The XYY syndrome: reality or myth?

XYY chromosome anomaly and schizophrenia

Sex chromosome anomalies have been associated with psychoses, and most of the evidence is linked to the presence of an additional X chromosome. We report a patient with XYY chromosome anomaly who developed schizophrenia.

Growth during puberty in the XYY boy

The availability of a cohort of eight unselected XYY boys identified by newborn cytogenetic screening has enabled their growth to be studied longitudinally in comparison with controls from the same population. While no difference had been found in dimensions at birth, increased height velocity in childhood resulted in the XYY boys being 7.6 cm taller at the onset of their pubertal growth spurt. Increased intensity of growth at puberty with a peak height velocity of 10.6 cm/year contributed to their adult height of 188.1 cm. XYY boys showed twice the male-female difference in height implying that genes on the Y chromosome exert a quantitative effect on the sexual dimorphism of growth.

[Genetically determined variability in mental and emotional development (author's transl)]

Human beings develop in biologically determined phases: During certain periods of life, sensitivity for learning specific tasks is increased. For successful completion of the learning process, however, adequate offers from the environment are necessary. Within the limits of this general rule, considerable genetically determined, interindividual differences are observed. The ability to develop faster or slower in certain phases of life, - strong and weak points, - specific chances and liabilities are distributed unevenly. The art of education consists in adjusting offers for learning to these individual differences. In addition to the cognitive field, requirements for emotional and social learning should not be neglected. Research on biologic maturation, on its interaction with offers from the environment, and on genetic variability will have to include in future increasingly neurobiologic concepts and methods.

Sex chromosome disorders

A critical and comprehensive review of the major sex chromosome disorders. The introduction briefly outlines the cytogenetic background to these disorders and refers to earlier reviews. The paper then reviews the clinical and psychiatric aspects of the various chromosome disorders. Male and female phenotypes are dealt with separately, with emphasis on psychological and behavioural manifestations including antisocial behaviour. Medico-legal implications are also reviewed, as are the implications for research.

Follow-up of 11 XYY males with impulsive and/or sex-offending behaviour

Eleven behaviourally abnormal XYY males who had been treated in a structured combined programme of antiandrogen medication and counseling were followed up 1 year after cessation of the programme. Behavioural ratings were made in each of 5 categories: assault against people, destructiveness against things, threatening behaviour, stealing, and self-harming. On examining the follow-up findings, therapeutic success appeared questionable.

Plasma noradrenalin and dopamine-beta-hydroxylase during behavioral testine of sexually deviant XYY and XXY males

In a behavior study of a sexually deviant XYY and XXY male, who were both murderers, plasma noradrenaline (NAA), dopamine-beta-hydroxylase (DBH) were determined radioenzymatically under resting conditions and during exertional and emotional stress. Under a physical sork load on the bicycle ergometer both had normal plasma NA and DBH levels. During emotional stress both had NA increases of the same magnitude. During an arithmetic test NA values did not increase more than expected for the sitting position.

Follow-up till age 3--4 of unselected children with sex chromosome abnormalities

Follow-up examination of 15 unselected children with aneuploid sex chromosome abnormalities has been made till between the age of 2 1/2 and 5 years. The mental development of the 15 children was in all cases within the normal range, but there was a tendency to some differences compared with their siblings.

[Sex chromosome aberration screening among male psychiatric patients (author's transl)]

The authors report of sex chromosome aberration screenings among the patients of the male psychiatric department, University Medical School, Pecs. 310 patients were investigated. The X-chromatin was detected in buccal smears with thionin-staining and the Y-chromatin in peripheric blood smears with quinacrin-staining by the help of fluorescentoptical technique. Two Klinefelter-patients and one YY-patient were diagnostized. The Klinefelter-patients were psychopaths and mentally subnormal, the YY-patient was a paranoid schizophrenic. The incidence of Klinefelter syndrome is 0.64%, that of the YY syndrome is 0.32%. Mental relations of sex chromosome aberrations are discussed in detail.