[Studying VSX1 gene mutations in patients with keratoconus of chaharmahal and Bakhtiari Province, Iran]

Background and Aims: Keratoconus [KC] is an eye disorder in which the cornea is swollen, thinned and deformed. Despite extensive studies, the pathophysiological processes and genetic etiology of KC is unknown. The disease incidence is approximately 1 in 2000 and is the most common cause of corneal transplantation in the US. Many genes are involved in the disease, but evidence suggests a major role for VSX1 in the etiology of KC. This study aimed to determine the frequency of mutations in exons 2, 4 of the VSX1 gene in Chaharmahal and Bakhtiari province, Iran

Methods: In this experimental study, mutations in two exons including exons 2 and 4 of VSX1 were investigated in 50 patients with KC. DNA was extracted using a standard phenol-chloroform method. PCRSSCP/HA was performed, followed by DNA sequencing to confirm the identified motility shift

Results: H244R mutation was identified in exon 4 of only one patient

Conclusion: Our investigation showed that the KC-related VSX1 mutations are found in very small samples in the study subjects from Iran. Further investigations on other genes are needed to clarify their roles in KC pathogenesis

Two novel mutations and predominant 35delG mutation in the connexin 26 gene [GJB2] in Iranian populations

Mutations in the GJB2 gene encoding Connexin 26 [Cx26] protein are a major cause for autosomal recessive non syndromic and sporadic deafness in many populations. In this study we have investigated the prevalence of the GJB2 gene mutations using nested PCR pre screening strategy and direct sequencing method. Two hundred and sixty autosomal recessive non syndromic and sporadic deaf subjects from 199 families in two provinces of Iran [Gilan and Khorasan] were studied. Altogether 14 different genetic variants were identified from which 2 were novel variant [327delG+G109G and 431insC]. Eight GJB2 mutations including 35delG, 235delC, W77X, R127H, M34T, V27I+E114G, L90P and delE120 were also found in 54 of 199 families [27%]. Four polymorphysms V27I, S86T, V153I and G160S also were detected. Thirty two of 199 families were observed to have GJB2 mutations in both alleles [16%]. The most common mutation was 35delG so that 43 out of 55 GJB2 mutations [78.2%] contained 35delG mutation