MT-TW

Chr MT

tRNA-Trp

Also known as: MTTW

NCBI Gene: 4578 ENSG00000210117 OMIM: 590095

This gene encodes mitochondrial tRNA for tryptophan, which is essential for mitochondrial protein synthesis and oxidative phosphorylation. Mutations cause encephalomyopathy and Leigh syndrome through disruption of mitochondrial energy production. Inheritance is maternal, and clinical severity depends on the degree of heteroplasmy in affected tissues.

GeneReviews OMIM ResearchSummary from Curated mito context

GeneReviews OMIM ResearchGenerating clinical summary…

Clinical highlights

Gene–disease validity (ClinGen)

Active trials

Pubs (1 yr)

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P/LP submissions

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P/LP missense

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LOEUF

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Mechanism

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GeneReview available — MT-TW

Authoritative clinical overview · Recommended first read

Open GeneReview ↗

Nuclear-gene analyses omitted

MT-TW is a mitochondrial tRNA gene. gnomAD constraint, carrier burden and exome coverage, the ClinVar type breakdown, the protein lollipop, AlphaFold and transcript-architecture views are built for nuclear genes and are not shown. Population data for mtDNA variants (gnomAD v3.1, homoplasmy and heteroplasmy) is on each variant page.

Where it sits in the mitochondrial genome

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proteinrRNAtRNAouter ring H-strand · inner L-strandMITOMAP confirmedreported (as of 2026-10-07)

37 genes from Ensembl (rCRS numbering, matched to MITOMAP’s Gene Loci); landmarks and disease alleles from MITOMAP (CC BY 3.0). Circular layout after MitoWheel.

ClinVar Variant Classifications

0 submitted variants in ClinVar

ClinVar

MITOMAP Disease Variants — MT-TW

Live table ↗

Variant	Disease	Status	GenBank seqs
m.5512A>G	Maternally inherited hypertension	Reported	6
m.5513G>A	Mitochondrial encephalomyopathy with RP	Reported	1
m.5514A>G	Neonatal onset mito disease	Reported	49
m.5521G>A	Mitochondrial myopathy	Likely pathogenic · confirmed	0
m.5522G>A	Mitochondrial myopathy	Reported	0
m.5523T>G	Leigh Syndrome	Uncertain significance · reported	0
m.5532G>A	Gastrointestinal Syndrome	Uncertain significance · reported	1
m.5537A>AT	Leigh Syndrome	Likely pathogenic · confirmed	0
m.5538G>A	Encephalomyopathy	Uncertain significance · reported	0
m.5540G>A	Encephalomyopathy / DEAF	Uncertain significance · reported	0
m.5541C>T	MELAS+stroke-like episodes and cortical blindness+MRI shows occipital lobe infarct	Reported	0
m.5543T>C	Mitochondrial myopathy	Uncertain significance · reported	0
m.5545C>T	HCM severe multisystem disorder	Uncertain significance · reported	0
m.5549G>A	DEMCHO / mitochondrial encephalomyopathy	Uncertain significance · reported	0
m.5556G>C	Mito encephalomyopathy	Reported	0
m.5556G>A	Combined OXPHOS defects	Likely pathogenic · confirmed	0
m.5558A>G	Reported in tic disorder patient / NSSNHL	Uncertain significance · reported	136
m.5559A>G	Leigh Syndrome	Reported	0
m.5567T>C	Myopathy	Reported	59
m.5568A>G	DEAF	Reported	21