Human genetics. A father's imprint on his daughter's thinking.
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Chromosome Deletion↗
Biomedical subjects
J Scourfield
Publications and source records attributed to J Scourfield.
Genes and social skills.
Evidence for one or more loci on the human X chromosome influencing social cognition was recently presented by Skuse et al. The imprinted locus is only expressed from a paternally inherited X chromosome, which means that boys do not express it because their only X chromosome comes from their mother. This raises the possibility of genetic as well as cultural influences on sex differences in behaviour and cognition. It may also offer some explanation for why boys are more vulnerable to developmental disorders that affect social behaviour, such as autism.
Autistic Disorder↗
Association studies of bipolar disorder at the human serotonin transporter gene (hSERT; 5HTT).
The human serotonin transporter gene (hSERT) is a strong candidate for involvement in the pathogenesis of mood disorder and, using a UK Caucasian case-control sample, Collier et al found a significant association between bipolar disorder and the 12 allele of the VNTR polymorphism in intron 2 of this gene. In a European collaborative sample, Collier et al found a significant association between affective disorder and a functional deletion polymorphism in the promoter of hSERT. We have undertaken association studies using these polymorphisms in a British Caucasian sample comprising 171 DSM-IV bipolar probands, 80 DSM-IV major depression probands and 121 unrelated controls matched to bipolar probands for age, sex and ethnicity. We found no association between the promoter deletion and affective disorder but our findings with the VNTR polymorphism are similar to those of Collier and colleagues: we found a significant excess of the 12 repeat allele in bipolar probands (P = 0.031, one-tall) with a suggestion of a gene dosage effect (using genotypes bearing no 12 repeat allele as baseline, the increased risks conferred by genotypes bearing 12 repeat alleles were: heterozygote, OR = 1.24; homozygote, OR = 1.76). Our findings add to the evidence that variation at or near hSERT influences susceptibility to bipolar disorder in the British Caucasian population.
Adult↗
Imprinted X-linked genes, 'feminine intuition' and the public (mis)understanding of science.
The report of an imprinted locus on the X chromosome influencing social behaviour was taken up with fervour by the media and reported in a way which neglected the reality of multifactorial complexity and the interplay between genetic and environmental contributors to gender differences. We summarize the background scientific details of the study and discuss the media reporting of those findings.
Genetic Linkage↗
The changing prevalence of autistic disorder in a Welsh health district.
A prevalence study of autistic disorder (AD) in childhood was undertaken in a Welsh health district as part of a needs' assessment exercise. The study population were all children resident in the district with dates of birth between 1977 and 1988. Children were identified after a trawl of service providers in health and education and diagnosis was confirmed at a multidisciplinary assessment. An increase in prevalence was found, an observation that has been made in other parts of the world. The increase in prevalence, whether real or administratively apparent, has major implications for service providers in health, education, and social care, in that a larger number of children are being recognised as having a triad of impairments which requires very specific interventions and support from all three agencies.
Autistic Disorder↗
Huntington's disease: psychiatric practice in molecular genetic prediction and diagnosis.
BACKGROUND: Predictive genetic testing for Huntington's disease has been available in Cardiff since 1987 using linked genetic markers, and since 1993 using direct mutation testing, which can also be used as a diagnostic test. During this period there have been numerous referrals that have required liaison with psychiatric services at all stages of the testing programme. METHOD: A series of cases was selected to highlight issues from both genetic prediction and diagnosis that are relevant to psychiatric practice and have arisen during the testing programme. RESULTS: Issues have been raised concerning competence to consent to testing in the context of psychotic illness; depression and suicidal ideation in test candidates; requests for testing from third parties such as psychiatrists, social services and the courts; and testing of children. CONCLUSIONS: As genetic testing becomes possible for more disorders the lessons learned from Huntington's disease will provide valuable guidelines for counselling.
Adolescent↗
Huntington's disease predictive testing: the case for an assessment approach to requests from adolescents.
Adolescents who are actively requesting Huntington's predictive testing of their own accord pose a dilemma to those providing testing. In the absence of empirical evidence as regards the impact of genetic testing on minors, current policy and guidelines, based on the ethical principles of non-maleficence and respect for individual autonomy and confidentiality, generally exclude the testing of minors. It is argued that adherence to an age based exclusion criterion in Huntington's disease predictive testing protocols is out of step with trends in UK case law concerning minors' consent to medical treatment. Furthermore, contributions from developmental psychology and research into adolescents' decision making competence suggest that adolescents can make informed choices about their health and personal lives. Criteria for developing an assessment approach to such requests are put forward and the implications of a case by case evaluation of competence to consent in terms of clinicians' tolerance for uncertainty are discussed.
Adolescent↗
Anorexia by proxy: are the children of anorexic mothers an at-risk group?
Three different presentations of abnormal eating behavior in children of anorexic women are described. The author believes that the various presentations should increase our awareness of such children who may be considered an at-risk group.
Anorexia Nervosa↗
The neural tube origin of ventral root sheath cells in the chick embryo.
The embryonic origin of peripheral nerve Schwann/sheath cells is still uncertain. Although the neural crest is known to be an important source, it is not clear whether the ventral neural tube also contributes a progenitor population for motor axons. We have used the techniques of immunohistochemistry, electron microscopy and quail-chick grafting to examine this problem. Immunohistochemistry with monoclonal antibody HNK-1 identified a cluster of immunoreactive cells in the sclerotome, at the site of the future ventral root. With the electron microscope, nucleated cells could not be seen breaching the basal lamina of the neural tube, exclusively in the region of the ventral root and preceding axon outgrowth. After grafting a length of crest-ablated quail neural tube in place of host chick neural tube, a population of quail cells was found localized to the ventral root exit zone, associated with the ventral root axons. Taken together, these observations support the possibility of a neural tube origin for ventral root sheath cells, although we found no evidence for a more extensive migration of these cells. The ventral root cells share certain phenotypic traits, such as HNK-1 immunoreactivity, with neural-crest-derived Schwann cells, but are not necessarily identical to them. We argue that while they may help motor axons to exit the neural tube at the correct position, they are unlikely to guide axons beyond the immediate vicinity of the neural tube.
Animals↗
Substance abuse, comorbidity, and sensation seeking: gender differences.
Two hundred sixty-two probands and 261 of their relatives with DSM-III-R diagnoses of drug and alcohol abuse and/or anxiety disorders completed the Zuckerman Sensation Seeking Scale. It was hypothesised that subjects with both substance abuse disorders and comorbid anxiety disorders would have lower sensation-seeking profiles than subjects with substance abuse alone. This was confirmed in women, with thrill- and adventure-seeking scores showing significant differences between pure substance abusers and those with a comorbid anxiety disorder, lending support to theories that substance abusers are a heterogeneous group. In men, there were fewer significant differences between diagnostic groups. If substance abusers are indeed a heterogeneous group, with some motivated by high sensation-seeking needs, a better understanding of these motivations can lead to more effective strategies of prevention and treatment, according to etiology.
Adult↗