CNGA2

Summary

CNGA2 (cyclic nucleotide gated channel subunit alpha 2, HGNC:2149) is a protein-coding gene on chromosome Xq28, encoding Cyclic nucleotide-gated channel alpha-2 (Q16280). Pore-forming subunit of the olfactory cyclic nucleotide-gated channel.

The protein encoded by this gene represents the alpha subunit of a cyclic nucleotide-gated olfactory channel. The encoded protein contains a carboxy-terminal leucine zipper that mediates channel formation.

Source: NCBI Gene 1260 — RefSeq curated summary.

At a glance

• Gene–disease (curated): isolated congenital anosmia (Supportive, GenCC) — +1 more curated relationship
• Clinical variants (ClinVar): 96 total — 1 pathogenic
• MANE Select transcript: NM_005140

Identifiers

Gene identifiers

Field	Value
HGNC ID	HGNC:2149
Approved symbol	CNGA2
Name	cyclic nucleotide gated channel subunit alpha 2
Location	Xq28
Locus type	gene with protein product
Status	Approved
Aliases	CNG2, OCNC1, OCNCa, OCNCALPHA, OCNCalpha, FLJ46312
Ensembl gene	ENSG00000183862
Ensembl biotype	protein_coding
OMIM	300338
Entrez	1260

Gene structure

Transcript identifiers

Ensembl transcripts: 1 — 1 protein_coding

ENST00000329903

RefSeq mRNA: 1 — MANE Select: NM_005140 NM_005140

CCDS: CCDS14701

Canonical transcript exons

ENST00000329903 — 7 exons

Exon	Start	End
ENSE00001317113	151743093	151745564
ENSE00001366348	151738787	151738879
ENSE00001374857	151740794	151740901
ENSE00001376447	151742536	151742642
ENSE00001381209	151739562	151739732
ENSE00001452431	151738458	151738593
ENSE00003929921	151734746	151734943

Expression profiles

Bgee: expression breadth tissue_specific, 2 present calls, max score 37.20.

Top tissues by expression

130 total, by Bgee expression score (0-100, higher = more expressed):

Tissue	Anatomy ID	Expression score	Quality
colonic epithelium	UBERON:0000397	37.20	gold quality
ventricular zone	UBERON:0003053	36.48	gold quality
cortical plate	UBERON:0005343	36.47	gold quality
bone marrow cell	CL:0002092	36.16	gold quality
ganglionic eminence	UBERON:0004023	35.49	gold quality
skeletal muscle tissue	UBERON:0001134	33.38	gold quality
hindlimb stylopod muscle	UBERON:0004252	32.15	gold quality
bone marrow	UBERON:0002371	31.74	gold quality
muscle tissue	UBERON:0002385	31.06	gold quality
sural nerve	UBERON:0015488	30.93	gold quality
stromal cell of endometrium	CL:0002255	29.87	gold quality
prefrontal cortex	UBERON:0000451	29.35	gold quality
urinary bladder	UBERON:0001255	28.42	gold quality
duodenum	UBERON:0002114	28.14	gold quality
liver	UBERON:0002107	28.04	gold quality
lymph node	UBERON:0000029	27.57	gold quality
olfactory segment of nasal mucosa	UBERON:0005386	27.32	gold quality
tonsil	UBERON:0002372	27.05	gold quality
leukocyte	CL:0000738	26.95	gold quality
monocyte	CL:0000576	26.89	gold quality
islet of Langerhans	UBERON:0000006	26.55	gold quality
vermiform appendix	UBERON:0001154	26.42	gold quality
blood	UBERON:0000178	26.25	gold quality
gall bladder	UBERON:0002110	25.98	gold quality
placenta	UBERON:0001987	25.81	gold quality
muscle of leg	UBERON:0001383	25.59	gold quality
endometrium	UBERON:0001295	25.05	gold quality
calcaneal tendon	UBERON:0003701	24.76	gold quality
primary visual cortex	UBERON:0002436	24.61	gold quality
pancreas	UBERON:0001264	24.42	gold quality

Single-cell (SCXA)

Detected in 1 experiment(s), a significant marker in 0.

