Mentally retarded patients without 15q11-q13 defects should have MECP2 analysis.

2004 MAR 4 - (NewsRx.com & NewsRx.net) -- Mentally retarded patients without 15q11-q13 defects should have MECP2 analysis.

"Rett syndrome (RTT) is one of the most common neurodevelopmental disorders in females. The disease is caused by mutations in the methyl-CpG-binding protein 2 gene (MECP2), and various mutations have been reported. The phenotypic spectrum in both female and male patients is diverse, ranging from very mild to congenital encephalopathy and prenatal lethality," investigators in the Netherlands report.

"In this study, the question was addressed as to whether implementation of systematic screening of MECP2 in patients with an unexplained mental retardation in DNA diagnostics would be reasonable, and the spectrum of phenotypes resulting from mutations in this gene was further explored. Mutational analysis of MECP2 was performed in mentally retarded female patients who were negative for FMR1 CGG repeat expansion, and in male and female patients with clinical features suggestive of either Angelman or Prader-Willi syndrome without methylation defects on chromosome 15q11-q13," wrote T. Kleefstra and colleagues, University Medical Center St. Radboud, Department of Human Genetics.

"In the cohort of females negative for the molecular Fragile-X studies (n=92), one nonsense mutation (p.Q406X) was found. In the cohort of Angelman-negative patients (n=63), two missense mutations (p.R133C in ...