@entity3055 and XXXX .

@entity1 @entity3055 @entity2045 @entity303 @entity2055 @entity508 @entity75 @entity880 @entity3316 @entity3148 @entity393 @entity2388
A family is described with familial @entity3148 associated with @entity3055 . The disorder follows a maternal inheritance pattern consistent with a mitochondrial DNA (mtDNA) mutation. The large kindred permitted exclusion of autosomal dominant, recessive, and X-linked patterns of transmission. Several characteristics of the inheritance and variability of expression within the pedigree are consistent with recently acquired knowledge about the genetics of @entity1 mtDNA. The clinical spectrum of disease is compatible with a proportionality model of mutant and wild-type mtDNAs. Muscle biopsies of affected @entity1 showed an increased number of abnormal muscle mitochondria. Serum levels of @entity2388 or @entity2388 and @entity880 were elevated. The most severely affected @entity1 had constant @entity2045 , @entity303 , @entity2055 , @entity508 , @entity393 , and @entity3316 . @entity75 in @entity1 with mild involvement was marked by prominent photic driving seen on electroencephalograms and high-amplitude visual and somatosensory evoked responses but no @entity2045 , @entity2055 , or @entity303 . The individual clinical features of the disease worsen over time for all @entity1 ; however, mildly affected @entity1 have not become moderately affected and moderately affected @entity1 have not become severely affected.
