Genetic disorders and spermatogenesis.

Male infertility affects one man in twenty and a genetic basis seems likely in at least 30% of those men. Genetic regulation of fertility involves the inter-related processes of testicular development, spermatogenesis (involving germ cell mitosis, meiosis and spermatid maturation), and their endocrine and paracrine regulation. In regard to spermatogenesis, particular attention has been given to the Yq11 region, where some spermatogenesis genes ('azoospermia factors') appear to be located. Several candidate genes have been identified but have not been shown to have a defined or essential role in spermatogenesis. Microdeletions of Yq11 are found in approximately 15% of azoospermic or severely oligospermic men. The complexity of the genetic control of male fertility is demonstrated by the evidence for genes involved in spermatogenesis and sexual differentiation on the X chromosome and autosomes. Better understanding of the genetic regulation of normal spermatogenesis will provide new probes for clinical studies; however, at present the majority of spermatogenic failure remains without an identified genetic linkage. The advent of intracytoplasmic sperm injection permits fertility in many previously sterile men and presents the possibility of their transmission of infertility; appropriate counselling is required.

Imitation and 'theory of mind' competencies in discrimination of autism from other neurodevelopmental disorders

Several studies have reported imitative deficits in autism spectrum disorder (ASD). However, it is still debated if imitative deficits are specific to ASD or shared with clinical groups with similar mental impairment and motor difficulties. We investigated whether imitative tasks can be used to discriminate ASD children from typically developing children (TD) and children with general developmental delay (GDD). We applied discriminant function analyses to the performance of these groups on three imitation tasks and tests of dexterity, motor planning, verbal skills, theory of mind (ToM). Analyses revealed two significant dimensions. The first represented impairment of dexterity and verbal ability, and discriminated TD from GDD children. Once these differences were accounted for, differences in ToM and the three imitation tasks accounted for a significant proportion of the remaining intergroup variance and discriminated the ASD group from other groups. Further analyses revealed that inclusion of imitative tasks increased the specificity and sensitivity of ASD classification and that imitative tasks considered alone were able to reliably discriminate ASD, TD and GDD. The results suggest that imitation and theory of mind impairment in autism may stem from a common domain of origin separate from general cognitive and motor skill.

Upon Sleep

Poem

Sleep complaints and risk factors for excessive daytime sleepiness in adult males in Northern Ireland

The prevalence of sleep complaints in Northern Ireland is unknown. Sleep disruption can result in excessive daytime sleepiness (EDS), with significant socioeconomic consequences. The aim of this study was to assess the prevalence of sleep complaints and to determine risk factors for EDS in a Northern Irish community. From an urban and rural community of 499 111 people, a random sample of 3391 adult men were sent a questionnaire by mail. Questions were asked regarding sleep, EDS and medical history. There were 2364 completed questionnaires returned (response rate 70%). The mean age of respondents was 46.0 years (range 18-91 years). 26.7% of men were not satisfied with their usual night's sleep and 68% of men woke up at least once during the night. Based on pre-defined criteria, 24.6% of the population had insomnia and 19.8% had EDS. The strongest risk factor identified for EDS was a history of snoring loudly (odds ratio 2.62; 95% CI 1.82-3.77). Other risk factors included ankle swelling, feeling sad or depressed stopping sleep, experiencing vivid dreams while falling asleep, waking up feeling unrefreshed and age > 35 years. The prevalence rates of sleep complaints and EDS in this community-based study is high, although this does depend directly on the criteria used to define insomnia and EDS. Recognition of risk factors for EDS may help to identify and treat those affected.