intellectual disability, X-linked 81

Summary

intellectual disability, X-linked 81 (MONDO:0010324) is a disease with 1 cohort gene.

At a glance

• Cohort genes: 1
• ClinVar variants: 1

Clinical features

No curated clinical features (Orphanet) for this disease.

Identifiers

Disease identifiers

Field	Value
Canonical name	intellectual disability, X-linked 81
Mondo ID	MONDO:0010324
MeSH	C564515
OMIM	300433
DOID	DOID:0112033
UMLS	C1845531
MedGen	335203
GARD	0022676
Is cancer (heuristic)	no

Also known as: intellectual disability, X-linked 81 · mental retardation, X-linked 81 · mental retardation, X-linked 81, X-linked recessive · MRX81

Data availability: 1 ClinVar variant.

Disease family

Classification path: disease › human disease › disease by body system or component › nervous system disorder › neurodevelopmental disorder › intellectual disability › non-syndromic intellectual disability › non-syndromic X-linked intellectual disability › intellectual disability, X-linked 81

Related subtypes (51): intellectual disability, X-linked 23, intellectual disability, X-linked 20, intellectual disability, X-linked 14, intellectual disability, X-linked 50, intellectual disability, X-linked 21, intellectual disability, X-linked 58, intellectual disability, X-linked 72, intellectual disability, X-linked 53, intellectual disability, X-linked 73, intellectual disability, X-linked 42, intellectual disability, X-linked 63, intellectual disability, X-linked, with or without seizures, ARX-related, intellectual disability, X-linked 2, intellectual disability, X-linked 46, intellectual disability, X-linked 77, intellectual disability, X-linked 45, intellectual disability, X-linked 84, intellectual disability, X-linked 82, intellectual disability, X-linked 30, intellectual disability, X-linked 91, intellectual disability, X-linked 93, chromosome Xp11.22 duplication syndrome, intellectual disability, X-linked 95, intellectual disability, X-linked 96, intellectual disability, X-linked 97, intellectual disability, X-linked 19, intellectual disability, X-linked 89, intellectual disability, X-linked 41, intellectual disability, X-linked 90, intellectual disability, X-linked 92, intellectual disability, X-linked 88, intellectual disability, X-linked 99, intellectual disability, X-linked 100, intellectual disability, X-linked 101, intellectual disability, X-linked 102, intellectual disability, X-linked 61, intellectual disability, X-linked 103, intellectual disability, X-linked 104, intellectual disability, X-linked 105, intellectual disability, X-linked 1, methylmalonic acidemia with homocystinuria, type cblX, FRAXE intellectual disability, intellectual disability, X-linked 9, intellectual developmental disorder, X-linked 108, intellectual disability, X-linked 106, intellectual disability, X-linked 107, intellectual developmental disorder, X-linked 110, intellectual developmental disorder, X-linked 111, intellectual developmental disorder, X-linked 112, intellectual developmental disorder, X-linked 113, intellectual developmental disorder, X-linked 114

Genetics & variants

GWAS landscape

No GWAS associations recorded — common-variant (GWAS) studies don’t cover this disease (typical for Mendelian / rare diseases). See the curated gene cohort and Mendelian overlap below.

Variant details and genetic-evidence tiers

ClinVar germline variants

1 retrieved; paginated sample, class counts are floors:

1 uncertain significance

ClinVar	Variant (HGVS)	Gene	Classification	Review
1691406	NM_001830.4(CLCN4):c.206C>T (p.Ser69Leu)	CLCN4	Uncertain significance	criteria provided, multiple submitters, no conflicts

Genes & proteins

Mendelian disease overlap and somatic drivers

GenCC: 0 · Orphanet: 2 · OMIM-shared: 0 · Dual-evidence (GWAS+Mendelian): 0

Orphanet rare-disease linkage (cohort genes)

Gene	Orphanet ID	Rare disease
CLCN4	Orphanet:485350	CLCN4-related X-linked intellectual disability syndrome
CLCN4	Orphanet:777	X-linked non-syndromic intellectual disability

Cohort genes → proteins

1 cohort genes, 1 distinct canonical proteins.

Evidence partition

Subset	Genes
multi_evidence	1

Cohort genes (full)

Symbol	HGNC	Ensembl	UniProt	Name	Evidence
CLCN4	HGNC:2022	ENSG00000073464	P51793	H(+)/Cl(-) exchange transporter 4	clinvar

Cohort function summary

Lead sentence per gene, UniProt-curated.

Symbol	Protein name	Function (lead sentence)
CLCN4	H(+)/Cl(-) exchange transporter 4	Strongly outwardly rectifying, electrogenic H(+)/Cl(-)exchanger which mediates the exchange of chloride ions against protons.

