Evaluation of a Genetic Test for Diagnose of Primary Hypolactasia in Northeast of Iran (Khorasan)

Objective(s) Primary or adult type hypolactasia, the most common enzyme deficiency in the world, is due to reduced lactase activity in the intestinal cell after weaning. Lactase non-persistence is inherited as an autosomal recessive trait. A DNA variant, single nucleotide polymorphism C/T−۱۳۹۱۰ which is located on ۱۳۹۱۰ base pairs (bp) upstream of the lactase gene (LCT) at chromosome ۲ has been show to associate with the lactase persistence/non-persistence. The prevalence of the C/T-۱۳۹۱۰ variant is different for hypolactasia in European, Asian, African-American and Northern African populations. In this study, we investigated, for the first time the allele frequent of the single nucleotide polymorphism C/T−۱۳۹۱۰ in the Iranian population in khorasan province with hypolactasia. Materials and Methods Peripheral blood was collected from ۱۰۰ subjecs with primary hypolactasia and ۱۰۰ healthy individuals as a control group. Genomic DNA was extracted. The genotype was analyzed with the PCR-RFLP method. A statistical analysis was performed by chi-square test using SPSS software. A P-value of <۰.۰۵ was considered statistically significant.ResultsIn case group allelic frequency for SNP T-۱۳۹۱۰C (C, T) was respectively ۹۵%, ۵% vs. control group ۸۶% and ۱۴%. Genotype frequency (CC, CT, TT) in patient group was ۹۰%, ۱۰%, ۰% vs. control group ۷۴%, ۲۴% and ۲%. So according to our findings, there were significant differences between allelic frequencies (P=۰.۰۳), and in genotype frequency between case and control groups (P=۰.۰۰۶).ConclusionBased on our results, analysis of C\T-۱۳۹۱۰ polymorphism can be used as a simple genetic test for diagnosis of primary type hypolactasia in the Iranian population.