MSTO1

Chr 1ADAR

misato mitochondrial distribution and morphology regulator 1

Also known as: LST005, MMYAT, MST

NCBI Gene: 55154 ENSG00000125459 UniProt: Q9BUK6 OMIM: 617619

The MSTO1 protein regulates mitochondrial distribution and morphology and is required for mitochondrial fusion and network formation. Mutations cause myopathy and ataxia affecting muscle and cerebellar systems, with both autosomal dominant and autosomal recessive inheritance patterns reported. The gene shows minimal constraint against loss-of-function variants (LOEUF 1.076), indicating tolerance to heterozygous loss.

OMIM ResearchSummary from RefSeq, OMIM, UniProt

Involved in mitochondrion distribution; mitochondrion organization; and positive regulation of mitochondrial fusion. Located in mitochondrial outer membrane. Is active in cytosol. [provided by Alliance of Genome Resources, Jul 2025]

OMIM ResearchGenerating clinical summary…

AD/ARLOEUF 1.081 OMIM phenotype

Clinical Summary— MSTO1

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Gene-Disease Validity (ClinGen)

mitochondrial disease · ARDefinitive

Definitive — sufficient evidence for diagnostic panels

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Population Constraint (gnomAD)

Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.

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ClinVar Variants

11 unique Pathogenic / Likely Pathogenic· 119 VUS of 188 total submissions

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Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?

1.08LOEUF

pLI 0.000

Z-score 1.27

OE 0.72 (0.49–1.08)

Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?

-0.02Z-score

OE missense 1.00 (0.91–1.11)

262 obs / 261.0 exp

Tolerant

Tolerant to missense variation

Observed / Expected Ratios?

LoF OE?0.72 (0.49–1.08)

0≤0.351.4

Missense OE?1.00 (0.91–1.11)

0≤0.61.4

Synonymous OE?1.05

0≤1.21.6

LoF obs/exp: 17 / 23.7Missense obs/exp: 262 / 261.0Syn Z: -0.45

ClinVar Variant Classifications

188 submitted variants in ClinVar

ClinVar

Classification Summary

Pathogenic4

Likely Pathogenic7

VUS119

Likely Benign44

Benign7

Conflicting5

Pathogenic

Likely Pathogenic

119

VUS

Likely Benign

Benign

Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

Classification	LoF	Missense + Inframe	Non-coding	Synonymous	Total
Pathogenic	2	0	2	0	4
Likely Pathogenic	2	3	2	0	7
VUS	4	107	7	1	119
Likely Benign	0	11	13	20	44
Benign	0	0	6	1	7
Conflicting	—				5
Total	8	121	30	22	186

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

9 pathogenic / likely-pathogenic (of 12) ClinVar copy-number / structural variants overlap MSTO1 — these span large chromosomal regions, not the gene specifically, and are excluded from the counts above. Explore in CNV tools →