Protein-family classification

Druggable: 0 · Difficult: 0 · Unknown: 1 · Druggable fraction: 0.0

Family distribution

Cohort families vs a genome-wide background (hypergeometric, BH-FDR; fold = observed/expected). Counts kept; sorted by enrichment, so the catch-all Other/Unknown bucket no longer leads.

Family	Genes	Fold	FDR
Other/Unknown	1	1.8×	0.558

Per-gene assignment

Symbol	Family	Druggable?	EC	InterPro (top 3)
CLCN4	Other/Unknown	no		CBS_dom, ClC, Cl_channel-4

Expression context

Cohort genes with no expression data: 0.

1 cohort gene are a single-cell marker in ≥1 SCXA experiment.

Breadth distribution (Bgee present_calls)

Bucket	Genes
narrow (1-5 tissues)	0
moderate (6-20)	0
broad (>20)	1
unknown	0

Top tissues across cohort

Tissue	Cohort genes
Brodmann (1909) area 23	1
middle temporal gyrus	1
postcentral gyrus	1

Per-gene tissue summary (top 30)

Symbol	Bgee breadth	FANTOM5 breadth	SCXA	Top tissues
CLCN4	247	ubiquitous	marker	middle temporal gyrus, Brodmann (1909) area 23, postcentral gyrus

Protein interactions among cohort

Intra-cohort edges: 0.

Hub genes (top 10 by interactor count)

Symbol	Interactor count
CLCN4	962

Structural data

PDB: 0 · AlphaFold-only: 1 · No structure: 0

AlphaFold-only cohort genes (top 30 by pLDDT)

Symbol	UniProt	pLDDT
CLCN4	P51793	84.66

Function

Pathway analysis

Distinct Reactome pathways touched by cohort: 1. Enrichment computed across 1 evidence-associated genes (1 with Reactome annotation).

Pathways by enrichment

Over-representation of cohort genes vs the genome-wide background (hypergeometric test, Benjamini-Hochberg FDR; fold = observed/expected over 1 annotated cohort genes). Counts and members are kept as ground-truth; sorted by enrichment.

Pathway	Cohort genes	Fold	FDR	Sample cohort genes
Stimuli-sensing channels	1	135.9×	0.007	CLCN4

GO biological processes by enrichment

Over-representation of cohort genes vs the genome-wide background (hypergeometric test, Benjamini-Hochberg FDR; fold = observed/expected over 1 annotated cohort genes). Counts and members are kept as ground-truth; sorted by enrichment.

GO term	Cohort genes	Fold	FDR	Sample cohort genes
chloride transport	1	455.5×	0.005	CLCN4
non-motile cilium assembly	1	290.6×	0.005	CLCN4
monoatomic ion transmembrane transport	1	208.1×	0.005	CLCN4

Therapeutics

Drug target analysis

Approved (phase 4): 0 · Phase ≥3: 0 · Phased (≥1): 0 · Undrugged: 1

Druggability breadth: 0 of 1 evidence-associated genes (0%) have a ChEMBL target (buckets above are over the deeply-mined display cohort).

Top cohort targets by molecule count

Symbol	Molecules	Max phase
CLCN4	0	0

Bioactivity and enzyme data

Enzyme cohort genes (≥1 EC): 0.

Pharmacogenomics

Cohort genes with a PharmGKB record: 1; with CPIC/DPWG dosing guidelines: 0.

No cohort gene has a CPIC/DPWG genotype-guided dosing guideline (PharmGKB).

Chemical tractability of cohort targets

0 approved/phased compounds have measured bioactivity against a cohort gene (and aren’t yet in disease-level trials). This is a research / tractability signal, NOT a therapeutic recommendation — a bioactivity row often reflects off-target or screening binding (e.g. promiscuous kinase inhibitors against a cohort kinase), implying no disease mechanism.

Druggability pyramid

Cohort genes binned by druggability tier (high → low):

Tier	Definition	Genes	Symbols
A	Approved (phase 4 drug)	0
B	Phased (≥1) drug, not yet approved	0
C	Druggable family + PDB, no drug	0
D	Druggable family + AlphaFold only, no drug	0
E	Difficult family or no structure, no drug	1	CLCN4

Undrugged target profiles

1 cohort genes are undrugged. Ranked by ‘starting-point quality’ (assay depth + drugged-partner adjacency).

Symbol	ChEMBL assays	Drugged partners (top 3)
CLCN4	0	—

Clinical trials & evidence

Clinical trials

Clinical trials: 0.