MIX23

Chr 3

mitochondrial matrix import factor 23

Also known as: CCDC58

NCBI Gene: 131076 ENSG00000160124 UniProt: Q4VC31 OMIM: 620713

MIX23 encodes a mitochondrial protein with unknown specific function. Mutations cause autosomal recessive developmental disorders, though the clinical phenotype remains poorly characterized. This gene shows low constraint against loss-of-function variants, suggesting haploinsufficiency may not be the primary disease mechanism.

OMIM ResearchSummary from RefSeq

Located in mitochondrion. [provided by Alliance of Genome Resources, Jul 2025]

OMIM ResearchGenerating clinical summary…

Active trials

Pubs (1 yr)

—

P/LP submissions

—

P/LP missense

1.14

LOEUF

Mechanism· predicted

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?

1.14LOEUF

pLI 0.004

Z-score 1.29

OE 0.54 (0.28–1.14)

Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?

0.90Z-score

OE missense 0.71 (0.57–0.89)

53 obs / 74.8 exp

Tolerant

Mild missense constraint

Observed / Expected Ratios?

LoF OE?0.54 (0.28–1.14)

0≤0.351.4

Missense OE?0.71 (0.57–0.89)

0≤0.61.4

Synonymous OE?1.13

0≤1.21.6

LoF obs/exp: 5 / 9.2Missense obs/exp: 53 / 74.8Syn Z: -0.54

Background carrier burden — how many people carry a rare variant somewhere in MIX23?

gnomAD v4 · ~731k individuals · PASS only

Rare means allele frequency under

Rare missense

1 in 590

165 rare PASS variants

Rare truncating (LoF)

1 in 620

41 rare PASS variants

Rare synonymous (reference)

1 in 1,100

70 rare PASS variants

Rare missense and truncating variants are carried at similar rates in MIX23; 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)	~556k	1 in 690	1 in 2,800
South Asian	~43k	1 in 240	none seen
Remaining (unassigned)	~30k	1 in 440	1 in 1,200
European (Finnish)	~27k	1 in 3,300	≈ 1 in 27,000
Admixed American	~22k	1 in 540	1 in 1,100
African / African American	~21k	1 in 500	1 in 2,200
East Asian	~20k	1 in 550	≈ 1 in 9,800
Ashkenazi Jewish	~13k	none seen	≈ 1 in 13,000
Middle Eastern	~2,884	1 in 400	≈ 1 in 660

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 5 marginal. Genomes: 4 of 5 (exon 5 below).? see exons ↓