wide background, BH-FDR, gene-set size 15–500, ranked by fold). A functional readout of the neighbourhood — distinct from this gene’s own memberships above, and biased toward well-studied / hub proteins, so read it as themes rather than proof.

Reactome pathways:

Pathway	Partners	Fold	FDR
Trafficking of GluR2-containing AMPA receptors	5	48.7×	3e-06
Ras activation upon Ca2+ influx through NMDA receptor	5	41.4×	6e-06
Unblocking of NMDA receptors, glutamate binding and activation	5	39.4×	6e-06
Negative regulation of NMDA receptor-mediated neuronal transmission	5	39.4×	6e-06
Assembly and cell surface presentation of NMDA receptors	10	36.8×	1e-11
Dopamine Neurotransmitter Release Cycle	5	36.0×	8e-06
Long-term potentiation	5	34.5×	9e-06
Neurexins and neuroligins	11	31.4×	9e-12

GO biological processes:

GO term	Partners	Fold	FDR
establishment or maintenance of epithelial cell apical/basal polarity	11	68.0×	2e-15
protein localization to synapse	6	48.9×	3e-07
receptor clustering	7	46.5×	3e-08
regulation of postsynaptic membrane neurotransmitter receptor levels	7	36.9×	1e-07
protein-containing complex assembly	10	12.1×	1e-06
cell-cell adhesion	10	10.8×	3e-06
chemical synaptic transmission	10	8.2×	2e-05
intracellular signal transduction	10	4.1×	5e-03

Disease & clinical

Genetic variants

Variant evidence for CLDN2: 73 ClinVar records (2 pathogenic / likely pathogenic); 3 GWAS associations. Per-variant detail is on Sugi Variant.

ClinVar

73 variants total. Per-class counts are floors (≥ shown; pagination cap):

Classification	Count (floor)
Pathogenic	1
Likely pathogenic	1
Uncertain significance	27
Likely benign	5
Benign	5

Top pathogenic / likely-pathogenic (2)

Showing all 2 pathogenic / likely-pathogenic ClinVar records, ranked by ClinVar review status (expert panel → multiple submitters → single submitter), then by number of submitting labs.

Variant ID	HGVS	Classification	Review	Submitters
2506548	GRCh37/hg19 Xq22.3(chrX:105066840-106486528)	Likely pathogenic	criteria provided, single submitter	1
488651	NM_020384.4(CLDN2):c.481G>C (p.Gly161Arg)	Pathogenic	no assertion criteria provided	2

Per-variant reference — Sugi Variant

Explore CLDN2’s pathogenic and likely-pathogenic variants individually — each with its ClinVar classification and conditions, applied ACMG criteria (ClinGen expert panel, where curated), the calibrated in-silico predictors (AlphaMissense, REVEL, SaProt, conservation), gnomAD frequency, and the predictor-disagreement QC signal — on Sugi Variant.

SpliceAI

Top 10 splice-impact sites by Δscore (adjacent positions with the same effect merged into one range; 19 predictions of 68):

Position(s)	Effect	Δscore	Sites
X:106920552–106920553	donor_loss	0.9900	5
X:106921356	donor_gain	0.9900
X:106928049–106928050	acceptor_loss	0.9800	6
X:106920553	donor_loss	0.9700
X:106920556	donor_loss	0.9400
X:106921323	donor_gain	0.9100
X:106928038	acceptor_gain	0.8700
X:106920556	donor_loss	0.8500
X:106921358	donor_gain	0.8400
X:106920557	donor_gain	0.8300

AlphaMissense

529 missense substitutions predicted likely pathogenic (of 1,480 scored), across 155 residues. Top 20 hotspot residues, ranked by the number of likely-pathogenic substitutions (of those reachable by a single-nucleotide change), then by mean score:

Residue	Likely-pathogenic substitutions	Mean am_pathogenicity	Max am_pathogenicity
C64	7	0.983	0.996
W30	7	0.982	0.997
C54	7	0.982	0.994
W51	7	0.957	0.995
F147	7	0.930	0.992
S58	7	0.898	0.976
F158	7	0.895	0.978
M102	7	0.888	0.950
F125	7	0.863	0.924
W138	7	0.850	0.961
G49	6	0.977	0.995
K157	6	0.923	0.981
K114	6	0.916	0.975
G60	6	0.913	0.987
G17	6	0.909	0.992
M84	6	0.887	0.980
F46	6	0.877	0.944
G101	6	0.876	0.981
P28	6	0.861	0.934
C104	6	0.838	0.932

HPA cancer prognostics

RNA cancer specificity: Cancer enhanced (Kidney Renal Papillary Cell Carcinoma)

Human Protein Atlas survival analysis — favorable = higher expression predicts better survival.

