Background: Hearing loss is a sensorineural disorder occuring in 1 out of 500 births. It happens due to some genetic/environmental causes or both. More than 60% of cases are noninherited and 80% non syndromic with autosomal recessive inheritance. In the present study we investigated the frequency of mtDNA A1555G, A3243 and A7445G mutations among the patients in Fars province.

Materials and Methods: Seventy two non syndromic hearing loss subjects were studied. DNA was extracted using standard phenol-chloroform method. The screening of the mitochondrial gene mutations were performed using PCR-RFLP procedure. Finally, the possible mutations were confirmed by direct sequencing.

Results: None of the A1555G, A3243G and A7445G mutations was detected in this study. However, destroying a MTTL1 restriction site for the investigation of A3243G mutation, revealed a G3316A with allelic variant of 1.4% in the deaf subjects.

Conclusion: Our data indicated that the mitochondrial A1555G, A3243 and A7445G mutations have no role in auditory deficits in patients studied.