In search for significant cognitive features in Klinefelter syndrome through cross-species comparison of a supernumerary X chromosome

The behavioral characterization of animals that carry genetic disorder abnormalities in a controlled genetic and environmental background may be used to identify human deficits that are significant to understand underlying neurobiological mechanisms. Here, we studied whether previously reported object recognition impairments in mice with a supernumerary X chromosome relate to specific cognitive deficits in Klinefelter syndrome (47,XXY). We aimed to optimize face validity by studying temporal object recognition in human cognitive assays. Thirty-four boys with Klinefelter syndrome (mean age 12.01) were compared with 90 age-matched normal controls, on a broad range of visual object memory tasks, including tests for pattern and temporal order discrimination. The results indicate that subjects with Klinefelter syndrome have difficulty in the processing of visual object and pattern information. Visual object patterns seem difficult to discriminate especially when temporal information needs to be processed and reproduced. On the basis of cross-species comparison, we propose that impaired temporal processing of object pattern information is an important deficit in Klinefelter syndrome. The current study shows how cross-species behavioral characterization may be used as a starting point to understand the neurobiology of syndromal phenotypic expression. The features of this study may serve as markers for interventions in Klinefelter syndrome. Similar cross-species evaluations of standard mouse behavioral paradigms in different genetic contexts may be powerful tools to optimize genotype-phenotype relationships.     

Detection of Klinefelter syndrome by G-banding analysis combined with primed in situ labeling technique

Primed in situ labeling (PRINS) technique is an alternative to in situ hybridization for rapid chromosome screening. We employed triple-color PRINS technique to detect chromosomal abnormalities in Klinefelter syndrome patients diagnosed by G-banding karyotype analysis. Among 1034 infertile male patients, 134 were found to be cytogenetically abnormal, including 70 with chromosomal number abnormalities and 64 with chromosomal structure abnormalities. Among these cytogenetically abnormal patients, 56 were diagnosed as having Klinefelter syndrome. PRINS technique was used on cultured lymphocyte metaphase cells of the Klinefelter syndrome patients; the same result was obtained with G-banding karyotype analysis. PRINS proved to be a rapid and reliable method to detect numerical chromosome abnormalities in peripheral blood lymphocytes in metaphase.     

Rare Case of Monozygotic Twins Diagnosed With Klinefelter Syndrome During Evaluation for Infertility

Although neither Klinefelter syndrome nor monozygotic twins are particularly rare (1/667 male births and 3–4/1000 live births, respectively), the occurrence of both in the same pregnancy (ie, identical twins with Klinefelter syndrome) is exceedingly rare and has only been reported three times previously in the literature. This report describes the fourth ever reported case of monozygotic twins with Klinefelter syndrome (who presented to our male fertility clinic with failure to conceive) and sheds interesting light on the reproductive concordance observed with this rare clinical entity. To our knowledge, this is the first reported case of monozygotic twins with Klinefelter syndrome that describes the infertility workup and outcomes of microsurgical testicular sperm extraction.Key words: Klinefelter syndrome, Microsurgical testicular sperm extraction, Azoospermia, Sertoli only syndrome, Germ cell aplasiaKlinefelter syndrome, the most common sex chromosome disorder in men, is the clinical result of an additional X chromosome in human males. This syndrome, which affects an estimated 1 in 667 live male births, most commonly manifests as 47,XXY, but may also take the form of 46,XY/47,XXY (Klinefelter mosaicism), 48,XXXY, or 49,XXXXY.¹ Typical clinical manifestations of the syndrome include primary infertility, atrophic testes, hypergonadotropic hypogonadism, gynecomastia, eunuchoidism, and decreased facial and body hair.¹ This condition often goes undiagnosed in prepubertal boys, and even in adult men, despite the physical hallmarks of the syndrome; many cases come to light only during the evaluation of primary male factor infertility. The andrologist, therefore, plays a central role in the diagnosis, work-up, and management of men with Klinefelter syndrome.With an incidence approximately twice that of Klinefelter (3–4 per 1000 live births worldwide),² monozygotic (identical) twinning occurs when one fertilized egg splits and divides into two embryos. Monozygotic twins have been observed with various karyotypic abnormalities, including trisomy 21,³ trisomy 18,⁴ and trisomy 13.⁵ However, the presentation of monozygotic twins with Klinefelter syndrome (a fertilized egg with a 47, XXY karyotype splitting to produce identical embryos with Klinefelter syndrome) is exceedingly rare. In this report, we discuss one case of identical twin brothers diagnosed with Klinefelter syndrome at our fertility clinic (Glickman Urological & Kidney Institute, Cleveland, OH) as part of a work-up for inability to conceive.     

