BLTP1

Chr 4AR

bridge-like lipid transfer protein family member 1

Also known as: ALKKUCS, FSA, KIAA1109, Tweek

The encoded protein functions as a bridge-like lipid transfer protein that transports phospholipids between the endoplasmic reticulum and target membranes, and is involved in endosomal trafficking, actin cytoskeleton dynamics, and cilia structure. Biallelic mutations cause Alkuraya-Kucinskas syndrome, inherited in an autosomal recessive pattern. The gene is highly constrained against loss-of-function variants (LOEUF 0.41), indicating intolerance to protein-disrupting mutations.

Summary from RefSeq, OMIM, UniProt
Research Assistant →

Primary Disease Associations & Inheritance

Alkuraya-Kucinskas syndromeMIM #617822
AR
0
Active trials
3
Pubs (1 yr)
4
P/LP submissions
0%
P/LP missense
0.41
LOEUF
Mechanism
Clinical SummaryBLTP1
Population Constraint (gnomAD)
Constrained for loss-of-function variants (OE-LoF 0.34) despite low pLI — interpret in context.
📋
ClinVar Variants
4 unique Pathogenic / Likely Pathogenic· 115 VUS of 200 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Missense constrained — critical functional residues
LoF Constraint
0.41LOEUF
pLI 0.000
Z-score 9.56
OE 0.34 (0.290.41)
Moderately constrained

More LoF-intolerant than ~75% of genes

Missense Constraint
6.00Z-score
OE missense 0.67 (0.640.69)
1707 obs / 2561.8 exp
Constrained

Extremely missense-constrained (top ~0.01%)

Observed / Expected Ratios
LoF OE0.34 (0.290.41)
00.351.4
Missense OE0.67 (0.640.69)
00.61.4
Synonymous OE0.94
01.21.6
LoF obs/exp: 84 / 245.8Missense obs/exp: 1707 / 2561.8Syn Z: 1.47

ClinVar Variant Classifications

200 submitted variants in ClinVar

Classification Summary

Pathogenic2
Likely Pathogenic2
VUS115
Likely Benign6
2
Pathogenic
2
Likely Pathogenic
115
VUS
6
Likely Benign

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
1
0
1
0
2
Likely Pathogenic
1
0
1
0
2
VUS
0
113
2
0
115
Likely Benign
0
5
1
0
6
Benign
0
0
0
0
0
Total211850125

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

View in ClinVar →

Protein Context — Lollipop Plot

BLTP1 · protein map & ClinVar variants

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

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