BCAP31

Chr X

B cell receptor associated protein 31

Also known as: 6C6-AG, BAP31, CDM, DDCH, DELXQ28, DXS1357E, MICRODELXq28

BCAP31 encodes a chaperone protein that facilitates export of secreted and transmembrane proteins from the endoplasmic reticulum and plays a role in mitochondrial respiratory chain assembly. Mutations cause X-linked recessive deafness, dystonia, and cerebral hypomyelination, affecting the auditory, motor, and central nervous systems. The gene shows moderate constraint against loss-of-function variants (LOEUF 0.65), and microdeletions involving BCAP31 are associated with contiguous ABCD1/DXS1375E deletion syndrome presenting in the neonatal period.

ResearchSummary from RefSeq, OMIM, UniProt
LOFmechanismLOEUF 0.65
Clinical SummaryBCAP31
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Gene-Disease Validity (ClinGen)
severe motor and intellectual disabilities-sensorineural deafness-dystonia syndrome · XLDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Constrained for loss-of-function variants (OE-LoF 0.21) despite low pLI — interpret in context.
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ClinVar Variants
118 unique Pathogenic / Likely Pathogenic· 78 VUS of 300 total submissions
Some data sources returned errors (1)

omim: Error: OMIM fetch failed: 429

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.65LOEUF
pLI 0.434
Z-score 2.29
OE 0.21 (0.080.65)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
1.30Z-score
OE missense 0.67 (0.560.80)
82 obs / 122.5 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.21 (0.080.65)
00.351.4
Missense OE0.67 (0.560.80)
00.61.4
Synonymous OE0.98
01.21.6
LoF obs/exp: 2 / 9.7Missense obs/exp: 82 / 122.5Syn Z: 0.14
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveBCAP31-related deafness, dystonia, and central hypomyelination with disorganization of the Golgi apparatusLOFXLR
DN
0.7326th %ile
GOF
0.5857th %ile
LOF
0.3355th %ile

The highest-scoring mechanism for this gene is dominant-negative.

DNprediction above median

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

300 submitted variants in ClinVar

Classification Summary

Pathogenic111
Likely Pathogenic7
VUS78
Likely Benign69
Benign24
Conflicting11
111
Pathogenic
7
Likely Pathogenic
78
VUS
69
Likely Benign
24
Benign
11
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
8
0
103
0
111
Likely Pathogenic
3
1
3
0
7
VUS
2
50
25
1
78
Likely Benign
0
6
36
27
69
Benign
2
1
19
2
24
Conflicting
11
Total155818630300

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

BCAP31 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →
Clinical Literature
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