PURPOSE: To investigate the incidence and clinical significance of primary or proposed secondary mitochondrial DNA (mtDNA) mutations in Japanese @entity1 with @entity3054 ( @entity3054 ). METHODS: Blood samples from the 80 unrelated Japanese @entity1 with bilateral @entity1952 were screened for primary @entity3054 mutations. @entity1 found to have a primary @entity3054 mutation were then tested for 9 proposed secondary @entity3054 mutations. We investigated the association between these mutations and clinical characteristics. RESULTS: Primary mtDNA mutations were identified in 68 @entity1 : at np 3460 in 3 (4%) of 68 @entity1 , at np 11,778 in 59 @entity1 (87%), and at np 14,484 in 6 @entity1 (9%). We identified 5 secondary mtDNA mutations (at np 3394, 4216, 7444, 9438 or 13,708) in 10 (15%) of 68 @entity3054 @entity1 and 3 mutations (at np 3394, 4216 or 3708) in 6 (7%) of 90 healthy Japanese individuals. No @entity1 was positive for more than one secondary mutation. The frequency of secondary mutations was similar in the 68 @entity3054 @entity1 and 90 controls. The clinical features of the Japanese @entity1 with any of the 3 primary @entity3054 mutations were similar to those of Caucasian @entity1 , despite different mtDNA backgrounds in these populations. The percentage of @entity1 with familial @entity3054 harboring the 3460 or 14,484 mutations was lower in the Japanese population. CONCLUSIONS: Japanese @entity1 with @entity3054 exhibited a very high incidence (87%) of the 11,778 primary mutation. Most of the proposed secondary @entity3054 mutations were rare in the Japanese population and they, except the 7444 mutation, may not influence the clinical features of @entity3054 .

Spectrum of pathogenic mitochondrial DNA mutations and clinical features in Japanese families with XXXX .

@entity1 :: ('9606', 'Species') :: ['Patients', 'patients', 'patient'] @entity3054 :: ('MESH:D029242', 'Disease') :: ["Leber's hereditary optic neuropathy", 'LHON'] @entity1952 :: ('MESH:D009896', 'Disease') :: ['optic atrophy']
@entity3054 :: (MESH:D029242,Disease) :: ['Leber's hereditary optic neuropathy']
