First study of the polymorphic marker MP6D9 in a population of children with cystic fibrosis

Abstract

Since the identification of the CFTR gene (Cystic Fibrosis Transmembrane Regulator) responsible for cystic fibrosis (CF), over 1900 mutations are described. This large molecular heterogeneity can explain in part the significant clinical variability of the disease which may be due to environmental or genetic factors. With the development of molecular biology techniques, more and more genetic markers can be tested to study the clinical variability of cystic fibrosis. In this work, we are interested for the first time to study the extragenic polymorphic marker MP6D9 in a CF Tunisian population. Our study involved 60 CF Tunisian patients with a positive sweat test ([Cl-]>60mmol/L). A cohort of 45 healthy controls was also enrolled. The analysis of the polymorphic marker MP6D9 was performed by PCR-RFLP. The distribution of MP6D-9 genotypes and alleles was significantly different between CF and healthy subjects. We noted that the 2/2 genotype was higher in CF patients than in controls (73.33% vs 15.55%), whereas the frequency of the 1/2 genotype was lower in our patients (53.33% vs 18.33%). Our results are consistent with those found in the literature which confirms the involvement of this marker in the clinical presentation and evolution of cystic fibrosis. The study of polymorphism MP6D9 is one of the first research in the CF Tunisian population which allowed us to show the involvement of this marker in the expression of cystic fibrosis in our population.