GPC5 encodes a cell surface proteoglycan that bears heparan sulfate and is anchored to the membrane via a glycosyl phosphatidylinositol linkage. Mutations cause Simpson-Golabi-Behmel syndrome type 2, an X-linked overgrowth disorder characterized by pre- and postnatal overgrowth, intellectual disability, and distinctive facial features. The gene shows extreme intolerance to loss-of-function variants, indicating that complete loss of protein function is likely incompatible with normal development.

OMIMResearchSummary from RefSeq, UniProt
DNmechanismLOEUF 1.08
Clinical SummaryGPC5
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
83 unique Pathogenic / Likely Pathogenic· 118 VUS of 236 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.08LOEUF
pLI 0.000
Z-score 1.24
OE 0.73 (0.501.08)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
-0.59Z-score
OE missense 1.09 (1.001.19)
351 obs / 321.3 exp
Tolerant

Tolerant to missense variation

Observed / Expected Ratios
LoF OE0.73 (0.501.08)
00.351.4
Missense OE1.09 (1.001.19)
00.61.4
Synonymous OE1.17
01.21.6
LoF obs/exp: 18 / 24.6Missense obs/exp: 351 / 321.3Syn Z: -1.44
DN
0.6936th %ile
GOF
0.6053th %ile
LOF
0.2678th %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

236 submitted variants in ClinVar

Classification Summary

Pathogenic80
Likely Pathogenic3
VUS118
Likely Benign20
Benign5
Conflicting2
80
Pathogenic
3
Likely Pathogenic
118
VUS
20
Likely Benign
5
Benign
2
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
80
0
80
Likely Pathogenic
0
0
3
0
3
VUS
0
94
24
0
118
Likely Benign
0
7
12
1
20
Benign
0
1
2
2
5
Conflicting
2
Total01021213228

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

View in ClinVar →

Protein Context — Lollipop Plot

GPC5 · 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.

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Clinical Literature
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