[Mitochondrial DNA A1555G mutation of seven families with nonsyndromic hearing loss].
OBJECTIVE
To study mitochondrial DNA (mtDNA) A1555G mutation in seven families with nonsyndromic hearing loss (NSHL).


METHODS
Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and real time-amplification refractory mutation system-quantitative PCR (ARMS-qPCR) were applied to detect mtDNA A1555G mutation in seven NSHL families. Related clinical data were also collected and analyzed.


RESULTS
The mtDNA A1555G mutation was detected in members from the maternal side, including heteroplasmy and homozygosis, others were negative for this mutation. The copy number of homoplasmic or heteroplasmic mutations of mtDNA A1555G correlated well with the degree of deafness (R = 0.341, P = 0.022 and R = 0.85, P = 0.015, respectively).


CONCLUSIONS
The mutation rate of the mtDNA A1555G is high in the NSHL patients, the mutation type include heteroplasmy and homozygosis. There is significant correlation between the mtDNA A1555G copy number and the severity of hearing loss.
Ou
Qi-shui
QS
Department of Laboratory Medicine, First Affiliated Hospital, PR China. ouqishui@163.com
Cheng
Zu-jian
ZJ
Yang
Bin
B
Jiang
Lin
L
Chen
Jing
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002675:Child, Preschool; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D018628:Gene Dosage; D034381:Hearing Loss / Q000235:genetics* / Q000473:pathology; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D017354:Point Mutation; D055815:Young Adult
D004272:DNA, Mitochondrial