Genotype and Allele Frequencies of Calcium-Sensing Receptor Gene a986s (rs1801725) Polymorphism in Saudi Adults

Objectives

To determine the genotype and allele frequencies of the calcium sensing receptor (CaSR) gene A986S (rs1801725) polymorphism in healthy Saudi adults of both sexes and compare these frequencies with those in various ethnic groups.

Methods

The study included 113 subjects, including 50 males and 63 females. The genotypes of polymorphic position A986S were determined by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay.

Results

The genotype frequency in males was 26% (n=13) normal (AA), 56% (n=28) heterozygous (AS) and 18% (n=9) homozygous (SS), and the allele frequencies for the A and S alleles were 54% and 46%, respectively. The genotype distribution was out of Hardy- Weinberg equilibrium (goodness of fit X2=0.80, df=1, P=0.00001). The genotype frequency in females was 49.21% (n=31) normal (AA), 36.51% (n=23) heterozygous (AS), and 14.29% (n=9) homozygous (SS), and the allele frequencies were 67% and 32.54% for the A and S alleles, respectively. The genotype distribution was out of Hardy- Weinberg equilibrium (goodness of fit X2=1.78, df=1, P=0.07).

Conclusions

The genotype frequencies of the CaSR polymorphism rs1801725 for the normal genotype AA were 75.21%, for the heterozygous genotype AS were 92.51% and for the homozygous genotype SS were 32.29%. The frequencies of the A and S alleles were 121.46 and 78.54%, respectively. The heterozygous genotype was higher in males, whereas the normal genotype was higher in females.