4 prognostic cancer types:

Cancer	Prognostic	p-value
Kidney Renal Clear Cell Carcinoma (TCGA)	favorable	8.01e-06
Lung Adenocarcinoma (TCGA)	favorable	6.58e-05
Thyroid Carcinoma (TCGA)	favorable	0.0002
Rectum Adenocarcinoma (validation)	unfavorable	0.000877

Disease associations

OMIM: gene MIM:300520 | disease phenotypes: MIM:301060

GenCC curated gene-disease

2 curated gene-disease records:

Disease	Classification	Inheritance	Records
hereditary chronic pancreatitis	Limited	Autosomal dominant
azoospermia, obstructive, with nephrolithiasis	Limited	Unknown

Mondo (3): male infertility (MONDO:0005372), azoospermia, obstructive, with nephrolithiasis (MONDO:0025356), hereditary chronic pancreatitis (MONDO:0008185)

HPO phenotypes

5 phenotypes (HPO-id order):

HPO	Term
HP:0000787	Kidney stone
HP:0001419	X-linked recessive inheritance
HP:0003251	Male infertility
HP:0011962	Obstructive azoospermia
HP:0033808	Spermatocele

GWAS associations

3 associations:

Study	Trait	p-value
GCST004860_123	Alcoholic chronic pancreatitis	2e-29
GCST001741_2	Pancreatitis	2e-22
GCST004860_127	Alcoholic chronic pancreatitis	6e-15

MeSH disease descriptors

2 disease descriptors:

Descriptor	Name	Tree numbers
D007248	Infertility, Male	C12.100.500.430; C12.100.750.700; C12.200.294.430
C537262	Hereditary pancreatitis *(supp.)*

Drugs & pharmacology

Drug and pharmacology data

Is drug target: no

PharmGKB: 1 entry (CPIC guideline: no)

CTD chemical–gene interactions

51 total (human), top 30 by PubMed support.

Chemical	Actions (top 5)	PubMed papers
Cyclosporine	decreases expression	3
sodium arsenite	decreases expression, increases expression	2
(+)-JQ1 compound	decreases expression	2
Acetaminophen	decreases expression	2
Benzo(a)pyrene	affects methylation, increases expression, increases methylation	2
Aflatoxin B1	decreases methylation, increases expression	2
Okadaic Acid	increases expression	2
aristolochic acid I	decreases expression	1
OTX015	decreases expression	1
mivebresib	decreases expression	1
sanguinarine	decreases expression	1
pirinixic acid	affects binding, decreases expression, increases activity	1
bisphenol A	decreases methylation	1
acadesine	increases reaction, decreases expression	1
solasodine	increases reaction, decreases reaction, increases expression, decreases expression	1
ethyl-p-hydroxybenzoate	increases expression	1
butyraldehyde	decreases expression	1
potassium bromate	decreases expression	1
ochratoxin A	decreases expression	1
diallyl disulfide	decreases expression	1
diallyl trisulfide	decreases expression	1
brequinar	decreases expression	1
caffeic acid phenethyl ester	decreases expression, decreases reaction, increases activity, increases response to substance	1
cordycepin	decreases expression	1
CGP 52608	affects binding, increases reaction	1
deguelin	increases expression	1
6-formylindolo(3,2-b)carbazole	decreases reaction, increases expression, affects reaction	1
2-palmitoylglycerol	increases expression	1
abrine	decreases expression	1
Resveratrol	decreases expression, decreases reaction, increases expression	1

Cellosaurus cell lines

1 cell lines: 1 cancer cell line

First 10 cell lines (id-ordered, not curated):

Cellosaurus	Name	Category	Sex
CVCL_C3V8	HT-1080/hCLDN-2	Cancer cell line	Male

Clinical trials (associated diseases)

Via MONDO — disease-level, not drug-specific.

showing 60 of 217 trials:

