Males with an XYY sex chromosome complement

The Role of Number of Copies, Structure, Behavior and Copy Number Variations (CNV) of the Y Chromosome in Male Infertility

The World Health Organization (WHO) defines infertility as the inability of a sexually active, non-contracepting couple to achieve spontaneous pregnancy within one year. Statistics show that the two sexes are equally at risk. Several causes may be responsible for male infertility; however, in 30–40% of cases a diagnosis of idiopathic male infertility is made in men with normal urogenital anatomy, no history of familial fertility-related diseases and a normal panel of values as for endocrine, genetic and biochemical markers. Idiopathic male infertility may be the result of gene/environment interactions, genetic and epigenetic abnormalities. Numerical and structural anomalies of the Y chromosome represent a minor yet significant proportion and are the topic discussed in this review. We searched the PubMed database and major search engines for reports about Y-linked male infertility. We present cases of Y-linked male infertility in terms of (i) anomalies of the Y chromosome structure/number; (ii) Y chromosome misbehavior in a normal genetic background; (iii) Y chromosome copy number variations (CNVs). We discuss possible explanations of male infertility caused by mutations, lower or higher number of copies of otherwise wild type, Y-linked sequences. Despite Y chromosome structural anomalies are not a major cause of male infertility, in case of negative results and of normal DNA sequencing of the ascertained genes causing infertility and mapping on this chromosome, we recommend an analysis of the karyotype integrity in all cases of idiopathic fertility impairment, with an emphasis on the structure and number of this chromosome.

The Biology and Evolution of Mammalian Y Chromosomes

Mammals have the oldest sex chromosome system known: the mammalian X and Y chromosomes evolved from ordinary autosomes beginning at least 180 million years ago. Despite their shared ancestry, mammalian Y chromosomes display enormous variation among species in size, gene content, and structural complexity. Several unique features of the Y chromosome--its lack of a homologous partner for crossing over, its functional specialization for spermatogenesis, and its high degree of sequence amplification--contribute to this extreme variation. However, amid this evolutionary turmoil many commonalities have been revealed that have contributed to our understanding of the selective pressures driving the evolution and biology of the Y chromosome. Two biological themes have defined Y-chromosome research over the past six decades: testis determination and spermatogenesis. A third biological theme begins to emerge from recent insights into the Y chromosome's roles beyond the reproductive tract--a theme that promises to broaden the reach of Y-chromosome research by shedding light on fundamental sex differences in human health and disease.

Nonmosaic 47,XYY syndrome presenting with male infertility: case series

In this study, we describe nine patients with 47,XYY presenting with male infertility. All patients were subjected to history taking, clinical examination, duplex ultrasonographic examination of the scrotum, endocrinological investigations and cytogenetic analysis of peripheral lymphocytes. Two patients tried intracytoplasmic sperm injection (ICSI). Our results showed that seven patients were oligospermic and two patients were azoospermic. Bilateral varicocele was detected in seven patients. The hormonal levels in the majority of the patients were within normal range. Two patients showed improvement after varicocelectomy. The wife of one of the oligospermic patients became successfully pregnant after the first trial of ICSI. In conclusion, this report suggests that patients with XYY may present with primary infertility and may show oligospermia and nonobstructive azoospermia. Careful clinical, ultrasonographic, endocrinological and cytogenetic examinations should be a part of their diagnostic work-up for the proper management of these patients. In addition, ICSI may be a hope for some of these patients.

Sex chromosome aberrations and stature: deduction of the principal factors involved in the determination of adult height

Although sex chromosome aberrations are frequently associated with statural changes, the underlying factors have not been clarified. To define the factors leading to the statural changes, we took the following three steps: (1) determination of the mean adult height in nonmosaic Caucasian patients with sex chromosome aberrations reported in the literature (assessment of genetic height potential); (2) assessment of the validity of factors that could influence stature; and (3) correlation of the mean adult height with the effects of specific growth-related factors. The results indicate that the adult height in patients with sex chromosome aberrations may primarily be defined by the dosage effect of pseudoautosomal and Y-specific growth genes, together with the degree of growth disadvantage caused by alteration of the quantity of euchromatic or non-inactivated region.

A transsexual male with 47,XYY karyotype

Transsexuals are usually found to have a normal chromosome complement. The literature to date documents four transsexuals with 47,XYY pattern. This paper reports a fertile male with major cell line of 47,XYY and a gender identity disorder.