Syndrome de Klinefelter et microinjections intraovocytaires de spermatozoïdes (revue de la littérature)

Historically, Klinefelter’s is the typical clinical form of secretory azoospermia with no hope of achieving biological paternity. However, ICSI, either from ejaculated sperm or following testicular sperm extraction, have been recently applied to patients with Klinefelter’s syndrome. Papers published until June 2002 have reported microinjections with ejaculated sperm in 9 cases of Klinefelter’s syndrome with extreme oligospermia with the following overall results: 79 mature oocytes, 52 fertilized oocytes, 31 embryos, 18 transferred embryos, 6 pregnancies, 5 births, or from testicular spermatozoa, in 93 cases, with the following results: 347 oocytes, 193 fertilized oocytes, 149 embryos, 78 embryos transferred out of 37 cycles, 24 clinical pregnancies and 2 positive pregnancy tests, and 32 births. Although a publication bias was very likely (successful attempts were published, failed attempts were probably not published), these results were unexpected based on the traditional view on Klinefelter’s syndrome. The rate of aneuploid spermatozoa also appeared to be lower than expected. The real proportion of Klinefelter patients in whom spermatozoa with a good potential for embryonic development can be retrieved and the means of identifying these patients remain to be established.     

The specific mitochondrial DNA polymorphism found in Klinefelter's syndrome

Hypervariable segments of mitochondrial DNA (mtDNA) (HV1 and HV2) were analyzed in Klinefelter's syndrome and compared to normal population data. One pair of samples consisting of a Japanese mother and affected son with Klinefelter's syndrome (involved in a criminal case), and seven unrelated DNA samples from Caucasian Klinefelter males (two involved in criminal cases and five diagnosed) were collected in Japan and the United States. The diagnosis of Klinefelter's syndrome was established previously by multiplex XY-STR typing detecting two X alleles and one Y allele in the samples. Haplotype analysis of the mtDNA sequence in Klinefelter males was found to be identical, unique, and specific, as it was not found in the normal population. Astonishingly, family data exhibited that the haplotype of the mtDNA in the son was apparently different from the mother's, suggesting that the mtDNA of Klinefelter male would not be inherited from mother to son. Our data indicate that possible interaction of the sex chromosome and the mtDNA exists, and suggests that the specific mtDNA haplotype could cause the abnormal cell to fertilize and reproduce itself.     

Proteomic analysis of amniotic fluid in pregnancies with Klinefelter syndrome foetuses

Klinefelter syndrome is a sex chromosomal abnormality (47, XXY karyotype), occurring approximately in 1 in 1000 male live births. In the present study proteomic analysis was performed in twelve 2nd trimester amniotic fluid samples, eight coming from pregnancies with normal males and four with Klinefelter syndrome foetuses, as shown by routine prenatal cytogenetic analysis. Samples were analysed by 2-DE, coupled with MALDI-TOF-MS analysis. Three proteins (Ceruloplasmin, Alpha-1-antitrypsin and Zinc-alpha-2-glycoprotein) were found to be up-regulated in samples obtained from pregnancies with Klinefelter syndrome foetuses, whereas four proteins (Apolipoprotein A-I, Plasma retinol-binding protein, Gelsolin, and Vitamin D-binding protein) were down regulated when compared to proteins detected in samples from normal foetuses. The differential expression of Ceruloplasmin, Apolipoprotein A-I and Plasma retinol-binding protein was further confirmed by immunoblotting. Since these proteins are likely to cross the placenta barrier and be detected in maternal plasma they could be used as biomarkers for the non-invasive prenatal diagnosis of Klinefelter syndrome.     

Estrogen and progesterone receptors in gynecomastia

The etiology of gynecomastia is unknown. There seems to be no increased incidence of malignancies in patients with idiopathic gynecomastia; however, patients with Klinefelter syndrome exhibit an increased incidence of malignancy. The authors reviewed the results of 34 patients with gynecomastia diagnosed in adolescence who, following initial evaluation, had a mastectomy. The estrogen and progesterone receptors were analyzed in these patients. Three of the patients were diagnosed with Klinefelter syndrome. These three patients exhibited elevated amounts of estrogen and progesterone receptors. None of the patients who were not diagnosed with this syndrome demonstrated significant elevation of their estrogen or progesterone receptors. The presence of elevated estrogen and progesterone receptors in patients with Klinefelter syndrome provides a potential mechanism by which these patients may develop breast neoplasms. The absence of elevated estrogen and progesterone receptors in patients with idiopathic gynecomastia may serve to clarify why these patients' disease rarely degenerates into malignancy.     

Patent ductus arteriosus and microdeletion 22q11 in a patient with Klinefelter syndrome

We describe an uncommon association of deletion 22q11 in a patient with Klinefelter syndrome. Even though congenital heart defects (CHD) are not associated with Klinefelter syndrome, further investigation of this patient with patent ductus arteriosus showed a microdeletion of chromosome 22q11.2. While this finding may be coincidental, it is important to further evaluate patients when the clinical features are suggestive of a secondary abnormality.     

