CATSPERZ

Chr 11

catsper channel auxiliary subunit zeta

Also known as: C11orf20, TEX40

NCBI Gene: 25858 ENSG00000219435 UniProt: Q9NTU4 OMIM: 617511

CATSPERZ encodes an auxiliary component of the CatSper complex that is required for sperm hyperactivation and proper distribution of CatSper channels along the flagellum, which are essential for sperm motility and fertilization. Mutations cause autosomal recessive male infertility due to defective sperm function. This gene shows low constraint to loss-of-function variation in the general population.

OMIM ResearchSummary from RefSeq, UniProt

Predicted to be involved in flagellated sperm motility; male meiotic nuclear division; and sperm capacitation. Located in cytoplasm; sperm midpiece; and sperm principal piece. [provided by Alliance of Genome Resources, Jun 2026]

OMIM ResearchGenerating clinical summary…

Active trials

Pubs (1 yr)

—

P/LP submissions

—

P/LP missense

1.02

LOEUF

Multiple*

Mechanism· predicted

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?

1.02LOEUF

pLI 0.020

Z-score 1.54

OE 0.45 (0.22–1.02)

Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?

0.52Z-score

OE missense 0.86 (0.73–1.02)

93 obs / 108.1 exp

Tolerant

Mild missense constraint

Observed / Expected Ratios?

LoF OE?0.45 (0.22–1.02)

0≤0.351.4

Missense OE?0.86 (0.73–1.02)

0≤0.61.4

Synonymous OE?0.67

0≤1.21.6

LoF obs/exp: 4 / 9.0Missense obs/exp: 93 / 108.1Syn Z: 1.77

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

gnomAD v4 · ~731k individuals · PASS only

Rare means allele frequency under

Rare missense

1 in 320

258 rare PASS variants

Rare truncating (LoF)

1 in 4,000

52 rare PASS variants

Rare synonymous (reference)

1 in 900

128 rare PASS variants

Truncating variants are far rarer here than missense — that gap, in human units, is what constraint means for CATSPERZ. 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 410	1 in 4,600
South Asian	~43k	1 in 400	1 in 5,000
Remaining (unassigned)	~30k	1 in 240	1 in 4,800
European (Finnish)	~27k	1 in 2,300	1 in 2,500
Admixed American	~22k	1 in 170	1 in 1,100
African / African American	~21k	1 in 160	1 in 2,600
East Asian	~20k	1 in 170	1 in 2,100
Ashkenazi Jewish	~13k	1 in 1,000	≈ 1 in 10,000
Middle Eastern	~2,884	1 in 180	≈ 1 in 960

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): 4 of 5 coding exons well covered in gnomAD exomes; exon 1 marginal. Genomes: all 5.? see exons ↓