Offenders with intellectual disabilities
John C. Gunn, Pamela J. Taylor in Forensic Psychiatry, 2014
Early research findings in XYY syndrome concluded that affected individuals had an exceptionally aggressive and violent behavioural profile and were predisposed to criminal activities (Sandberg et al., 1961; Jacobs et al., 1965; Hook, 1973). These conclusions were based on findings in psychiatric and penal institutions, with inherent sample biases. Assumption of a direct relationship between the extra male chromosome and criminality oversimplifies the genotype–phenotype relationship. Theilgaard (1984), in a true community sample, found little difference in violence or anti-social behaviour between XYY, XXY and healthy control men; although the XXY men had more often been arrested, they had not more often been convicted. The XYY men reported more difficulties in childhood, including teasing or challenge by other children on account of their size. Ratcliffe (1999) concluded that there is a moderate, but important, increased incidence of antisocial behaviour in XYY, but this is by no means invariable, and is not a simple or inevitable effect of having an extra Y chromosome. Society’s response to the large physical stature, intellectual disability, and tendency to impulsivity of affected individuals all operate as intermediary risk factors.
Scientific Basis of Male Hypogonadism
Anthony R. Mundy, John M. Fitzpatrick, David E. Neal, Nicholas J. R. George in The Scientific Basis of Urology, 2010
An extra Y chromosome from paternal meiosis results in 47,XYY syndrome, occurring in about 0.1% of newborn males. There are few clinical signs other than a relatively tall stature. Testicular function is mildly impaired with normal Leydig cell function, and thus the levels of testosterone and LH are within reference range. Although, most patients are fertile, a proportion may be azoo-spermic because of germinal epithelium maturation arrest. Serum FSH levels are usually increased, and cognitive abilities may be reduced in some men. It was originally thought that patients with 47,XYY syndrome have aggressive behavior (38), but there has been no consistent evidence to support this notion.
Genetic Causes of Male Infertility
Botros Rizk, Ashok Agarwal, Edmund S. Sabanegh in Male Infertility in Reproductive Medicine, 2019
47, XYY syndrome is characterized by the presence of an extra Y chromosome and is estimated to present in around 1/1,000 newborn males. However, up to 85% of XYY males are undiagnosed [26]. The common presentations of XYY syndrome include macrocephaly, macro-orchidism, hypotonia, tall stature, and autistic spectrum disorders [27]. Generally, men with XYY syndrome are fertile. There are divergent data on the link between XYY syndrome and increased sperm sex chromosome aneuploidy [28].
Clinical aspects of infertile 47,XYY patients: a retrospective study
Published in Human Fertility, 2019
Parnaz Borjian Boroujeni, Marjan Sabbaghian, Ahmad Vosough Dizaji, Shabnam Zarei Moradi, Navid Almadani, Faranak Mohammadpour Lashkari, Mohamad Reza Zamanian, Anahita Mohseni Meybodi
Generally, 47,XYY syndrome is not a hereditary anomaly but usually occurs as a random mistake in chromosome segregation during spermatogenesis and results in the production of sperm with an extra copy of the Y chromosome which could lead to a child from a father with 47,XYY having an extra Y chromosome in all cells of his body. In some cases, adding the extra Y chromosome is due to non-disjunction in cell division during post-zygotic mitosis in the early development of the foetus and produces the mosaic karyotype 46,XY/47,XYY (Robinson & Jacobs, 1999).
Related Knowledge Centers
- Cytogenetics
- Fertility
- Heredity
- Karyotype
- Spermatogenesis
- Y Chromosome
- Aneuploidy
- Genetic Disorder
- Learning Disability
- Speech–Language Pathology