Experiment	Marker?	Max mean expression
E-ANND-3	no	2.46

Regulation

Is transcription factor: no

Upstream regulators (CollecTRI, top): EBF1

miRNA regulators (miRDB)

51 targeting CNGA2, top 30 by miRDB confidence (max_score; target_count = how many genes the miRNA targets in total — lower means more specific):

miRNA	Max score	Avg score	miRNA target_count
HSA-MIR-22-3P	99.93	68.13	917
HSA-MIR-3671	99.90	73.04	3897
HSA-MIR-6780A-5P	99.88	66.69	2776
HSA-MIR-4728-5P	99.85	69.39	4718
HSA-MIR-6785-5P	99.82	68.68	4428
HSA-MIR-1273H-5P	99.77	66.32	2471
HSA-MIR-4319	99.76	69.83	2586
HSA-MIR-149-3P	99.72	68.22	3963
HSA-MIR-4306	99.72	70.50	3630
HSA-MIR-6752-3P	99.72	66.71	1587
HSA-MIR-30B-3P	99.70	65.76	2325
HSA-MIR-3689A-3P	99.70	65.73	2306
HSA-MIR-3689B-3P	99.70	65.71	2311
HSA-MIR-3689C	99.70	65.71	2311
HSA-MIR-6779-5P	99.70	65.76	2363
HSA-MIR-6883-5P	99.69	68.05	3785
HSA-MIR-5700	99.64	69.88	2280
HSA-MIR-4666B	99.64	68.69	1282
HSA-MIR-7106-5P	99.53	67.47	3574
HSA-MIR-4441	99.49	66.56	3216
HSA-MIR-1324	99.46	66.57	1302
HSA-MIR-185-5P	99.35	68.60	2497
HSA-MIR-4644	99.35	69.12	2514
HSA-MIR-4796-5P	99.34	70.06	810
HSA-MIR-8085	99.28	67.56	2362
HSA-MIR-6731-5P	99.28	67.42	2375
HSA-MIR-140-3P	99.04	67.69	1324
HSA-MIR-6506-5P	99.04	65.66	1386
HSA-MIR-4270	99.02	66.26	1987
HSA-MIR-154-5P	98.92	66.65	733

Literature-anchored findings (GeneRIF, showing 3)

• The results showed that it is predominantly the charge of the E342 residue in the P-loop, rather than the pore helix dipoles, which controls the cation-anion selectivity of the CNGA2 channel. (PMID:16533895)
• Identification of a novel X-linked stop mutation in CNGA2 (c.634C>T, p.R212*) in two brothers with isolated congenital anosmia. (PMID:25156905)
• The studies findings provides strong support for role of CNGA2 gene with pathogenicity of isolated congenital anosmia in humans. Together, these results indicate that mutations in key olfactory signaling pathway genes are responsible for human disease. (PMID:28572688)

Cross-species orthologs

8 orthologs

Organism	Symbol	Gene ID
danio_rerio	cnga2b	ENSDARG00000100436
danio_rerio	cnga2a	ENSDARG00000102968
mus_musculus	Cnga2	ENSMUSG00000005864
rattus_norvegicus	Cnga2	ENSRNOG00000030119
drosophila_melanogaster	CngA	FBGN0261612
caenorhabditis_elegans		WBGENE00000487
caenorhabditis_elegans		WBGENE00006526
caenorhabditis_elegans		WBGENE00022295

Paralogs (17): KCNH2 (ENSG00000055118), CNGB1 (ENSG00000070729), KCNH4 (ENSG00000089558), HCN2 (ENSG00000099822), CNGA4 (ENSG00000132259), KCNH3 (ENSG00000135519), HCN4 (ENSG00000138622), KCNH5 (ENSG00000140015), KCNH1 (ENSG00000143473), HCN3 (ENSG00000143630), CNGA3 (ENSG00000144191), HCN1 (ENSG00000164588), CNGB3 (ENSG00000170289), KCNH6 (ENSG00000173826), KCNH8 (ENSG00000183960), KCNH7 (ENSG00000184611), CNGA1 (ENSG00000198515)

Protein

Protein identifiers

Cyclic nucleotide-gated channel alpha-2 — Q16280 (reviewed: Q16280)

Alternative names: Olfactory cyclic nucleotide-gated channel subunit 1

All UniProt accessions (1): Q16280

UniProt curated annotations — full annotation on UniProt →

Function. Pore-forming subunit of the olfactory cyclic nucleotide-gated channel. Operates in the cilia of olfactory sensory neurons where chemical stimulation of the odorant is converted to an electrical signal. Mediates odorant-induced cAMP-dependent Ca(2+) influx triggering neuron depolarization. The rise of intracellular Ca(2+) levels potentiates the olfactory response by activating Ca(2+)-dependent Cl(-) channels, but it also serves as a negative feedback signal to desensitize the channel for rapid adaptation to odorants. Conducts cAMP- and cGMP-gated ion currents, with permeability for monovalent and divalent cations.

