FABP2

Chr 4

fatty acid binding protein 2

Also known as: FABPI, I-FABP

NCBI Gene: 2169 ENSG00000145384 UniProt: P12104

The protein encoded by FABP2 is an intracellular fatty acid-binding protein that transports long-chain fatty acids and their acyl-CoA esters within cells, participates in triglyceride-rich lipoprotein synthesis, and functions as a lipid sensor for energy homeostasis. This gene is not well-established as a cause of pediatric neurogenetic disease, as it shows tolerance to loss-of-function variants (pLI = 0.005, LOEUF = 1.5) and primarily functions in intestinal fatty acid metabolism rather than neurological pathways.

ResearchSummary from RefSeq, UniProt

The protein encoded by this gene is an intracellular fatty acid-binding protein that participates in the uptake, intracellular metabolism, and transport of long-chain fatty acids. The encoded protein is also involved in the modulation of cell growth and proliferation. This protein binds saturated long-chain fatty acids with high affinity, and may act as a lipid sensor to maintain energy homeostasis. [provided by RefSeq, Aug 2017]

ResearchGenerating clinical summary…

Active trials

Pubs (1 yr)

—

P/LP submissions

—

P/LP missense

1.50

LOEUF

Mechanism· predicted

Some data sources returned errors (1)

omim: Error: OMIM fetch failed: 429

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?

1.50LOEUF

pLI 0.005

Z-score 0.73

OE 0.68 (0.33–1.50)

Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?

0.71Z-score

OE missense 0.76 (0.61–0.95)

52 obs / 68.6 exp

Tolerant

Mild missense constraint

Observed / Expected Ratios?

LoF OE?0.68 (0.33–1.50)

0≤0.351.4

Missense OE?0.76 (0.61–0.95)

0≤0.61.4

Synonymous OE?0.97

0≤1.21.6

LoF obs/exp: 4 / 5.9Missense obs/exp: 52 / 68.6Syn Z: 0.13

Background carrier burden — how many people carry a rare variant somewhere in FABP2?

gnomAD v4 · ~731k individuals · PASS only

Rare means allele frequency under

Rare missense

1 in 490

153 rare PASS variants

Rare truncating (LoF)

1 in 4,300

31 rare PASS variants

Rare synonymous (reference)

1 in 1,600

47 rare PASS variants

Truncating variants are far rarer here than missense — that gap, in human units, is what constraint means for FABP2. A background rate for each class, not the frequency of any particular variant; thin-coverage exons undercount.

By genetic ancestry · 9 gnomAD groups · rare = under 0.1% in that group

Group	People	Missense	Truncating
European (non-Finnish)	~556k	1 in 710	1 in 5,200
South Asian	~43k	1 in 320	1 in 1,900
Remaining (unassigned)	~30k	1 in 270	1 in 2,900
European (Finnish)	~27k	1 in 850	1 in 2,900
Admixed American	~22k	1 in 720	none seen
African / African American	~21k	1 in 440	1 in 1,600
East Asian	~20k	1 in 470	1 in 1,300
Ashkenazi Jewish	~13k	1 in 680	none seen
Middle Eastern	~2,884	≈ 1 in 660	none seen

Each group is summed over the variants that are rare in that group. Grey ≈ figures rest on fewer than five expected carriers — too few to distinguish groups. Differences mostly reflect how many people were sampled and how much variation each ancestry carries, not disease risk.

Exome coverage (gnomAD): 2 of 4 coding exons well covered in gnomAD exomes; exons 3, 4 marginal. Genomes: 3 of 4 (exon 3 below).? see exons ↓