Maternally inherited deafness and unusual phenotypic manifestations associated with A3243G mitochondrial DNA mutation.
The mitochondrial DNA A3243G transition is a fairly common mutation which often associates with a MELAS (mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes) phenotype, however, a broad variety in the associated clinical picture has also been described. The patient reported here developed a generalized seizure at age 12, which was followed by bilateral hearing loss and occasional fatigue. The maternal inheritance pattern of hearing loss pointed to a possible mitochondrial origin, which was confirmed by molecular analysis of the mitochondrial DNA, revealing a heteroplasmic A3243G transition. Interestingly, muscle biopsy showed ragged-red fibers in the proband, which is unusual in the deafness-associated forms of this mitochondrial disorder. In addition to hearing impairment in four generations of the family, fatal cerebral embolization in the mother and fatal heart attack in the maternal grandmother (both at age 33) also occurred. On the contrary, diabetes, which usually accompanies the hearing loss variant, was specifically absent in all generations. The unusual manifestations associated with this mutation somewhat differentiate this family from the already known variants.
Komlósi
Katalin
K
Department of Medical Genetics and Child Development, University of Pécs, Pécs, H-7624, Hungary.
Kellermayer
Richárd
R
Maász
Anita
A
Havasi
Viktória
V
Hollódy
Katalin
K
Vincze
Olga
O
Merkli
Hajnalka
H
Pál
Endre
E
Melegh
Béla
B
D002648:Child; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics*; D003638:Deafness / Q000235:genetics*; D004827:Epilepsy / Q000150:complications / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation; D006801:Humans; D010375:Pedigree; D010641:Phenotype; D017354:Point Mutation; D019851:Thrombophilia / Q000235:genetics
D004272:DNA, Mitochondrial