Subunit / interactions. The olfactory cyclic nucleotide-gated channel is an heterotetramer composed of CNGA2, CNGA4 and CNGB1b subunits with 2:1:1 stoichiometry.

Subcellular location. Cell projection. Cilium membrane.

Domain organisation. The C-terminal coiled-coil domain mediates trimerization of CNGA subunits.

Similarity. Belongs to the cyclic nucleotide-gated cation channel (TC 1.A.1.5) family. CNGA2 subfamily.

RefSeq proteins (1): NP_005131* (*=MANE)

Domains & families (InterPro)

ID	Name	Type
IPR000595	cNMP-bd_dom	Domain
IPR005821	Ion_trans_dom	Domain
IPR014710	RmlC-like_jellyroll	Homologous_superfamily
IPR018488	cNMP-bd_CS	Conserved_site
IPR018490	cNMP-bd_dom_sf	Homologous_superfamily
IPR032406	CLZ_dom	Domain
IPR050866	CNG_cation_channel	Family

Pfam: PF00027, PF00520, PF16526

Catalyzed reactions (Rhea), 7 shown:

• NH4(+)(in) = NH4(+)(out) (RHEA:28747)
• K(+)(in) = K(+)(out) (RHEA:29463)
• Ca(2+)(in) = Ca(2+)(out) (RHEA:29671)
• Na(+)(in) = Na(+)(out) (RHEA:34963)
• Rb(+)(in) = Rb(+)(out) (RHEA:78547)
• Li(+)(in) = Li(+)(out) (RHEA:78551)
• Cs(+)(in) = Cs(+)(out) (RHEA:78555)

UniProt features (37 total): topological domain 7, transmembrane region 7, region of interest 6, binding site 6, sequence variant 5, compositionally biased region 2, site 2, chain 1, coiled-coil region 1

Structure

Experimental structures (PDB)

2 structures.

PDB	Method	Resolution (Å)
9UPG	ELECTRON MICROSCOPY	2.87
9UPF	ELECTRON MICROSCOPY	3.59

Predicted structure (AlphaFold)

Model	pLDDT	Fraction very-high
AF-Q16280-F1	78.41	0.46

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 (2): 364 (central gate); 368 (central gate)

Ligand- & substrate-binding residues (6): 520; 523; 536; 536; 537; 537

Function

Pathways and Gene Ontology

Reactome pathways

2 pathways

ID	Pathway
R-HSA-381753	Olfactory Signaling Pathway
R-HSA-5620916	VxPx cargo-targeting to cilium

MSigDB gene sets: 96 (showing top): GOBP_POTASSIUM_ION_TRANSPORT, GOBP_SENSORY_PERCEPTION_OF_CHEMICAL_STIMULUS, GOBP_MONOATOMIC_CATION_TRANSPORT, SHETH_LIVER_CANCER_VS_TXNIP_LOSS_PAM4, GOCC_GOLGI_ASSOCIATED_VESICLE, GOBP_SENSORY_PERCEPTION, GOBP_CALCIUM_ION_TRANSMEMBRANE_TRANSPORT, GOBP_TRANSMEMBRANE_TRANSPORT, GOBP_SODIUM_ION_TRANSPORT, GOCC_CELL_PROJECTION_MEMBRANE, GOCC_GOLGI_ASSOCIATED_VESICLE_MEMBRANE, GOCC_CATION_CHANNEL_COMPLEX, YAO_TEMPORAL_RESPONSE_TO_PROGESTERONE_CLUSTER_7, GOCC_TRANSPORTER_COMPLEX, GOCC_MEMBRANE_PROTEIN_COMPLEX

GO Biological Process (10): potassium ion transport (GO:0006813), sodium ion transport (GO:0006814), calcium ion transport (GO:0006816), sensory perception of chemical stimulus (GO:0007606), sensory perception of smell (GO:0007608), monoatomic cation transmembrane transport (GO:0098655), monoatomic ion transport (GO:0006811), monoatomic ion transmembrane transport (GO:0034220), transmembrane transport (GO:0055085), calcium ion transmembrane transport (GO:0070588)

