Screening of ARX gene mutations in mentally retarded people

Mental retardation (MR) is a failure to develop cognitive abilities and achieve a level of intelligence as well as ?adaptive behaviors? when compared the same age group. The ARX gene is responsible for MR after FMR1 gene. Both syndromic and nonsyndromic conditions of MR are involved in the ARX gene mutations. The most common mutations in the ARX gene are c.334ins(GCG)7 and c.428_451dup which cause the increasing number of alanine amino acid. Mental retardation as well as some central nervous system and urogenital system diseases have been associated with the ARX gene mutations.In this study, we tested the ARX gene?s the most common mutations, c.334ins(GCG)7 and c.428_451dup, with Polymerase Chain Reaction (PCR) fallowing the DNA isolation from peripheral blood samples of 125 pediatric mental retarded males referred as FXS/MR consultated to Department of Medical Biology and Genetics, Medical Faculty, Akdeniz University, and diagnosed as the number of CGG repeats of FMR1 gene are normal. PCR products were run on high resolution agarose gel electrophoresis with marker. Possible genomic alterations were analyzed with DNA sequencing.As a result any genomic alterations were not detected. In conclusion, it can be suggested that the c.334ins(GCG)7 and c.428_451dup mutations of the ARX gene are not responsible for etiopathogenesis of mentally retarded males in Antalya. However, we think that whole ARX gene should be screened to detect the other mutations responsible for mental retardation after exclusion of the hot spot mutations of ARX gene to give a realistic genetic counseling for more healthy population.