IVS8 polyT and M470V polymorphisms in healthy individuals and cystic fibrosis patients in Mazandaran province, Iran

Cystic fibrosis (CF) is a multiorgan autosomal recessive disorder. As CF is highly heterogeneous in Iran and many mutations have a low frequency, routine molecular diagnostic methods are not very efficient. The use of highly polymorphic intragenic markers not only can facilitate phenotype prediction in prenatal diagnosis by gene tracking, but also can lead to the demonstration of possible associations between haplotypes and specific mutations. We determined IVS8 polyT and M470V polymorphisms in exon 10 of CFTR gene in this case-control study.

Polymorphisms of IVS8 polyT in 53 patients with CF were referred to Amirkola children's Hospital of Babol University of Medical Sciences, 2007 to 2011 and 49 fertile healthy individuals were determined by reverse dot blot method. M470V polymorphism was analyzed by PCR-RFLP.

In IVS8 polyT study, T7 was the most frequent allele in healthy individuals than patients with CF (respectively, 82.8% Vs. 77.2%). T9 was more abundant in patients with CF than normal individuals (respectively, 21.7% Vs. 7.4%, P=0.005). T9/T9 genotype was more frequent in patients than healthy individuals (respectively, 15.1% and 2%, P=0.032). Study for M470V polymorphism showed that M/V was the most common genotype in normal individuals and patients with CF (respectively, 49% and 40.4%). M-T9 haplotype was highly associated with the disease in both patients with CF and normal individuals (respectively, 19.1% and 2.4%, (P<0.001)

The allelic distribution and heterozygosity results suggest that both M470V and IVS8 polyT can be helpful in the prenatal diagnosis of CF in Northern Iranians with a positive family history of the disease.