GO Molecular Function (9): intracellularly cAMP-activated cation channel activity (GO:0005222), intracellularly cGMP-activated cation channel activity (GO:0005223), calcium channel activity (GO:0005262), calmodulin binding (GO:0005516), cAMP binding (GO:0030552), cGMP binding (GO:0030553), nucleotide binding (GO:0000166), monoatomic ion channel activity (GO:0005216), intracellularly cyclic nucleotide-activated monoatomic cation channel activity (GO:0005221)

GO Cellular Component (7): plasma membrane (GO:0005886), intracellular cyclic nucleotide activated cation channel complex (GO:0017071), Golgi-associated vesicle membrane (GO:0030660), ciliary membrane (GO:0060170), non-motile cilium membrane (GO:0098804), membrane (GO:0016020), cell projection (GO:0042995)

Reactome top-level categories

Rollup of top-2 pathways:

Category	Pathways
Sensory Perception	1
Cargo trafficking to the periciliary membrane	1

GO top-level categories

Rollup of top GO terms by namespace:

Category	Terms
metal ion transport	3
transport	2
intracellularly cyclic nucleotide-activated monoatomic cation channel activity	2
cyclic nucleotide binding	2
anion binding	2
bounding membrane of organelle	2
cellular anatomical structure	2
sensory perception	1
sensory perception of chemical stimulus	1
monoatomic cation transport	1
monoatomic ion transmembrane transport	1
monoatomic ion transport	1
transmembrane transport	1
cellular process	1
calcium ion transport	1
monoatomic cation transmembrane transport	1
monoatomic cation channel activity	1
calcium ion transmembrane transporter activity	1
protein binding	1
adenyl ribonucleotide binding	1
guanyl ribonucleotide binding	1
nucleoside phosphate binding	1
heterocyclic compound binding	1
monoatomic ion transmembrane transporter activity	1
channel activity	1
intracellularly ligand-gated monoatomic ion channel activity	1
cyclic nucleotide-activated monoatomic ion channel activity	1
ligand-gated monoatomic cation channel activity	1
membrane	1
cell periphery	1
cation channel complex	1
Golgi-associated vesicle	1
cytoplasmic vesicle membrane	1
cilium	1
cell projection membrane	1
ciliary membrane	1
non-motile cilium	1

Protein interactions and networks

STRING

1046 interactions, top by confidence (×1000):

Protein A	Protein B	Partner UniProt	Score
CNGA2	CNGB1	Q14028	987
CNGA2	CNGA4	Q8IV77	982
CNGA2	ADCY3	O60266	885
CNGA2	CNGA3	Q16281	784
CNGA2	OMP	P47874	774
CNGA2	ANO2	Q9NQ90	764
CNGA2	BEST2	Q8NFU1	721
CNGA2	GNAL	P38405	696
CNGA2	RTP1	P59025	674
CNGA2	RTP2	Q5QGT7	644
CNGA2	ADCY8	P40145	606
CNGA2	CALM1	P02593	606
CNGA2	CALML6	Q8TD86	606
CNGA2	CALML3	P27482	600
CNGA2	CALML4	Q96GE6	600
CNGA2	CALML5	Q9NZT1	600

IntAct

0 interactions, top by confidence:

BioGRID (1): CNGA2 (Affinity Capture-MS)

ESM2 similar proteins: A0A0M3R8G1, A0A0M4FLW6, A9YWR6, B8ALI0, B8BDK8, B9FMX4, D3GE74, D3ZCM3, D4AYW0, O18866, O18867, O80946, P45843, P45844, P93025, Q00195, Q03041, Q03720, Q08460, Q12791, Q16280, Q28204, Q28718, Q5W274, Q62398, Q62976, Q64343, Q7XA72, Q84K47, Q8GU83, Q8H8V7, Q8RWI9, Q8RXN0, Q90ZC7, Q91WA9, Q93YS4, Q96290, Q9BG98, Q9C8J8, Q9C8K2

Diamond homologs: A0A8I5ZN27, A5K0N4, E1AZ71, P29973, P29974, P36600, P55934, Q00194, Q00195, Q03041, Q03611, Q14028, Q16280, Q16281, Q24278, Q28181, Q28279, Q28718, Q29441, Q2K5E1, Q3UW12, Q62398, Q62927, Q64359, Q8I719, Q8IV77, Q8MJD7, Q8TF77, Q90805, Q90980, Q9ER33, Q9JJZ8, Q9JJZ9, Q9NQW8, W7JX98, Q6BZG7, P49605, Q9LD40, Q03042, A0A509AKL0

SIGNOR signaling

0 interactions.

