Only male matrilineal relatives with Leber's hereditary optic neuropathy in a large Chinese family carrying the mitochondrial DNA G11778A mutation.
We report here the characterization of a five-generation large Chinese family with Leber's hereditary optic neuropathy (LHON). Very strikingly, six affected individuals of 38 matrilineal relatives (17 females/21 males) are exclusively males in this Chinese family. These matrilineal relatives in this family exhibited late-onset/progressive visual impairment with a wide range of severity, ranging from blindness to normal vision. The age of onset in visual impairment varies from 17 to 30 years. Sequence analysis of the complete mitochondrial genome in this pedigree revealed the presence of the G11778A mutation in ND4 gene and 29 other variants. This mitochondrial genome belongs to the Southern Chinese haplogroup B5b. We showed that the G11778A mutation is present at near homoplasmy in matrilineal relatives of this Chinese family but not in 164 Chinese controls. Incomplete penetrance of LHON in this family indicates the involvement of modulatory factors in the phenotypic expression of visual dysfunction associated with the G11778A mutation. However, none of other mtDNA variants are evolutionarily conserved and implicated to have significantly functional consequence. Thus, nuclear modifier gene(s) or environmental factor(s) seem to account for the penetrance and phenotypic variability of LHON in this Chinese family carrying the G11778A mutation.
Qu
Jia
J
School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, Zhejiang 325003, China.
Li
Ronghua
R
Tong
Yi
Y
Hu
Yongwu
Y
Zhou
Xiangtian
X
Qian
Yaping
Y
Lu
Fan
F
Guan
Min-Xin
MX
D044466:Asian People / Q000706:statistics & numerical data; D002681:China / Q000453:epidemiology; D004252:DNA Mutational Analysis; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D008297:Male; D029242:Optic Atrophy, Hereditary, Leber / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics*; D010375:Pedigree; D010802:Phylogeny; D011237:Predictive Value of Tests; D015995:Prevalence; D012016:Reference Values; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012737:Sex Factors
D004272:DNA, Mitochondrial