CIMIP2B

Chr 9

ciliary microtubule inner protein 2B

Also known as: FAM166B

NCBI Gene: 730112 ENSG00000215187 UniProt: A8MTA8 OMIM: 621690

The protein is a microtubule inner protein component of dynein-decorated doublet microtubules in cilia axonemes that is required for motile cilia beating. Mutations cause primary ciliary dyskinesia, which affects the respiratory tract, fertility, and can involve organ laterality defects. Primary ciliary dyskinesia follows autosomal recessive inheritance.

OMIM ResearchSummary from RefSeq, UniProt

Predicted to be involved in flagellated sperm motility. Located in axonemal microtubule. [provided by Alliance of Genome Resources, Jul 2025]

OMIM ResearchGenerating clinical summary…

Active trials

Pubs (1 yr)

—

P/LP submissions

—

P/LP missense

1.75

LOEUF

—

Mechanism

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?

1.75LOEUF

pLI 0.000

Z-score -0.45

OE 1.15 (0.74–1.75)

Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?

0.04Z-score

OE missense 0.99 (0.86–1.14)

145 obs / 146.3 exp

Tolerant

Mild missense constraint

Observed / Expected Ratios?

LoF OE?1.15 (0.74–1.75)

0≤0.351.4

Missense OE?0.99 (0.86–1.14)

0≤0.61.4

Synonymous OE?0.88

0≤1.21.6

LoF obs/exp: 13 / 11.3Missense obs/exp: 145 / 146.3Syn Z: 0.68

Background carrier burden — how many people carry a rare variant somewhere in CIMIP2B?

gnomAD v4 · ~731k individuals · PASS only

Rare means allele frequency under

Rare missense

1 in 110

410 rare PASS variants

Rare truncating (LoF)

1 in 570

117 rare PASS variants

Rare synonymous (reference)

1 in 170

150 rare PASS variants

Truncating variants are far rarer here than missense — that gap, in human units, is what constraint means for CIMIP2B. 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 170	1 in 450
South Asian	~43k	1 in 120	1 in 300
Remaining (unassigned)	~30k	1 in 110	1 in 420
European (Finnish)	~27k	1 in 400	1 in 1,200
Admixed American	~22k	1 in 93	1 in 310
African / African American	~21k	1 in 140	1 in 260
East Asian	~20k	1 in 130	1 in 300
Ashkenazi Jewish	~13k	1 in 710	≈ 1 in 5,900
Middle Eastern	~2,884	1 in 100	1 in 450

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 6 coding exons well covered in gnomAD exomes and genomes.? see exons ↓