UNLABELLED: Only recently have mutations in MECP2 been found to be a cause of Rett Syndrome (RTT), a neuro-developmental disorder characterized by mental retardation, loss of expressive speech, deceleration of head growth and loss of acquired skills that almost exclusively affects females. We analysed the MECP2 gene in 31 patients diagnosed with RTT. Sequencing of the coding region and the splice sites revealed mutations in 24 females (77.40%). However, no abnormalities were detected in any of the parents that were available for investigation. Eleven mutations have not been described previously. Confirming two earlier studies, we found that most mutations are truncating and only a few of them are missense mutations. Several females carrying the same mutation display different phenotypes indicating that factors other than the type or position of mutations influence the severity of RTT. Four females with RTT variants were included in the study. Three of these presented with preserved speech while the fourth patient with congenital RTT lacked the initial period of normal development. Detection of mutations in these cases reveals that they are indeed variants of RTT. They represent the mild and the severe extremes of RTT. CONCLUSIONS: mutations in MECP2 seem to be the main cause for RTT and can be expected to be found in approximately 77% of patients that fulfil the criteria for RTT. Therefore analysis of MECP2 should be performed if RTT is suspected. Three mutation hotspots (T158M, R168X and R255X) were confirmed and a further one (R270X) newly identified. We recommend screening for these mutations before analysing the coding region.
UNLABELLED: Only recently have mutations in MECP2 been found to be a cause of Rett Syndrome (RTT), a neuro-developmental disorder characterized by mental retardation, loss of expressive speech, deceleration of head growth and loss of acquired skills that almost exclusively affects females. We analysed the MECP2 gene in 31 patients diagnosed with RTT. Sequencing of the coding region and the splice sites revealed mutations in 24 females (77.40%). However, no abnormalities were detected in any of the parents that were available for investigation. Eleven mutations have not been described previously. Confirming two earlier studies, we found that most mutations are truncating and only a few of them are missense mutations. Several females carrying the same mutation display different phenotypes indicating that factors other than the type or position of mutations influence the severity of RTT. Four females with RTT variants were included in the study. Three of these presented with preserved speech while the fourth patient with congenital RTT lacked the initial period of normal development. Detection of mutations in these cases reveals that they are indeed variants of RTT. They represent the mild and the severe extremes of RTT. CONCLUSIONS: mutations in MECP2 seem to be the main cause for RTT and can be expected to be found in approximately 77% of patients that fulfil the criteria for RTT. Therefore analysis of MECP2 should be performed if RTT is suspected. Three mutation hotspots (T158M, R168X and R255X) were confirmed and a further one (R270X) newly identified. We recommend screening for these mutations before analysing the coding region.
Authors: L Colvin; S Fyfe; S Leonard; T Schiavello; C Ellaway; N De Klerk; J Christodoulou; M Msall; H Leonard Journal: Arch Dis Child Date: 2003-01 Impact factor: 3.791
Authors: Malaika K Singleton; Michael L Gonzales; Karen N Leung; Dag H Yasui; Diane I Schroeder; Keith Dunaway; Janine M LaSalle Journal: Neurobiol Dis Date: 2011-03-21 Impact factor: 5.996
Authors: Hayley Archer; Julie Evans; Helen Leonard; Lyn Colvin; David Ravine; John Christodoulou; Sarah Williamson; Tony Charman; Mark E S Bailey; Julian Sampson; Nicholas de Klerk; Angus Clarke Journal: J Med Genet Date: 2006-08-11 Impact factor: 6.318