Comparison of adult height between patients with XX and XY gonadal dysgenesis: support for a Y specific growth gene(s)

Adult height was compared between published cases of patients with XX gonadal dysgenesis (XXGD) and those with XY gonadal dysgenesis (XYGD). The mean adult height of XYGD patients (171.0 cm (SD 7.8), n = 27) was significantly greater than that of XXGD patients (164.4 cm (7.7), n = 27) (p less than 0.01). This finding supports the existence of a Y specific growth gene(s) which promotes statural growth independently of the effects of gonadal sex steroids.

Effects of the Y chromosome on quantitative growth: an anthropometric study of 47,XYY males

The aim of the study was to investigate the effects of the Y chromosome on different body and head dimensions of 47,XYY males, and especially its effect on their body proportions. From seven adult 47,XYY males 25 anthropometric measurements were recorded and compared with four male relatives and 42 control males. In most dimensions 47,XYY males were larger than the normal males, the difference being mainly between 0.5 and 1.5 S.D. units. The body proportions of 47,XYY males were found to be similar to those of the normal males when the effect of size was allowed for. It is concluded that the extra Y chromosome in 47,XYY males causes an increase in their growth without affecting the body proportions. This finding suggests that the Y chromosome contains gene(s) which affects growth by increasing its quantitative outcome. This effect may be mediated by a direct action of the Y chromosome on the cells. It also may seem that the Y chromosomal gene(s) influence the development of the sex difference in height and body size.

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.

Sex chromosome aberrations in schizophrenia

Research on sex chromosome aberrations has made considerable progress. There are evidences that possession of an extra X chromosome may affect the mental health of an individual. All the male schizophrenia patients registered during the period of study, who were not under treatment, constituted the patient sample. They numbered two hundered eighty seven. A properly matched control sample of two hundred thirty three healthy persons was also examined. Nuclear sexing and Karyotype was done for (a) all the chromatin positive cases in patient as well as control sample (b) ten per cent cases of normal XY individual's of patient sample(28) and control sample (23) Photography was done for the positive slides. The patients who showed chromation positive XXY pattern were studied further clinically along with Rorschach test and Bhatia battery. The schizophrenics showed more prevalence of chromatin positive than the control sample.

A chromosome survey of a hospital for the mentally subnormal

A cytogenetic survey of 756 resident, but otherwise unselected, mentally retarded patients in a Scottish hospital is reported. The karyotypes of all patients were examined using orcein-stained cells, and those found to be abnormal, other than those with standard trisomy 21, were further investigated using a banding technique. A total of 103 patients were found to have an abnormal chromosome complement, of whom 91 had Down's syndrome (including six with translocations), six had some other autosomal abnormality, and six had an abnormality of the sex chromosome complement, including two with an XXYY complement. Details of the clinical and cytogenetic features are presented.

Pneumoencephalographic and clinical findings of the XYY syndrome

In order to approach the hitherto unknown brain involvement in the XYY syndrome five adult patients with this syndrome were studied clinically and pneumoencephalographically. Clinical manifestations included delayed difficulties of speech and learning, clumsiness, mild intention tremor, muscular hypotonia, convulsions, hyperactivity, distractibility, impulsiveness, weak mental control, psychosexual disturbances and a slight defect of intelligence. All five had committed crimes. Pneumoencephalograms showed general ventricular enlargement of mild or moderate degree. The enlargement of lateral ventricles was unilateral or asymmetrically bilateral. The suprapineal recess of the third ventricle was uniformly enlarged. Small cerebellum and enlarged fourth ventricle were the abnormal findings in the posterior fossa. No cortical abnormalities were found. The clinical and pneumoencephalographic findings suggest a slight non-progressive developmental disorder of the brain resembling the so-called minimal brain dysfunction syndrome. The XYY syndrome appears to be one cause of the male preponderance in minimal brain dysfunction syndrome and criminal psychopathy.

Pituitary-gonadal function in XYY and XXY men identified in a population survey

Evidence on pituitary-gonadal function in XYY subjects has been inconclusive and based, for the most part, on selected samples such as institutionalized individuals or subjects examined for particular behavioural or medical characteristics. We report the results of a double-blind hormonal study of a sample from an entire well-defined birth cohort of men. The starting population included all males born in Copenhagen during the period 1944-1947 comprising 31,436 individuals. Chromosome determinations conducted on 4139 men representing the top 15.9% of the height distribution of the sample identified 12 XYY and 16 XXY men. All the XYY subjects and 14 XXYs consented to participate in an individual case study and were individually matched to XY controls selected from the total sample. The XYY men had significantly higher plasma concentrations of LH, FSH and testosterone than matched XY controls. There were no differences in testicular size and in the reported number of children between the XYYs and control group. XXY men from the same population showed significantly higher LH and FSH, lower concentrations of testosterone, had smaller testes and reported fewer children than their matched controls.

