Background: SLC26A4 gene mutations are the second currently identifiable genetic cause of autosomal recessive non syndromic hearing loss (ARNSHL) after GJB2 mutations. In databases, several potential STR markers related to this region have been introduced. In this investigation, the identity and informativeness of D7S2459 CA repeat STR marker in SLC26A4 gene region was examined in five ethnic groups of the Iranian population.

Materials and Methods: The research study was accomplished by genotyping the locus in 165 individuals of five different ethnic groups including Fars, Azari, Torkaman, Gilak and Arab using polymerase chain reaction (PCR) followed by polyacrylamide gel electrophoresis (PAGE) and fluorescent capillary electrophoresis. In this study, results were analyzed by GeneMarker HID Human STR Identity software, GenePop program and Microsatellite Tools software.

Results: Analysis of the allelic frequency revealed the presence of 8 alleles for D7S2459 marker in the Iranian population. Among all, allele 148bp at the D7S2459 locus with 31% frequency was the most frequent. The Azari ethnic with 84.8% observed heterozygosity was the highest among all ethnic groups. Finally, analysis of PIC value revealed that D7S2459 marker could be considered as a highly informative marker in each ethnic of the Iranian population (PIC value above 0.7).

Conclusion: Our data suggested that D7S2459 could be introduced as a highly informative marker in molecular diagnosis of SLC26A4 based ARNSHL by Linkage analysis.

Background: Preeclampsia (PE) is a serious problem of pregnancy and its etiology is still unknown. The inheritance of preeclampsia is one of the theories regarding to the etiology of preeclampsia. Methylenetetrahydrofolatereductase (MTHFR) is a key enzyme in folate metabolism and the C677T polymorphism of the MTHFR gene is associated with decrease MTHFR activity, and therefore cause higher blood levels of homocysteine and leads to vascular disease that can be the reason of preeclampsia. The aim of this study was to evaluate the relationship between MTHFR gene C677T polymorphism with PE development in south-west of Iran.

Materials and Methods: This case-control study was performed in 129 preeclamptic pregnant women and 125 control individuals.The C677T polymorphism of the MTHFR gene was determined by PCR-RFLP method.

Results: The CC, CT and TT genotypes frequency of C677T polymorphism of MTHFR gene were 57.4, 38.8 and 3.9 percent in preeclamptic women and 53.6, 40 and 6.4 percent in control group. They were not significantly different (p=0.614). However, the frequency of TT genotype was higher in control group (p=0.36). There was not any significant difference in T allele distribution between preeclamptic women (23.3%) and control group (26.4%).

Conclusion: Our results showed that there was not any correlation between the C677T polymorphism and PE but the TT genotype of C677T polymorphism seems to be a protective factor for preeclampsia.

Abstract

Background: Hearing loss (HL) is the most common congenital defect in humans. One or two in thousand newborn babies have prelingual hearing loss. Autosomal recessive non-syndromic hearing loss (ARNSHL) is the most common form of hereditary deafness. Hearing loss is more common in the developing countries which is due to genetic and environmental (cultural -health factors) reasons. HL has a wide range of clinical demonstrations including: congenital or late onset, conductive or sensory-neural, syndromic or non-syndromic hearing loss. The goal of this project is to determine the portion of the DFNB21 (TECTA) in ARNSHL in families with negative GJB2 gene in Khuzestan province.

Materials and Methods: We studied 21 families with ARNSHL with at least 4 patients and negative for GJB2 mutations from Khuzestan province. Genetic linkage analysis was performed using STR markers linked to DFNB21 locus.

Results: Following genetic linkage analysis and haplotyping, out of 21 families with ARNSHL, one family showed linkage to the DFNB21 (TECTA) locus.

Conclusion: The results of this project confirm other studies in Iran and give insight into the most common loci causing ARNSHL in Iran which could be helpful in research and clinic.