Follow-up 20 years later of 34 Klinefelter males with karyotype 47,XXY and 16 hypogonadal males with karyotype 46,XY

Summary A 20-year follow-up study of 50 hypogonadal males has been made. Of these 34 had Klinefelter's syndrome with the karyotype 47,XXY and 16 had the karyotype 46,XY. These males have been examined at mean ages of 27 and 37 and in the present study at a mean age of 47. At the first examination the following conditions were found in the Klinefelter males to a significantly higher degree than in the hypogonadal males with 46,XY: immaturity, below average school performance, few or no friends, previous mental illness, little energy and initiative, few or no spare time interests, occupation as an unskilled labourer. Psychological testing showed a full scale IQ of 103 in the Klinefelter males and 115 in the hypogonadal males. The follow-up studies have shown that in spite of these findings the Klinefelter males have managed far better than could have been expected at the time of the first investigation. The improvement in a number of conditions such as mental health, working capacity, social adjustment, relations with other people, and activity level was considerable between the ages of 27 and 37. The present examination shows a further improvement at the age of 47 with the only significant difference between the Klinefelter males and the hypogonadal males with 46,XY being a higher frequency of single Klinefelter males. The present examination also showed that there was no significant difference between the two groups in occupation, working capacity, social adjustment, mental and physical disorders or criminality. The results of the examination at the mean age of 27 would probably have been considerably more favourable for the Klinefelter males if diagnosis had been made in childhood, and information, counselling, support and hormone treatment had been given from an early age. The fact that the great majority of the Klinefelter males have managed quite well in spite of this and that no remarkable differences were found between them and a control group is of great importance for genetic counsellers, especially for prenatal counsellers. Up until now, in 75% of cases in which sex chromosome abnormalities, including Klinefelter's syndrome, have been diagnosed prenatally in Denmark abortion has been induced. We believe this is mainly due to insufficient information about the many positive aspects of the development of individuals with sex chromosome abnormalities.     

Occlusion in 47,XXY (Klinefelter syndrome) men.

Occlusal morphology of permanent dentitions in 29 men with a 47,XXY chromosome complement (Klinefelter syndrome) was determined from dental casts. The results showed that a relatively frequent occlusal anomaly was mesial molar occlusion. Incisal open bite was also more common than in controls. Based on the present and previous observations of occlusal anomalies in various sex chromosome anomaly groups and normal controls, it is suggested that the presence of the Y chromosome in the genome is at least as important as the X chromosome for the development of harmonious occlusal morphology. The tendency towards sexual dimorphism in occlusal phenotype might result from a differential effect of the X and Y chromosomes on cellular activity which leads to different growth patterns.     

Segregation of sex chromosomes into sperm nuclei in a man with 47,XXY Klinefelter’s karyotype: a FISH analysis

Meiotic segregation of the sex chromosomes was analysed in sperm nuclei from a man with Klinefelter’s karyotype by three-colour FISH. The X- and Y-specific DNA probes were co-hybridized with a probe specific for chromosome 1, thus allowing diploid and hyperhaploid spermatozoa to be distinguished. A total of 2206 sperm nuclei was examined; 958 cells contained an X chromosome, 1077 a Y chromosome. The ratio of X : Y bearing sperm differed significantly from the expected 1 : 1 ratio (χ² = 6.96; 0.001 < P < 0.01). Sex-chromosomal hyperhaploidy was detected in 2.67% of the cells (1.22% XX, 1.36% XY, 0.09% YY) and a diploid constitution in 0.23%. Although the frequency of 24,YY sperm was similar to that detected in fertile males, the frequencies of 24,XX, 24,XY and diploid cells were significantly increased. A sex-chromosomal signal was missing in 4.26% of the spermatozoa. This percentage appeared to be too high to be attributed merely to nullisomy for the sex chromosomes and was considered, at least partially, to be the result of superposition of sex-chromosomal hybridization signals by autosomal signals in a number of sperm nuclei. The results contribute additional evidence that 47,XXY cells are able to complete meiosis and produce mature sperm nuclei. Received: 6 November 1996     

Prevalence of Klinefelter's syndrome (47,XXY) in a general male population

In a representative sample of 3,840 males examined for military service chromosome examination was made in those with testes equal to or less than 12 ml and those with a stature equal to or greater than 181 cm, as well as in males not recruited because of physical or mental disability. Testes equal to or less than 12 ml were found in 59 patients (1.45%). Three of these males had a 47,XXY karyotype (5.1%), the prevalence among the total sample of 3,840 being 0.78 per 1,000. Hypogonadal signs, except for gynaecomastia, which was only present in one patient, were found in the saem proportion as in 47,XXY males ascertained in institutions and clinics. The results of EEG investigations were alos similar to those found in psychiatric institutions. The intelligence level was comparatively low; none had an IQ above 100. The personality traits corresponded to those found in institutionalized Klinefelter males.     