Detection of chromosomal abnormalities using cordocentesis]

Four cases of cytogenetic prenatal diagnosis of fetuses with chromosomal aberrations are presented: (1) the Patau syndrome; (2) and (4) the Down syndrome; (3) the Klinefelter syndrome. Cordocentesis has been shown to be expedient for rapid and accurate determination of fetus karyotype. Indicative for cytogenetic examination were ultrasonic data, maternal age, the values of AFP, HGG and nonconjugated estreol in maternal serum. Comparison of ultrasonic examination of fetuses with the data on abortus autotopsia was undertaken. The results demonstrate importance of ultrasonic, cytogenetic, biochemical and morphological research in prenatal malformation diagnosis.     

Unusual small supernumerary marker chromosome (sSMC) 9 in a Klinefelter patient

Small supernumerary marker chromosomes (sSMC) are small additional chromosomes characterizable for their origin only by molecular cytogenetic approaches. sSMC have been reported previously in four types of syndromes associated with chromosomal imbalances: in approximately 150 cases with Turner syndrome, 26 cases with Down syndrome and only one case each with Klinefelter syndrome and "Triple-X"-syndrome. Here we report the second case with an sSMC detected in addition to a Klinefelter karyotype. Molecular cytogenetics applying centromere-specific multicolor FISH (cenM-FISH) and a specific subcentromere-specific (subcenM-FISH) probe set characterized the sSMC as a dic(9)(:p12-->q11.1::q11.1--> p11.1:). The reported patient was described with hypogonadism, gynaecomastia plus a bronchial carcinoma. The patient's clinical features are discussed in connection with other Klinefelter cases and possible consequences of presence of the sSMC(9). Furthermore, a suggestion is made for the mode of sSMC-formation in this case.     

A family with a satellited Yq chromosome

Summary A large pedigree with a satellited Yq chromosome is described, Q, C, and NOR banding were performed. Family C proband suffers from a Klinefelter syndrome.     

X-chromosome polysomy in the male

Summary A review of 569 male patients with X-chromosome polysomies (544 Klinefelter and 25 patients with other types of X-chromosome polysomy) is presented here. These patients were detected among the 77000 persons karyotyped in the Leuven cytogenetic center between the years 1966 and 1987. In the group of 544 Klinefelter patients special attention was paid to (1) the age at diagnosis, (2) social and marital status of the postpubertal males, (3) physical and intellectual abilities of the prepubertal boys, (4) delineation of the concurrence of Klinefelter syndrome and fragile X syndrome, and (5) the frequency of malignancies. In 25 patients with other X-chromosome polysomies (2 n48 chromosomes) genotype/phenotype correlation is reviewed, especially for the patients with 48,XXYY and 49,XXXXY karyotypes. Finally, double aneuploidy and rare structural X-chromosome aberrations are briefly discussed.     

49,XXXXY syndrome with diabetes mellitus

49,XXXXY syndrome is a rare sex chromosome aneuploidy and characterized by mental retardation, skeletal defects, craniofacial anomalies and hypogonadism. The increased frequency of diabetes mellitus in patients with Klinefelter syndrome and other types of X-chromosome polysomy has been reported, but no cases of diabetes mellitus in adult with 49,XXXXY syndrome have been reported so far. We report an 18-year-old patient with 49,XXXXY syndrome accompanying diabetes mellitus.     

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.     

Naissance après ICSI réalisée avec sperme éjaculé, congelé, chez un jeune patient de 21 ans porteur d’un syndrome de Klinefelter homogène

Klinefelter’s syndrome is one of the main genetic causes of male infertility, as it is diagnosed in 11% of patients with azoospermia and 4% of infertile men. This study reports a birth after ICSI performed with ejaculated sperm from a 21-year-old man with homogeneous nonmosaic Klinefelter’s syndrome discovered during assessment of infertility for severe oligozoospermia. Three ICSI were performed for this couple over an 18-month period. Pregnancy was not achieved after the first and second ICSI with fresh ejaculated sperm. At the third ICSI, the patient presented proven azoospermia on the day of the attempt, and frozen-thawed ejaculated spermatozoa were therefore used. A pregnancy was obtained after the transfer of 3 grade A embryos with the birth of a healthy girl. The authors highlight the value of repeated preventive sperm cryopreservation when ejaculated spermatozoa are available in all cases of severe oligozoospermia or cryptozoospermia. They also evaluated the quality (DNA fragmentation, ploidy) of the frozen/thawed spermatozoa.     

Clinical, hormonal and sonographic features of the identical twins with Klinefelter syndrome--a case report

A rare case of Klinefelter syndrome in identical twins is reported. Hormonal levels before and after hCG administration and testicular artery Doppler flow measurements are presented.     

Case of XXXXY syndrome. Development throughout adolescence and endocrine aspects

49,XXXXY syndrome is a very rare condition that is associated with a considerable more severe phenotype than classic 47,XXY Klinefelter syndrome. We present a patient with 49,XXXXY syndrome, who was first presented to an endocrinological unit at the age of 12.5 years with prepubertal genitalia. He was then lost from follow-up and showed clear clinical and biochemical signs of hypergonadotropic hypogonadism when presenting again at the age of 16 years. The patient was started on testosterone replacement therapy. This case is reported to underline the need for thorough endocrinological follow-up examinations in males with X polysomies.