NCT	Phase	Status	Title
NCT02202382	Phase 4	COMPLETED	Effects of Korean Red Ginseng on Male Infertility
NCT02204826	Phase 4	COMPLETED	Effects of Korean Red Ginseng on Semen Parameters in Male Infertility Patients: a Randomized, Placebo-controlled, Double-blind Clinical Study
NCT03802864	Phase 4	COMPLETED	Post-operative Pain Control of Testicular Sperm Extraction Using Liposomal Bupivacaine
NCT06100432	Phase 4	ACTIVE_NOT_RECRUITING	Effect of Eurycoma Longifolia (DLBS5055) and Multivitamins (Vitamin C+Vitamin E+ β-carotene) for Infertile Males
NCT07523022	Phase 4	ENROLLING_BY_INVITATION	Comparison of the Effect of Gonadotropin and Clomiphene Citrate Treatment on Sperm Parameters and the Outcome of Assisted Reproductive Procedures in Subfertile Men Based on the APHRODITE Groups
NCT00975117	Phase 3	COMPLETED	Spermotrend in the Treatment of Male Infertility
NCT01407432	Phase 3	COMPLETED	Impact of Folates in the Care of the Male Infertility
NCT01895816	Phase 3	COMPLETED	Herbal Tonic Fertile Supplement(ZO2C5)
NCT02605070	Phase 3	TERMINATED	Pilot Study on the Effects of FSH Treatment on the Epigenetic Characteristics of Spermatozoa in Infertile Patients With Severe Oligozoospermia
NCT07402759	Phase 3	ACTIVE_NOT_RECRUITING	Impact of tdrd9 Gene Mutations in the Therapeutic Response to L-carnitine in Oligoasthenozoospermic Men
NCT02871778	Phase 2	COMPLETED	Clearing Lungs With ENaC Inhibition in Primary Ciliary Dyskinesia
NCT07318974	Phase 2	ACTIVE_NOT_RECRUITING	Melatonin Therapy for Improving ICSI Outcomes in Women With Diminished Ovarian Reserve
NCT01880086	Phase 2	COMPLETED	Clomiphene Citrate for the Treatment of Low Testosterone Associated With Chronic Opioid Pain Medication Administration
NCT02061384	Phase 2	COMPLETED	RA-2 13-cis Retinoic Acid (Isotretinoin)
NCT02421887	Phase 2	COMPLETED	Males, Antioxidants, and Infertility Trial
NCT05200663	Phase 2	UNKNOWN	Efficacy Comparison of Tamoxifen and Tamoxifen With Antioxidants on Semen Quality of Male With Idiopathic Infertility
NCT05290558	Phase 2	ACTIVE_NOT_RECRUITING	The Therapeutic Effects of Bu Shen Yi Jing Pill on Semen Quality in Sub Fertile Males: a Randomized Controlled Trial
NCT06091969	Phase 2	NOT_YET_RECRUITING	Supplementation for Male Subfertility
NCT05737485	Phase 1	COMPLETED	Study Evaluating the Safety and Tolerability of RCT1100 in Healthy and PCD Subjects
NCT06600425	Phase 1	COMPLETED	A Study to Assess the Safety, Tolerability, Ciliary Rescue, and Pharmacodynamics of RCT1100 in Adults With PCD
NCT06633757	Phase 1	COMPLETED	Study of Inhaled RCT1100 in Adults With PCD Caused by Pathogenic Mutations in the DNAI1 Gene to Measure Mucociliary Clearance
NCT01595308	Phase 1	COMPLETED	A Pilot Study to Evaluate the Effect of Pomegranate Juice on Semen Parameters in Healthy Male Volunteers
NCT02122211	Phase 1	COMPLETED	Choline Dehydrogenase and Sperm Function: Effects of Betaine
NCT02575924	Phase 1	UNKNOWN	Influence of Culture Media on Clinical Outcomes in Poor Responders or Severe Male Infertility
NCT00830557	Not specified	RECRUITING	Collecting Medical Information and Tissue Samples From Patients With Pancreatic Cancer or Other Pancreatic Disorders
NCT02078245	Not specified	UNKNOWN	Quality Control Study of MR Based Screening of Individual With Increased Risk for Pancreas Cancer.
NCT02206360	Not specified	COMPLETED	Pancreatic Cancer Early Detection Program
NCT02309632	Not specified	WITHDRAWN	Pancreatic Cancer Screening of High-Risk Individuals in Arkansas