Early androgen deficiency in infants and young boys with 47,XXY Klinefelter syndrome

BACKGROUND/AIMS: Klinefelter syndrome (KS) is characterized by the karyotype 47,XXY. In this study, we evaluated the physical and testicular failure phenotypes of infants and young boys with KS. METHODS: The evaluation included auxologic measurements, biologic indices of testicular function, and clinical assessment of muscle tone in 22 infants and young boys with KS, ages 1-23 months. RESULTS: Mean length, weight, and head circumference in SDS were generally within the normal range at -0.3 +/- 1.0, -0.1 +/- 1.4, and 0.0 +/- 1.5, respectively. Mean penile length and testicular volume SDS were -0.9 +/- 0.8 and -1.1 +/- 0.8, indicating significantly reduced penile and testicular size. Mean testosterone levels for the boys < or =6 and >6-23 months were 128 +/- 131 (4.4 +/- 4.5 nmol/l) and 9.5 +/- 7.2 ng/dl (0.3 +/- 0.2 nmol/l), respectively. High-arched palate was observed in 6/17 boys and clinodactyly (5th finger) was observed in 15/16 boys. Hypotonia was evaluated clinically and was noted to be present in 12/17 boys. CONCLUSION: The physical phenotype in infants and young boys with KS (1-23 months old) includes normal auxologic measurements and early evidence of testicular failure. Muscle tone was decreased in most of the boys. Testicular volume and penile length were diminished, indicating early androgen deficiency. The neonatal surge in testosterone was attenuated in our KS population. Thus, infants and young boys with KS have evidence of early testicular failure. The etiology of this failure and the clinical role of early androgen replacement require further study.     

A 47,XXY female with unusual genitalia

A 47,XXY karyotype was found in a 6-year-old girl. The patient had female external genitalia, clitoromegaly, remnants of the ductus mesonephricus, uterus, and gonads in the labia majora which were determined to be testes by histology. Cytogenetic and DNA analyses suggest that the Y chromosome had a normal structure and that both X chromosomes were of maternal origin. The unusual clinical findings in the patient are discussed.Dedicated to Professor Ulrich Wolf on the occasion of his 60th birthday     

45,X/47,XYY mosaicism in a patient with Turner's syndrome

Summary A patient with classical Turner's syndrome and a 45,X/47,XYY mosaicism is described. Each cell line was present in approximately equal amounts in the peripheral blood lymphocytes, while in fibroblasts derived from skin and both gonads only the 45,X karyotype was present. It is suggested that the latter fact is responsible for the patient not having the mixed gonadal dysgenesis syndrome or tumor formation in both streak gonads.     

47,X,i(Xq),Y karyotype in Klinefelter's syndrome

Summary We report the successful use of a new method described by Gosden and Borck (1977) in two cases of anencephaly; according to this method rapidly adhering cells are identified as neural cells of a specific morphology. Although the original method described adherence of cells during the first 20 h, we were able to identify a considerable number of such cells after a delay of three days due to mailing of the amniotic fluid.     

Executive dysfunction and the relation with behavioral problems in children with 47,XXY and 47,XXX

Neuroimaging studies have shown that having an extra X chromosome is associated with abnormal structure and function of brain areas in the frontal lobe, which is crucially involved in executive functioning. However, there is little of knowledge of the type and severity of executive dysfunction, and the impact on emotional and behavioral problems. The present study aims to provide in this. In total, 40 children (23 boys with 47,XXY and 17 girls with 47,XXX) with an extra X chromosome and 100 non‐clinical controls (47 boys and 53 girls) participated in the study. The participants were 9–18 years old. Processing speed and executive functioning were assessed using the Amsterdam Neuropsychological Testbattery (ANT) and the Dysexecutive Questionnaire (DEX). Problems in emotional and behavioral functioning were assessed with the Childhood Behavior Checklist (CBCL). Children with an extra X chromosome showed deficits in inhibition, mental flexibility, sustained attention and visual working memory. Parental report showed high levels of everyday manifestations of executive dysfunction. More severe inhibition difficulties were associated with higher levels of thought problems, aggression and rule breaking behavior. Boys and girls with an extra X chromosome could not be differentiated based on severity of executive dysfunction, however, girls had lower information processing speed than boys. These findings suggest that executive dysfunction may be part of the phenotype of children with an extra X chromosome, impacting the ability to function adequately in everyday life. Furthermore, children with impairments in inhibition may have more problems in regulating their thinking, emotions and behavior.     

Alterations in the time of X chromosome replication induced by 5-azacytidine in a patient with 48,XXXY/47,XXY

It has recently been shown that 5-azacytidine (5-azaC) can induce altered replication patterns of the late-replicating X chromosome in normal female cells. This has been demonstrated by bromodeoxyuridine labelling of cells late in the S phase. In the present study the same method was applied to the lymphocytes of a Klinefelter patient (48,XXXY/47,XXY). Significant 5-azaC-induced changes in the replication of the entire inactive X chromosome, from late to early, were found in the lymphocytes of this patient. These results indicate that hypomethylating agents can not only alter the replication of individual bands, but also change the gross replication schedule of multiple inactive X chromosomes in the presence of a Y chromosome.     

An SRY-negative 47,XXY mother and daughter

Females with XY gonadal dysgenesis are sterile, due to degeneration of the initially present ovaries into nonfunctional streak gonads. Some of these sex-reversal cases can be attributed to mutation or deletion of the SRY gene. We now describe an SRY-deleted 47,XXY female who has one son and two daughters, and one of her daughters has the same 47,XXY karyotype. PCR and FISH analysis revealed that the mother carries a structurally altered Y chromosome that most likely resulted from an aberrant X-Y interchange between the closely related genomic regions surrounding the gene pair PRKX and PRKY on Xp22.3 and Yp11.2, respectively. As a consequence, Yp material, including SRY, has been replaced by terminal Xp sequences up to the PRKX gene. The fertility of the XXY mother can be attributed to the presence of the additional X chromosome that is missing in XY gonadal dysgenesis females. To our knowledge, this is the first human XXY female described who is fertile.