Disease & clinical

Clinical variants and AI predictions

ClinVar

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

Classification	Count (floor)
Pathogenic	1
Likely pathogenic	0
Uncertain significance	74
Likely benign	8
Benign	10

Top pathogenic / likely-pathogenic (1)

Variant ID	HGVS	Classification
147587	GRCh38/hg38 Xq28(chrX:151159662-152145800)x2	Pathogenic

SpliceAI

604 predictions. Top by Δscore:

Variant	Effect	Δscore
X:151738590:GCAG:G	donor_gain	1.0000
X:151738591:CAGG:C	donor_loss	1.0000
X:151738592:AGG:A	donor_loss	1.0000
X:151738594:GT:G	donor_loss	1.0000
X:151738785:A:AG	acceptor_gain	1.0000
X:151738786:G:GG	acceptor_gain	1.0000
X:151738861:G:T	donor_gain	1.0000
X:151738878:AGG:A	donor_loss	1.0000
X:151738881:T:A	donor_loss	1.0000
X:151739561:GGATA:G	acceptor_gain	1.0000
X:151739686:G:GT	donor_gain	1.0000
X:151739710:G:GT	donor_gain	1.0000
X:151739719:G:GT	donor_gain	1.0000
X:151739733:G:GG	donor_gain	1.0000
X:151739764:GGCTT:G	donor_gain	1.0000
X:151739765:GCTT:G	donor_gain	1.0000
X:151739782:G:GT	donor_gain	1.0000
X:151739782:G:T	donor_gain	1.0000
X:151742534:A:AG	acceptor_gain	1.0000
X:151742535:G:GG	acceptor_gain	1.0000
X:151742535:GA:G	acceptor_gain	1.0000
X:151743089:CTA:C	acceptor_loss	1.0000
X:151743090:TAGGT:T	acceptor_loss	1.0000
X:151743091:A:AC	acceptor_loss	1.0000
X:151743091:A:AG	acceptor_gain	1.0000
X:151743092:G:GG	acceptor_gain	1.0000
X:151738594:G:GG	donor_gain	0.9900
X:151738782:T:TA	acceptor_gain	0.9900
X:151738783:GCAG:G	acceptor_loss	0.9900
X:151738785:AG:A	acceptor_gain	0.9900

AlphaMissense

4398 scored. Top likely-pathogenic:

Variant	Protein change	am_pathogenicity
X:151743501:T:C	L333P	1.000
X:151743519:G:A	G339E	1.000
X:151743593:T:C	F364L	1.000
X:151743595:T:A	F364L	1.000
X:151743595:T:G	F364L	1.000
X:151743336:T:C	L278P	0.999
X:151743422:T:A	W307R	0.999
X:151743422:T:C	W307R	0.999
X:151743424:G:C	W307C	0.999
X:151743424:G:T	W307C	0.999
X:151743484:C:G	C327W	0.999
X:151743495:C:T	S331F	0.999
X:151743507:T:A	L335H	0.999
X:151743507:T:C	L335P	0.999
X:151743518:G:A	G339R	0.999
X:151743518:G:C	G339R	0.999
X:151743518:G:T	G339W	0.999
X:151743519:G:T	G339V	0.999
X:151743534:C:A	P344H	0.999
X:151743581:G:C	G360R	0.999
X:151743582:G:A	G360D	0.999
X:151743588:T:A	L362H	0.999
X:151743588:T:C	L362P	0.999
X:151743593:T:A	F364I	0.999
X:151743594:T:C	F364S	0.999
X:151743594:T:G	F364C	0.999
X:151743597:C:A	A365D	0.999
X:151743608:G:A	G369R	0.999
X:151743608:G:C	G369R	0.999
X:151743609:G:A	G369E	0.999

dbSNP variants (sampled 300 via entrez): RS1000433504 (X:151744780 G>A), RS1000689081 (X:151738887 C>T), RS1001228131 (X:151744879 C>G,T), RS1001228808 (X:151739223 A>T), RS1001316632 (X:151745397 A>C,T), RS1001523912 (X:151739282 C>G,T), RS1001667184 (X:151735961 C>T), RS1001739712 (X:151744959 G>T), RS1001817152 (X:151736360 G>T), RS1002721965 (X:151735849 C>G,T), RS1004067165 (X:151733114 T>C), RS1004130740 (X:151733966 C>A,G,T), RS1005168344 (X:151738072 A>G), RS1005395192 (X:151733821 C>T), RS1005853757 (X:151740999 C>G,T)

