The +1858 C/T Polymorphism in the PTPN22 Gene Is Associated with Cystic Fibrosis Patients in Northeast Mexico.

Cystic fibrosis (CF) is the most common autosomal recessive disease in the Caucasian population, but it has also been widely diagnosed in the Mexican population. Production of viscous secretions affects the secretory epithelia and the respiratory condition usually leads to death. The relationship between the CFTR genotype and the disease phenotype is not well understood. Other risk factors such as genetic and autoimmune influence the development of this disease. We analyzed the PTPN22 R620W polymorphism (+1858 C/T, rs2476601) in 78 DNA samples from CF patients and 232 healthy controls from northeast Mexico using the polymerase chain reaction-restriction fragment length (PCR-RFLP) method. The C allele and the CC genotype were the most frequently detected in controls (CC genotype 96.12%; C allele 98.06%) compared with CF patients (CC genotype 88.46%, C allele 93.59%). A statistically significant association for the CT + TT genotypes (p = 0.012, OR = 3.232) as well as for the mutant T allele (p = 0.005, OR = 3.463) was found when comparing CF patients with controls. A significant association was found between the rs2476601 polymorphism of the PTPN22 gene and CF in Mexican patients. Further studies are necessary to understand the influence of this variant on lung neutrophil function and disease development.