The Arx Gene Mutation Qinba Mountain Children With Mental Retardation And Children's Intelligence

Qin-ba mountion area was the poor mountion area in the south of Shaanxi province, because of its badly, closed natural environment thus forming a relative separated population, after excluded environmental factors there still existed many mental retardation (MR) children, it shows gentice factors maybe involved.ARX is a newly found gene related with MR or NSMR, Molecular genetic studies showed there existed seven types of ARX gene mutation, two types of the aberrant expansion of polyA repeat tracts in exon 2 could lead to mutation mostly. To study this type of mutation, we seleted children age from 6~14 in An Kang and Zha Shui experimental centers in Qin-Ba mountain area through intelligence test and MR diagnosis. There were 500 children involved, in which 114 children were of MR, 103 children were of marginal intelligence, and the other 283 children were of normal intelligence. We use the experimental methods such as PCR, PAGE, T-cloning and DNA sequencing, after analyse the data, two males with the aberrant 24bp duplication in exon 2 was observed in An Kang experimental center. According to the intelligence test, their intelligence levels were low to normal range, differently, an effected individual's social adapt performance was normal, though his IQ was low to normal, it suggested that ARX gens mutation is not influence the behavior conducted by brain.In addition, through experiment, we find there wasn't exist many ARX gene mutations that led by aberrant expansion of polyA repeat tracts in exon 2, so, this kind of mutation may not the mainly genetic reasons that lead to mental retardation in our experimental centers in Qin-ba mountion area.