[Phenotypic variants of A3243G mitochondrial DNA mutation in a Hungarian family]

Area of Science:

• Genetics
• Neurology
• Pediatrics

Background:

• Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is a multisystem disorder typically presenting in childhood.
• It is inherited through mitochondrial DNA and characterized by specific neurological and metabolic abnormalities.

Observation:

• The first Hungarian pediatric case of MELAS is described in a 6-year-old girl with recurrent vomiting, visual loss, and stroke-like episodes.
• Clinical symptoms progressively affected motor abilities and mental development.
• Molecular analysis confirmed the heteroplasmic A3243G transition in the mitochondrial DNA.

Findings:

• The proband's mother, exhibiting bilateral hypacusis, carried the mutation at 20% heteroplasmy.
• An asymptomatic maternal aunt had the mutation at 10% heteroplasmy.
• This specific mutation pattern and associated hypacusis in the mother may distinguish this pedigree.

Implications:

• This case expands the understanding of MELAS presentation and genetic variability in a Hungarian population.
• The findings highlight the potential association between the A3243G mutation and bilateral hypacusis, suggesting a broader clinical spectrum.
• Further research can elucidate genotype-phenotype correlations and diagnostic criteria for MELAS syndrome.