Disease associations

OMIM: gene MIM:300338 | disease phenotypes:

GenCC curated gene-disease

Disease	Classification	Inheritance
isolated congenital anosmia	Supportive	Autosomal dominant
anosmia	Limited	X-linked

Mondo (3): congenital portosystemic shunt (MONDO:0018811), anosmia (MONDO:0010528), isolated congenital anosmia (MONDO:0007137)

Orphanet (1): Congenital portosystemic shunt (Orphanet:480531)

HPO phenotypes

0 total (0 of 0 shown, HPO-id order):

GWAS associations

0 associations (top):

MeSH disease descriptors (2)

Descriptor	Name	Tree numbers
D000857	Olfaction Disorders	C10.597.751.600; C23.888.592.763.550
C535983	Congenital anosmia (supp.)

Drugs & pharmacology

Drug and pharmacology data

Is drug target: no

PharmGKB: 1 entry (VIP=true, CPIC=false)

GtoPdb / IUPHAR curated pharmacology

(IUPHAR/BPS Guide to Pharmacology — expert-curated)

Target class: vgic — Cyclic nucleotide-regulated channels (CNG)

Most potent curated ligand interactions (7 total), top 7:

Ligand	Action	Affinity	Parameter
calmodulin	Antagonist	8.5	pIC50
pseudechetoxin	Antagonist	8.3	pKi
cyclic GMP	Agonist	5.76	pEC50
dequalinium	Antagonist	5.6	pIC50
all-trans-retinal	Antagonist	4.57	pIC50
cyclic AMP	Agonist	4.34	pEC50
L-(cis)-diltiazem	Antagonist	2.12	pKi

CTD chemical–gene interactions

4 total (human), top 4 by PubMed support.

Chemical	Actions (top 5)	PubMed papers
geraniol	increases reaction, increases secretion	1
denatonium	decreases reaction, increases secretion	1
CGP 52608	affects binding, increases reaction	1
Benzo(a)pyrene	decreases methylation	1

Clinical trials (associated diseases)

57 trials via MONDO — disease-level, not drug-specific.

Trial	Phase	Status	Title
NCT04528329	PHASE4	UNKNOWN	Anosmia and / or Ageusia and Early Corticosteroid Use
NCT04797936	PHASE4	COMPLETED	BNO 1030 Extract (Imupret) in the Treatment of Mild Forms of COVID-19
NCT04853836	PHASE4	COMPLETED	Olfactory Disfunction and Co-ultraPEALut
NCT03680911	PHASE3	TERMINATED	NAC for Head Trauma-induced Anosmia
NCT04361474	PHASE3	COMPLETED	Trial Evaluating the Efficacy of Local Budesonide Therapy in the Management of Hyposmia in COVID-19 Patients Without Signs of Severity
NCT04484493	PHASE3	COMPLETED	Corticosteroid Nasal Spray in COVID-19 Anosmia
NCT05461365	PHASE3	COMPLETED	Intranasal Insulin for COVID-19-related Smell Loss
NCT07151703	PHASE3	NOT_YET_RECRUITING	Topical Versus Injection PRP for Olfactory Dysfunction
NCT03990766	PHASE2	COMPLETED	Smell Changes & Efficacy of Nasal Theophylline
NCT04422275	PHASE2	WITHDRAWN	Coronavirus Smell Therapy for Anosmia Recovery
NCT04495816	PHASE2	COMPLETED	COVID-19 Anosmia Study
NCT04657809	PHASE2	COMPLETED	Clinical Assessment of Insulin Fast Dissolving Film in Treatment of Post Infection Anosmia
NCT04715932	PHASE2	COMPLETED	Study of Hesperidin Therapy on COVID-19 Symptoms (HESPERIDIN)
NCT04789499	PHASE2	COMPLETED	Smell in Covid-19 and Efficacy of Nasal Theophylline
NCT05184192	PHASE2	COMPLETED	Efficacy of Gabapentin for Post-Covid-19 Olfactory Dysfunction
NCT06204432	PHASE2	ACTIVE_NOT_RECRUITING	Sodium Citrate in Smell Retraining for People With Post-COVID-19 Olfactory Dysfunction
NCT06498687	PHASE1	WITHDRAWN	Theophylline Nasal Spray for PD-Related Hyposmia and Anosmia
NCT04951362	PHASE2/PHASE3	UNKNOWN	Role of Ivermectin Nanosuspension as Nasal Spray in Treatment of Persistant Post covid19 Anosmia
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