HEPACAM

Chr 11ARAD

hepatic and glial cell adhesion molecule

Also known as: GlialCAM, MLC2A, MLC2B

HEPACAM encodes a membrane protein that regulates cell motility and cell-matrix interactions, and in glia it targets the chloride channel CLCN2 to astrocytic processes where it regulates chloride flux involved in neuronal excitability. Mutations cause megalencephalic leukoencephalopathy with subcortical cysts, which can present as either a severe progressive form (type 2A) or a milder remitting form (type 2B) that may occur with or without intellectual disability. The gene shows high constraint against loss-of-function variants and follows both autosomal recessive and autosomal dominant inheritance patterns.

OMIMResearchSummary from RefSeq, OMIM, UniProt
MultiplemechanismAR/ADLOEUF 0.412 OMIM phenotypes
Clinical SummaryHEPACAM
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Gene-Disease Validity (ClinGen)
megalencephalic leukoencephalopathy with subcortical cysts 2B, remitting, with or without intellectual disability · ADDefinitive

Definitive — sufficient evidence for diagnostic panels

2 total gene-disease associations curated

Population Constraint (gnomAD)
Moderately constrained gene (pLI 0.87) — some intolerance to loss-of-function variants.
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ClinVar Variants
48 unique Pathogenic / Likely Pathogenic· 88 VUS of 192 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Moderate LoF intolerance
LoF Constraint
0.41LOEUF
pLI 0.868
Z-score 3.16
OE 0.13 (0.050.41)
Moderately constrained

More LoF-intolerant than ~75% of genes

Missense Constraint
1.59Z-score
OE missense 0.69 (0.600.79)
145 obs / 209.9 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.13 (0.050.41)
00.351.4
Missense OE0.69 (0.600.79)
00.61.4
Synonymous OE0.97
01.21.6
LoF obs/exp: 2 / 15.4Missense obs/exp: 145 / 209.9Syn Z: 0.19
DN
0.5869th %ile
GOF
0.6931th %ile
LOF
0.55top 25%

This gene has evidence for multiple mechanisms of pathogenicity (loss-of-function and gain-of-function). The Badonyi & Marsh model scores gain-of-function highest among its predictions, but genomic evidence (constraint, ClinVar variant spectrum, and literature) most strongly supports loss-of-function (haploinsufficiency). Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

LOF1 literature citation · LOEUF 0.41
GOFprediction 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.

Literature Evidence

LOFWe therefore suggest that haploinsufficiency of HEPACAM, a gene previously associated with the features of MLC2 and located on the overlapping deletion region between the two patients, might be related to the observed white matter abnormalities.PMID:26193381

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.

ClinVar Variant Classifications

192 submitted variants in ClinVar

Classification Summary

Pathogenic41
Likely Pathogenic7
VUS88
Likely Benign34
Benign13
Conflicting6
41
Pathogenic
7
Likely Pathogenic
88
VUS
34
Likely Benign
13
Benign
6
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
2
4
35
0
41
Likely Pathogenic
2
5
0
0
7
VUS
0
59
29
0
88
Likely Benign
0
7
13
14
34
Benign
0
3
7
3
13
Conflicting
6
Total4788417189

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

View in ClinVar →

Protein Context — Lollipop Plot

HEPACAM · 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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