1. Bishop DV, Jacobs PA, Lachlan K, Wellesley D, Barnicoat A, Boyd PA, Fryer A, Middlemiss P, Smithson S, Metcalfe K, Shears D, Leggett V, Nation K, Scerif G. {{Autism, language and communication in children with sex chromosome trisomies}}. {Arch Dis Child} (Jul 23)
Purpose Sex chromosome trisomies (SCTs) are found on amniocentesis in 2.3-3.7 per 1000 same-sex births, yet there is a limited database on which to base a prognosis. Autism has been described in postnatally diagnosed cases of Klinefelter syndrome (XXY karyotype), but the prevalence in non-referred samples, and in other trisomies, is unclear. The authors recruited the largest sample including all three SCTs to be reported to date, including children identified on prenatal screening, to clarify this issue. Design Parents of children with a SCT were recruited either via prenatal screening or via a parental support group, to give a sample of 58 XXX, 19 XXY and 58 XYY cases. Parents were interviewed using the Vineland Adaptive Behavior Scales and completed questionnaires about the communicative development of children with SCTs and their siblings (42 brothers and 26 sisters). Results Rates of language and communication problems were high in all three trisomies. Diagnoses of autism spectrum disorder (ASD) were found in 2/19 cases of XXY (11%) and 11/58 XYY (19%). After excluding those with an ASD diagnosis, communicative profiles indicative of mild autistic features were common, although there was wide individual variation. Conclusions Autistic features have not previously been remarked upon in studies of non-referred samples with SCTs, yet the rate is substantially above population levels in this sample, even when attention is restricted to early-identified cases. The authors hypothesise that X-linked and Y-linked neuroligins may play a significant role in the aetiology of communication impairments and ASD.
2. Shapiro JR, Bibat G, Hiremath G, Blue ME, Hundalini S, Yablonski T, Kantipuly A, Rohde C, Johnston M, Naidu S. {{Bone Mass in Rett Syndrome: Association with Clinical Parameters and MECP2 Mutations}}. {Pediatr Res} (Jul 23)
Rett Syndrome (RTT) is an X-linked neurodevelopmental disorder caused by mutations in the MECP2 gene. In 49 female RTT children, ages 1.9-17 years, bone mass was assessed and correlated with clinical parameters and mutations involving the MECP2 gene. We also studied 5 adult females, ages 20-33 years, and one male, age 6 years. Lumbar spine bone mineral content (BMC) and bone mineral density (BMD) were correlated with weight, height, body mass index, clinical severity, degree of scoliosis, use of anticonvulsants and ambulatory status. L1-L4 BMD and BMC showed that 48.9% of them had BMD values greater than 2 SD below age-related norms. BMD values were in the osteoporotic range in the 5 adult females with RTT. Eleven percent of the children and adults with RTT experienced fractures. Low bone mass was correlated with marginal significance to clinical severity and ambulation, but not to scoliosis or anticonvusant use. Lowest bone mass occurred in patients with T158M or R270X mutations but without statistical significance. Studies in a murine model of RTT confirmed low bone mass as an inherent component of this syndrome. MECP2 mutations and clinical parameters impact bone mass in RTT but an association with a specific mutation was not demonstrable. ABBREVIATION LIST::
