Clinical features of mtDNA A3243G mutation in adult patients / 中华神经科杂志

ABSTRACT

Objective To analysis the clinical manifestations of mtDNA A3243G mutation in adulthood.Methods The clinical features were investigated in 36 cases (28 patients from 5 families with the mutation and 8 sporadic cases),in whom mtDNA A3243G mutation was confirmed genetically in 23 cases (15 cases from 5 mutation families and 8 sporadic cases).Cranium radiology was performed in 14 cases.Muscal biopsies were performed in l0 cases.Results Among 28 cases in the 5 family,there were 9 cases (32.1%) with stroke like episodes,17 cases (60.7%) with diabetic mellitus and 16 cases (57.1%) with deafness.Such symptoms usually combined with each other and rarely existed alone. Cardiomyopathy and renal failure were uncommon.In the 23 cases with mtDNA A3243G mutation,14 cases (61.0%) had mitochondria] myopathy,encephalopathy,lactic acidosis,and stroke-like episodes (MELAS),mostly presenting cognitive abnormalities,dysarthria or aphasia and headache,3 cases (13.0%) were asymptomatic carriers,2 cases (8.7%) had autonomic dysfunction,2 cases (8.7%) had diabetic mellitus with or without nerve deafness,1 case (4.3%) had diabetic mellitus with infertilitas and cardiomyopathy,respectively.Cranial radiological images revealed the changes more commonly in the temporal and occipital lobes and less frequently in the frontal lobes.Ragged red fibers were confirmed in 9 of 10 cases with muscle biopsies.The proportion of mutant mtDNA A3243C was not significantly different between MEALS (28.75%?13.69%) and non-MELAS (25.08%?11.54%).Conclusions mtDNA A3243G mutation mainly results in the lesions in the central nerve system,pancreatic island and acoustic nerve in adulthood.Heart and kidney are less frequently involved.Cognitive abnormalities,aphasia and headache are the major symptoms of adult MELAS.Families have with more than 1 patient with diabetic mellitus and deafness,indicating that the mutation is other than MELAS mutation.We should pay more attention to the non-MELAS symptoms in the families with mtDNA A3243G mutation.