FAM171B

Chr 2

family with sequence similarity 171 member B

Also known as: KIAA1946

The FAM171B protein is predicted to localize to cellular membranes and function at synapses. Mutations cause autosomal recessive intellectual disability with seizures and spasticity, typically presenting in early childhood. This gene shows significant constraint against loss-of-function variants (LOEUF 0.408), suggesting intolerance to protein-disrupting mutations.

OMIMResearchSummary from RefSeq
LOEUF 0.41
Clinical SummaryFAM171B
Population Constraint (gnomAD)
Constrained for loss-of-function variants (OE-LoF 0.22) despite low pLI — interpret in context.
📋
ClinVar Variants
26 unique Pathogenic / Likely Pathogenic· 88 VUS of 131 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Moderate LoF intolerance
LoF Constraint
0.41LOEUF
pLI 0.485
Z-score 4.12
OE 0.22 (0.120.41)
Moderately constrained

More LoF-intolerant than ~75% of genes

Missense Constraint
1.51Z-score
OE missense 0.80 (0.730.87)
344 obs / 432.1 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.22 (0.120.41)
00.351.4
Missense OE0.80 (0.730.87)
00.61.4
Synonymous OE0.96
01.21.6
LoF obs/exp: 7 / 32.3Missense obs/exp: 344 / 432.1Syn Z: 0.40

ClinVar Variant Classifications

131 submitted variants in ClinVar

Classification Summary

Pathogenic26
VUS88
Likely Benign4
Benign6
26
Pathogenic
88
VUS
4
Likely Benign
6
Benign

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
26
0
26
Likely Pathogenic
0
0
0
0
0
VUS
0
84
4
0
88
Likely Benign
0
4
0
0
4
Benign
0
2
0
4
6
Total090304124

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

View in ClinVar →

Protein Context — Lollipop Plot

FAM171B · 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
Open Research Assistant →
Key Publications
Landmark & review papers · by relevance
PubMed
Top 1 results · since 2015Search PubMed ↗
Recent Gene-Specific Literature
Gene in title · MEDLINE · newest first
Europe PMC