SLC25A32

Chr 8AR

solute carrier family 25 member 32

Also known as: GLYB, MFT, MFTC, RREI

NCBI Gene: 81034 ENSG00000164933 UniProt: Q9H2D1 OMIM: 138480

The protein facilitates flavin adenine dinucleotide (FAD) transport across the mitochondrial inner membrane, where FAD serves as a redox cofactor for fatty acid beta-oxidation, amino acid metabolism, and mitochondrial electron transport. Mutations cause autosomal recessive exercise intolerance that responds to riboflavin supplementation. The gene shows low constraint against loss-of-function variants, consistent with recessive inheritance where heterozygous carriers are typically unaffected.

OMIM ResearchSummary from RefSeq, OMIM, UniProt

This gene encodes a member of the P(I/L)W subfamily of mitochondrial carrier family transport proteins. The encoded protein transports folate across the inner mitochondrial membrane. Alternatively spliced transcript variants have been described. [provided by RefSeq, Mar 2013]

OMIM ResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

?Exercise intolerance, riboflavin-responsiveMIM #616839

UniProtNeural tube defects

Clinical highlights

Gene–disease validity (ClinGen)

Limited · exercise intolerance, riboflavin-responsive · AR · ClinGen 2026

not for standalone diagnostic reporting

Active trials

Pubs (1 yr)

—

P/LP submissions

—

P/LP missense

1.32

LOEUF

Multiple*

Mechanism· predicted

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?

1.32LOEUF

pLI 0.000

Z-score 0.59

OE 0.84 (0.56–1.32)

Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?

0.37Z-score

OE missense 0.92 (0.81–1.05)

165 obs / 178.9 exp

Tolerant

Mild missense constraint

Observed / Expected Ratios?

LoF OE?0.84 (0.56–1.32)

0≤0.351.4

Missense OE?0.92 (0.81–1.05)

0≤0.61.4

Synonymous OE?1.20

0≤1.21.6

LoF obs/exp: 14 / 16.6Missense obs/exp: 165 / 178.9Syn Z: -1.31

Background carrier burden — how many people carry a rare variant somewhere in SLC25A32?

gnomAD v4 · ~731k individuals · PASS only

Rare means allele frequency under

Rare missense

1 in 180

395 rare PASS variants

Rare truncating (LoF)

1 in 2,100

67 rare PASS variants

Rare synonymous (reference)

1 in 680

171 rare PASS variants

Truncating variants are far rarer here than missense — that gap, in human units, is what constraint means for SLC25A32. 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 210	1 in 2,100
South Asian	~43k	1 in 130	1 in 1,700
Remaining (unassigned)	~30k	1 in 120	1 in 2,000
European (Finnish)	~27k	1 in 580	1 in 5,300
Admixed American	~22k	1 in 190	≈ 1 in 5,600
African / African American	~21k	1 in 110	1 in 1,300
East Asian	~20k	1 in 210	≈ 1 in 20,000
Ashkenazi Jewish	~13k	1 in 870	≈ 1 in 12,000
Middle Eastern	~2,884	1 in 180	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): All 7 coding exons well covered in gnomAD exomes and genomes.? see exons ↓