Neurofibromatosis Type 1 (NF1) is a common autosomal dominant single-gene disorder, in which the co-occurrence of autism spectrum disorder (ASD) has attracted considerable research interest recently with prevalence estimates of 21-40%. However, detailed characterization of the ASD behavioral phenotype in NF1 is still lacking. This study characterized the phenotypic profile of ASD symptomatology presenting in 4-16 year old children with NF1 (n = 36) using evidence from parent-rated Social Responsiveness Scale and researcher autism diagnostic observation Scale-2. Compared to IQ-matched reference groups of children with autism and ASD, the NF1 profile shows overall similarity but improved eye contact, less repetitive behaviors and better language skills.

The present study aimed to gain more insight in the social behavioral phenotype, and related autistic symptomatology, of children with an extra X chromosome in comparison to children with ASD. Participants included 60 children with an extra X chromosome (34 boys with Klinefelter syndrome and 26 girls with Trisomy X), 58 children with ASD and 106 controls, aged 9 to 18 years. We used the Autism Diagnostic Interview, Social Responsiveness Scale, Social Anxiety Scale and Social Skills Rating System. In the extra X group, levels of social dysfunction and autism symptoms were increased, being in between controls and ASD. In contrast to the ASD group, the extra X group showed increased social anxiety. The effects were similar for boys and girls with an extra X chromosome.

No abstract

Recently, Hagerman et al described the occurrence of a late-onset neurological disorder in five male carriers of the fragile-X (FMR-1) premutation. The major characteristics of this disorder, designated the Fragile-X Tremor Ataxia Syndrome (FXTAS), are progressive intention tremor, cerebellar ataxia and cognitive decline. Most cases of FXTAS published thus far were ascertained through families with a known fragile-X proband. Since cerebellar ataxia is one of the main cardinal features, we performed FMR-1 premutation screening in 122 male patients, older than 50 years, who were referred to us for testing of the spinocerebellar ataxia (SCA 1, 2, 3, 6, 7) genes and who were found to be negative. In this group of patients, we found five patients with an FMR-1 premutation. In four of them, a definite diagnosis of FXTAS could be made, based on the proposed diagnostic clinical and radiological criteria for FXTAS. In light of these figures, we recommend that FMR-1 analysis should be included in the molecular diagnostic work-up in the group of male ataxia patients older than 50 years. The presence of symmetrical regions of increased T2 signal intensity in the middle cerebellar peduncles (MCP) and adjacent white matter is thought to be a specific sign and included as radiological inclusion criterion for this syndrome. Data of a large survey have demonstrated an agerelated penetrance of the combination of reported tremor and ataxia in male premutation carriers, going up to 47% in the group of 70 -79 years. 3Most cases of FXTAS published thus far were ascertained through families with a known fragile-X proband. Since cerebellar ataxia is one of the main cardinal features, we decided to perform fragile X premutation screening in male patients, who were referred to our laboratory for testing of the spinocerebellar ataxia (SCA) genes and who were found to be negative for the expansion. We retrospectively selected all male probands with ataxia, who were 50 years or older at the time of referral. Of 137 patients, 15 (10.9%) were found positive for an (CAG)n expansion in one of the SCA genes. Of the remaining 122 men, all were

In this report we present the results of a study of the intellectual functioning and cognitive profile of 26 Prader‐Willi syndrome (PWS) patients. The mean IQ score was 62.3 (range 39–96). In 13 patients a significant difference between verbal and performance IQ was found. In 10 of them the performance IQ was higher than the verbal. The results of subtest analysis indicate that cognitive strengths are more visible than cognitive weaknesses. Highest scores were noted especially in the performance scale, i.e. Block Design (9 children) and Coding or Mazes (5 children). Analysis of all available data indicates that PWS patients score better on visual motor discrimination skills than on auditory verbal processing skills. These results are promising for intervention programs and education stiategies.