title: Molecular screening of intellectually disabled patients and those with premature ovarian failure for CGG repeat expansion at FMR1 locus: Implication of combined triplet repeat primed polymerase chain reaction and methylation-specific polymerase chain reaction analysis.
abstract: BACKGROUND
  Fragile X syndrome (FXS) is also a leading cause of intellectual disability along with Down's syndrome. It is caused by the expansion of CGG triplet repeat at 5' untranslated region of the fragile X mental retardation 1 (FMR1) gene. Since the prevalence rate is quite high in the general population, molecular diagnosis is important to establish the cause and the prenatal diagnosis. At present, there are a number of methods available with their own merits and demerits.
  
  
  OBJECTIVE
  Molecular screening of intellectually disabled patients and those with premature ovarian failure with combined triplet repeat primed polymerase chain reaction (TP-PCR) and methylation-specific polymerase chain reaction (MS-PCR) for establishing the diagnosis of FXS.
  
  
  RESULTS
  The specificity of the method has been validated with archived previously genotyped samples, facilitating the application of this method in the screening procedure. The combined TP-PCR and MS-PCR approach identified six (10%) of the intellectually disabled cases as full mutation positive, one (4%) of the premature ovarian failure cases as premutation positive, and one (out of two) of the prenatal samples as premutation positive.
  
  
  CONCLUSIONS
  The present study concludes that a combined usage of TP-PCR and MS-PCR will be a useful alternative approach to diagnose patients suffering from fragile X syndrome.
authors.affiliation: Department of Medical Genetics, Sanjay Gandhi Postgraduate Institute of Medical Genetics, Lucknow, Uttar Pradesh, India.
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Muthuswamy
authors.affiliation: Department of Medical Genetics, Sanjay Gandhi Postgraduate Institute of Medical Genetics, Lucknow, Uttar Pradesh, India.
authors.forename: Deepika Delsa
authors.initials: DD
authors.lastname: Dean
authors.affiliation: Department of Medical Genetics, Sanjay Gandhi Postgraduate Institute of Medical Genetics, Lucknow, Uttar Pradesh, India.
authors.forename: Sarita
authors.initials: S
authors.lastname: Agarwal
mesh_terms: D005260:Female; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics*; D005600:Fragile X Syndrome / Q000175:diagnosis* / Q000235:genetics; D005820:Genetic Testing / Q000379:methods; D006801:Humans; D008607:Intellectual Disability / Q000175:diagnosis*; D009154:Mutation; D016133:Polymerase Chain Reaction; D016649:Primary Ovarian Insufficiency / Q000175:diagnosis*; D018911:Trinucleotide Repeats
chemical_list: D051860:Fragile X Messenger Ribonucleoprotein 1; C497683:FMR1 protein, human