Hearing loss is one of the most common birth defects which can affect about 2 to 3 out of every 1,000 babies born. so far, more than 160 loci have been identified for non-syndromic hearing loss. pathogenic sequence variants in the tecta gene accounted for 1-10% of cases with the non-syndromic hereditary hearing loss.
given the importance of short tandem repeat (str) markers in prenatal diagnosis and preimplantation genetic diagnosis for deafness, a multiplex pcr for amplification of str markers linked to dfnb21 has been designed in this study.
Methods
Str markers were selected from mapviewer, or by using sequence-based estimation of repeat variability (serv) and tandem repeat finder (trf). primers for a multiplex pcr were designed using primer3, primer blast and gene runner. amplification of microsatellite
markers was performed using fluorescently labeled primers and fragment analysis was done on an abi 3130 genetic analyzer(lt). genotypes were determined using gene mapper id-x v.1
software (lt).
Results
Four tetranucleotide str markers were found for the tecta gene. two of the four selected strs were novel. str markers were amplified in a multiplex pcr. observed heterozygosity was more than 60 % for two of these markers. more than 10 different alleles were identified for one of the markers.
Conclusion
Designing a multiplex pcr for amplification of several markers can play a significant role in saving time and costs in prenatal diagnosis and preimplantation genetic diagnosis for deafness. more studies are needed to determine the exact characteristics of these markers.
