The protein tyrosine phosphatase non-receptor type I (PTPN1) 1484InsG polymorphism in the Maltese population

Abstract

The protein tyrosine phosphatase non-receptor type 1 gene (PTPNl) codes for the production of protein tyrosine phosphatase lB (PTPlB). This protein has been associated with the effective dephosphorylation of the insulin receptor resulting in the inhibition of insulin signaling. Its over expression has been associated with insulin resistance (Ahmad et al., 1997). The purpose of this study was to determine the allele frequency of the PTPNl 1484insG allele in the Maltese population and determine whether it is in Hardy-Weinberg equilibrium. A small study conducted by Zammit (2007) indicated the possibility that the PTPNl 1484insG polymorphism was not in Hardy Weinberg equilibrium in adult females subjects. For this reason newborns were used in the study. An allele frequency of 3.6% was observed in 196 Maltese newborns born in May/June 2011. This was considerably lower than that of the Italian population, which was 7.7% but it was similar to that observed in the Sicilian population which was 5.2% (Di Paola et al., 2002). There is an association between the PTPNl 1484insG polymorphism and high triglycerides, body mass index, total/HDL cholesterol and blood pressure (Di Paola et al., 2002). The involvement of the PTPNl 1484insG polymorphism in causing diabetes in the Maltese population still needs to be investigated.