Prenatal cytogenetic diagnosis: first 1,000 successful cases

From February 1969 to August 1976, we studied 1,048 amniotic fluids. Of these, 958 (91.4%) were primarily for prenatal cytogenetic diagnosis. Cytogenetic studies were attempted in 1,021 cases; the diagnosis was successful in 1,000 of these. The failure rate of obtaining a diagnosis from the amniotic fluid cell culture of the first amniocentesis was 5% (50 cases); 29 cases had a repeat tap and successful diagnosis was achieved in all. In 21 cases, a repeat tap was refused. Thus, the overall failure rate of obtaining a final cytogenetic diagnosis was 2.06% (21/1,021). There were 32 fetal losses after amniocentesis including 16 spontaneous second trimester abortions, 7 fetal deaths in utero and 9 stillbirths. In two additional cases, fetal death had occurred before amniocentesis. This number of fetal losses does not exceed the number that would be expected in the same maternal age group without amniocentesis. In our series, the frequencies of trisomy in maternal age groups 40 years and over, 37-39 years, 35-36 years, and under 35 years were 4.5, 3.14, 0 and 0% respectively. These frequencies are comparable to those reported from other prospective prenatal studies and higher than those of retrospective live born studies. Various problems and pitfalls in prenatal cytogenetic diagnosis are discussed.

XYY males. Some clinical and psychiatric aspects deriving from a survey of 1,811 males in hospitals for the mentally handicapped

A survey of 1,811 mentally handicapped males in eighteen hospitals is described. Males discovered with supernumerary Y chromosomes numbered 15, of whom 12 were 47,XYY. Some of the physical, social, psychological and psychiatric findings are described and compared with groups matched for IQ and height. The main psychiatric findings are diminished intelligence, retardation in development of secondary sexual characteristics, and poor emotional control leading to inadequate social adaptive patters which are described and discussed.

Spermatogenesis in an infertile XYY man

Testicular histology and meiosis has been studied in an XYY male patient identified at an infertility clinic. This man was found to have an XYY set chromosome complement in 15% of spermatogonial metaphases. There was no evidence of 2 Y chromosomes at diakinesis but there appeared to be a slight excess of sperm with a fluorescent Y body.

[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.

Chromosomal determinants of intermale aggressive behavior in inbred mice

A behavioral genetic system has been investigated in which the Y chromosome of DBA/1/Bg mice makes an incremental contribution to the adult aggression of B10D1F1 hybrid mice. Crosses with C57BL/10/Bg, C57BL/6/Bg, and DBA/2/Bg have identified a minimum of one incremental and one decremental (suppressor) genetic factor (in addition to the Y chromosome) which are autosomal and which affect the expression of adult intermale aggression in these strains.

Human intelligence: sex differences

An extensive review of the literatureon sex differences in human intelligence leads to the conclusion that there is stron evidence for sex differences in processing both verbal and spatial information. The few genetic studies that there are all point toward a sex-link mode of inheritance of certain spatial abilities.

The XYY syndrome: a study of four subjects and their families

A study of four 47XYY subjects and their families is reported. These subjects were all exceptionally tall; were mostly of good intelligence and from intelligent families; and all had a history of delinquency or criminality, although they came from respectable homes. Evidence is presented, however, to suggest that both adverse environmental influences and constitutional factors other than their supernumary chromosomes nevertheless operated in these cases, indicating that their deviant behaviour need not be directly related to their chromosomal abnormality. The implications of these findings are discussed with respect especially to their bearing on conclusions drawn in the literature on the XYY syndrome.

Thirty-five males with double Y chromosome

Thirty-five males with double Y chromosome were studied. Among the features observed in certain subgroups of these 35 were a more than average height, minor vertebral abnormalities, abnormal seminiferous epithelium, minor EEG abnormalities, and a mean intelligence level significantly below the expected. Fifteen of the 35 were found in institutions for criminals. The frequency of XYY males among 1,500 criminal males was 8·67 per 1,000 compared with 1·24 per 1,000 among 6,455 randomly selected males in the general population. Males with double Y chromosome tended to have more difficulties at school, to be more mentally immature, to be more impulsive than their siblings, and to have more difficulty in making relationships with others.

Studies on the activity of the pituitary-gonadal axis in the XYY syndrome

Results are presented of pituitary gonadotrophic and testicular steroid hormone assays carried out on 11 phenotypic males with a 47, XYY karyotype. These results are compared with those from a control group of normal ambulant males and a group of patients with a 46, XY karyotype who were detained in a maximum security hospital.

Normal male development with Y chromosome long arm deletion (Yq-)

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A case of XYY Down's syndrome confirmed by autoradiography

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