MS4A18

Chr 11

membrane spanning 4-domains A18

NCBI Gene: 728588 ENSG00000214782 UniProt: Q3C1V0

The protein is predicted to function in cell surface receptor signaling at the plasma membrane. Mutations cause an unspecified disorder with autosomal recessive inheritance. The gene shows moderate tolerance to loss-of-function variants based on population genetics data.

ResearchSummary from RefSeq

Predicted to be involved in cell surface receptor signaling pathway. Predicted to be located in membrane. Predicted to be active in plasma membrane. [provided by Alliance of Genome Resources, Jul 2025]

ResearchGenerating clinical summary…

Active trials

Pubs (1 yr)

—

P/LP submissions

—

P/LP missense

1.24

LOEUF

Multiple*

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?

1.24LOEUF

pLI 0.000

Z-score 0.90

OE 0.75 (0.47–1.24)

Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?

1.49Z-score

OE missense 0.68 (0.59–0.80)

118 obs / 173.0 exp

Tolerant

Mild missense constraint

Observed / Expected Ratios?

LoF OE?0.75 (0.47–1.24)

0≤0.351.4

Missense OE?0.68 (0.59–0.80)

0≤0.61.4

Synonymous OE?0.79

0≤1.21.6

LoF obs/exp: 11 / 14.7Missense obs/exp: 118 / 173.0Syn Z: 1.37

Background carrier burden — how many people carry a rare variant somewhere in MS4A18?

gnomAD v4 · ~276k individuals · PASS only

Rare means allele frequency under

Rare missense

1 in 63

350 rare PASS variants

Rare truncating (LoF)

1 in 220

82 rare PASS variants

Rare synonymous (reference)

1 in 160

148 rare PASS variants

Rare missense and truncating variants are carried at similar rates in MS4A18; this gene does not show strong loss-of-function constraint by this measure. 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)	~159k	1 in 96	1 in 330
South Asian	~31k	1 in 130	1 in 310
African / African American	~21k	1 in 69	1 in 530
Admixed American	~17k	1 in 64	1 in 430
European (Finnish)	~17k	1 in 580	1 in 2,800
East Asian	~16k	1 in 120	1 in 720
Remaining (unassigned)	~15k	1 in 59	1 in 310
Ashkenazi Jewish	~10k	1 in 400	≈ 1 in 5,000
Middle Eastern	~2,041	1 in 93	≈ 1 in 1,000

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): 0 of 6 coding exons well covered in gnomAD exomes; exons 2, 3, 4, 5, 6, 7 poorly covered. Genomes: all 6.? see exons ↓