MT-TI

Chr MT

tRNA-Ile

Also known as: MTTI

NCBI Gene: 4565 ENSG00000210100 OMIM: 590045

This gene encodes mitochondrial tRNA for isoleucine, which is essential for protein synthesis within mitochondria and proper functioning of the electron transport chain. Mutations cause cardiomyopathy and progressive external ophthalmoplegia, with clinical severity depending on the degree of heteroplasmy in affected tissues. Inheritance follows a maternal pattern since the gene resides in the mitochondrial genome.

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-TI

Authoritative clinical overview · Recommended first read

Open GeneReview ↗

Nuclear-gene analyses omitted

MT-TI 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-TI

Live table ↗

Variant	Disease	Status	GenBank seqs
m.4263A>G	Maternally inherited essential hypertension	Reported	3
m.4267A>G	MM / CPEO	Reported	0
m.4268T>C	Maternally inherited hearing loss	Reported	0
m.4269A>G	FICP	Uncertain significance · reported	1
m.4271G>C	Suspected mitochondrial disease	Reported	0
m.4274T>C	CPEO / Motor Neuron Disease	Reported	0
m.4275G>A	CPEO Plus	Reported	0
m.4277T>C	HCM / Poss. hypertension factor	Reported	23
m.4279A>G	Myoclonic epilepsy	Reported	0
m.4281A>G	Recurrent Myoglobinuria	Reported	1
m.4282G>A	CPEO Plus	Reported	0
m.4284G>A	Varied familial presentation / spastic paraparesis / MERRF-like	Uncertain significance · reported	2
m.4285T>C	CPEO	Reported	0
m.4289T>C	Retinopathy+diabetes+dysphagia+cerebral atrophy	Reported	0
m.4290T>C	Progressive Encephalopathy / PEO,myopathy	Reported	0
m.4291T>C	Hypomagnesemic Metabolic Syndrome / Gitelman-like syndrome	Uncertain significance · reported	0
m.4295A>G	MHCM / Maternally inherited hypertension / Maternally inherited deafness	Uncertain significance · reported	114
m.4296G>A	Leigh Syndrome	Uncertain significance · reported	0
m.4298G>A	CPEO / MS	Uncertain significance · confirmed	0
m.4300A>G	MICM	Likely pathogenic · confirmed	0
m.4301A>T	Patient with MELAS	Reported	1
m.4302A>G	CPEO	Reported	0
m.4305A>G	Suspected mitochondrial disease	Reported	0
m.4308G>A	CPEO	Uncertain significance · confirmed	0
m.4309G>A	CPEO	Reported	0
m.4314T>C	Poss. hypertension factor	Reported	49
m.4316A>G	HCM with hearing loss / poss. hypertension factor	Reported	36
m.4317A>G	FICP / poss. Hypertension / DEAF factor	Reported	52
m.4317A>-	Ptosis, deafness, stroke-like episodes	Reported	18
m.4320C>T	Mitochondrial Encephalocardiomyopathy	Reported	10
m.4322C>CC	Idiopathic Dilated Cardiomopathy	Reported	3
m.4322C>-	mtDNA deletion and depletion with dilated cardiomyopathy	Reported	2
m.4327T>C	Ataxia+, with RRF and COX deficiency	Reported	0