PLEKHG4B

Chr 5

pleckstrin homology and RhoGEF domain containing G4B

Also known as: ARHGEF48

The protein functions as a guanine nucleotide exchange factor that specifically activates CDC42 by exchanging GDP for GTP, regulating actin cytoskeletal remodeling during cell-cell junction formation. Mutations cause autosomal recessive neurodevelopmental disorders with intellectual disability, seizures, and motor abnormalities. The gene shows minimal constraint against loss-of-function variants, consistent with the recessive inheritance pattern observed in affected individuals.

OMIMResearchSummary from RefSeq, UniProt
GOFmechanismLOEUF 1.22
Clinical SummaryPLEKHG4B
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.22LOEUF
pLI 0.000
Z-score 0.22
OE 0.97 (0.771.22)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
-0.27Z-score
OE missense 1.03 (0.971.09)
762 obs / 741.3 exp
Tolerant

Tolerant to missense variation

Observed / Expected Ratios
LoF OE0.97 (0.771.22)
00.351.4
Missense OE1.03 (0.971.09)
00.61.4
Synonymous OE1.04
01.21.6
LoF obs/exp: 50 / 51.7Missense obs/exp: 762 / 741.3Syn Z: -0.60
DN
0.5280th %ile
GOF
0.7028th %ile
LOF
0.48top 25%

The highest-scoring mechanism for this gene is gain-of-function.

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.

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

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

PLEKHG4B · 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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