NCT04095195	Not specified	RECRUITING	Registry of Subjects at Risk of Pancreatic Cancer
NCT04743479	Not specified	RECRUITING	Artificial Intelligence-based Early Screening of Pancreatic Cancer and High Risk Tracing (ESPRIT-AI)
NCT07413029	Not specified	RECRUITING	French National Cohort of Patients With PRSS1 Mutations
NCT07700992	Not specified	RECRUITING	A Liquid Biopsy for Pancreatic Cancer Early-detection and Disease Monitoring
NCT04901715	Early Phase 1	COMPLETED	Functional Studies of Novel Genes Mutated in Primary Ciliary Dyskinesia II: Genotype to Phenotype
NCT00005650	Not specified	COMPLETED	Genetic Study of Patients With Primary Ciliary Dyskinesia
NCT00323167	Not specified	COMPLETED	Rare Genetic Disorders of the Breathing Airways
NCT00368446	Not specified	COMPLETED	Genetic Disorders of Mucociliary Clearance in Nontuberculous Mycobacterial Lung Disease
NCT00450918	Not specified	COMPLETED	Evaluating Progression of and Diagnostic Tools for Primary Ciliary Dyskinesia in Children and Adolescents
NCT00608556	Not specified	COMPLETED	Dyskinesia, Heterotaxy and Congenital Heart Disease
NCT00686309	Not specified	UNKNOWN	Comparison of On-line and Off-line Measurements of Exhaled Nitric Oxide (NO)
NCT00722878	Not specified	COMPLETED	Long-term Lung Function and Disease Progression in Children With Early Onset Primary Ciliary Dyskinesia Lung Disease
NCT00739817	Not specified	UNKNOWN	Screening for Primary Ciliary Dyskinesia Using Nasal Nitric Oxide
NCT00783887	Not specified	COMPLETED	Diagnosis of Primary Ciliary Dyskinesia
NCT00807482	Not specified	RECRUITING	Pathogenesis of Primary Ciliary Dyskinesia (PCD) Lung Disease
NCT01070914	Not specified	UNKNOWN	Early Detection and Characterization of Primary Ciliary Dyskinesia
NCT01155115	Not specified	COMPLETED	Inflammatory and Microbiologic Markers in Sputum: Comparing Cystic Fibrosis With Primary Ciliary Dyskinesia
NCT01246258	Not specified	COMPLETED	Otolith Function in Patients With Primary Ciliary Dyskinesia
NCT01929356	Not specified	UNKNOWN	Chest Physiotherapy and Lung Function in Primary Ciliary Dyskinesia
NCT02389049	Not specified	COMPLETED	Genetics of Primary Ciliary Dyskinesia
NCT02419365	Not specified	RECRUITING	International Primary Ciliary Dyskinesia (PCD) Registry
NCT02622061	Not specified	COMPLETED	NIOX VERO Nasal Application in Primary Ciliary Dyskinesia
NCT02699177	Not specified	UNKNOWN	In Vivo Measurements of Nasal Ciliary Beat Frequency by Using Interferometry
NCT02704455	Not specified	NOT_YET_RECRUITING	Registry Study on Primary Ciliary Dyskinesia in Chinese Children
NCT03271840	Not specified	COMPLETED	Registry for Primary Ciliary Dyskinesia
NCT03279965	Not specified	UNKNOWN	MRI in Cystic Fibrosis and Primary Ciliary Dyskinesia
NCT03320382	Not specified	UNKNOWN	Multiple Breath Washout, a Clinimetric Dataset
NCT03370029	Not specified	COMPLETED	Respiratory Muscle Strength, Exercise Capacity and Physical Activity Levels in Children Primary Ciliary Dyskinesia
NCT03494894	Not specified	COMPLETED	Bacteriological Link Between Upper and Lower Airways in Cystic Fibrosis and Primary Ciliary Dyskinesia
NCT03517865	Not specified	ACTIVE_NOT_RECRUITING	International Primary Ciliary Dyskinesia Cohort
NCT03606200	Not specified	RECRUITING	Swiss Primary Ciliary Dyskinesia Registry
NCT03704207	Not specified	RECRUITING	Utility of PCD Diagnostics to Improve Clinical Care