Table 3. The mitochondrial phenotypes and clinical features reported with homozygous A467T mutations.

PHENOTYPE	CLINICAL FEATURES	REFERENCE
PEO	Progressive external ophthalmoplegia; seizures	[7]
SANDO	Sensory ataxia; dysarthria; ophthalmoparesis	[26]
Alpers Huttenlocher syndrome	Epilepsy; EPC; psychomotor regression; liver failure; neuropathy; range of onset from 1–36 years	[3, 27, 28]
Encephalopathy	Encephalopathy; stroke-like episodes; myoclonus; PEO	[3]
MEMSA	Myopathy, epilepsy, and ataxia without ophthalmoplegia.	[3]
“MNGIE-like”	Gastro-intestinal dysmotility; cachexia; PEO; ptosis; peripheral neuropathy; no leukoencephalopathy; normal plasma thymidine	[29]
Ataxia	Hypotonia, Headache, muscle weakness	[7]
Epilepsy	Ataxia, myoclonic seizures, optic atrophy, dysarthria, and developmentally delayed	[3, 7]
Epilepsy with occipital lobe predilection	SPS; CPS; sGTCS; SE Ataxia; headache; vomiting;	[30]
“Mitochondrial ataxia +” syndrome	Ataxia; migraine-like headaches; focal epilepsy; myoclonus; PEO; neuropathy	[31, 32]

Abbreviations: CPS, complex partial seizure; EPC, epilepsia partialis continua; MEMSA, Myoclonic epilepsy myopathy sensory ataxia; MINGIE, mitochondrial neurogastrointestinal encephalopathy; PEO, progressive external ophthalmoplegia; SE, status epilepticus; sGTCS, secondary generalised tonic-clonic seizures; SPS, simple partial seizure.