[Correlation between degree of mitochondrial DNA 1555 mutation and clinical phenotype of nonsyndromic hearing loss].
OBJECTIVE
To study the correlation between the number of mtDNA (mitochondrial DNA) copies containing mtDNA A1555G mutation site and phenotype and further elucidate the molecular genetic basis of phenotype diversity of nonsyndromic hearing loss.


METHODS
Real time-amplification refractory mutation system-quantitative PCR was employed to detect the number of mtDNA copies in mild type and mutant type of mtDNA 1555.


RESULTS
In the sporadic group, there was no significant correlation between mtDNA A1555G homogeneity mutation copies and phenotype (R = 0.001, P = 0.997) while significant correlation existed between mtDNA A1555G heteroplasmic mutations and phenotype (R = 0.771, P = 0.003). In the familial group there was significant correlation mtDNA 1555 homogeneity mutation copies and phenotype (R = 0.341, P = 0.022) and significant correlation existed between mtDNA 1555 heterogenicity mutation copies and phenotype (R = 0.85, P = 0.015).


CONCLUSIONS
There is significant correlation between the mtDNA A1555G mutation copies and the severity of hearing loss.
Department of Laboratory Medicine, Department of Otolaryngology, First Affiliated Hospital, Department of Gene Diagnosis, Fujian Medical University, Fuzhou, China.
Zu-jian
ZJ
Cheng
Rong
R
Zhang
Bin
B
Yang
Qi-cai
QC
Liu
Ling
L
Jiang
Jing
J
Chen
Yong
Y
Chen
Qi-shui
QS
Ou
D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D034381:Hearing Loss / Q000235:genetics*; D006801:Humans; D008297:Male; D009154:Mutation; D010641:Phenotype
D004272:DNA, Mitochondrial