A Pilot Study on Assessment of Triplet Repeat Primed PCR for Fragile X Syndrome Diagnosis

Abstract

FMR1 gene contains a stretch of CGG repeat that usually remains less than 45 in healthy subjects. However when goes beyond 200, it results in developmental delay or mental retardation called fragile X syndrome (FXS). The repeat number between 56 and 200 are reported to be associated with fragile X associated tremor/ataxia syndrome and primary ovarian failure. Therefore the number of CGG repeat at FMR1 gene (5’UTR) determines the nature of disease. Though, there are multiple molecular methods are available for FXS diagnosis, TP-PCR is more rapid and straightforward in providing diagnosis. Thus, present study was aimed to assess the diagnostic applicability of TP-PCR optimized in our lab. The diagnosis was made on 20 samples and results of the present study were found to be concordant with diagnosis made from other lab. Our method can differentiate normal, premutation and full mutation alleles. Accurate sizing is possible for normal and premutation range. We conclude that our method is cost effective, rapid and accurate in diagnosis of FXS cases as well as premutation carriers.