Klinefelter's syndrome

Klinefelter's syndrome is the most common genetic cause of human male infertility, but many cases remain undiagnosed because of substantial variation in clinical presentation and insufficient professional awareness of the syndrome itself. Early recognition and hormonal treatment of the disorder can substantially improve quality of life and prevent serious consequences. Testosterone replacement corrects symptoms of androgen deficiency but has no positive effect on infertility. However, nowadays patients with Klinefelter's syndrome, including the non-mosaic type, need no longer be considered irrevocably infertile, because intracytoplasmic sperm injection offers an opportunity for procreation even when there are no spermatozoa in the ejaculate. In a substantial number of azoospermic patients, spermatozoa can be extracted from testicular biopsy samples, and pregnancies and livebirths have been achieved. The frequency of sex chromosomal hyperploidy and autosomal aneuploidies is higher in spermatozoa from patients with Klinefelter's syndrome than in those from normal men. Thus, chromosomal errors might in some cases be transmitted to the offspring of men with this syndrome. The genetic implications of the fertilisation procedures, including pretransfer or prenatal genetic assessment, must be explained to patients and their partners.

Clinical review: Klinefelter syndrome--a clinical update

CONTEXT

Recently, new clinically important information regarding Klinefelter syndrome (KS) has been published. We review aspects of epidemiology, endocrinology, metabolism, body composition, and neuropsychology with reference to recent genetic discoveries.

EVIDENCE ACQUISITION

PubMed was searched for "Klinefelter," "Klinefelter's," and "XXY" in titles and abstracts. Relevant papers were obtained and reviewed, as well as other articles selected by the authors.

EVIDENCE SYNTHESIS

KS is the most common sex chromosome disorder in males, affecting one in 660 men. The genetic background is the extra X-chromosome, which may be inherited from either parent. Most genes from the extra X undergo inactivation, but some escape and serve as the putative genetic cause of the syndrome. KS is severely underdiagnosed or is diagnosed late in life, roughly 25% are diagnosed, and the mean age of diagnosis is in the mid-30s. KS is associated with an increased morbidity resulting in loss of approximately 2 yr in life span with an increased mortality from many different diseases. The key findings in KS are small testes, hypergonadotropic hypogonadism, and cognitive impairment. The hypogonadism may lead to changes in body composition and a risk of developing metabolic syndrome and type 2 diabetes. The cognitive impairment is mainly in the area of language processing. Boys with KS are often in need of speech therapy, and many suffer from learning disability and may benefit from special education. Medical treatment is mainly testosterone replacement therapy to alleviate acute and long-term consequences of hypogonadism as well as treating or preventing the frequent comorbidity.

CONCLUSIONS

More emphasis should be placed on increasing the rate of diagnosis and generating evidence for timing and dose of testosterone replacement. Treatment of KS should be a multidisciplinary task including pediatricians, speech therapists, general practitioners, psychologists, infertility specialists, urologists, and endocrinologists.

Klinefelter syndrome

Klinefelter syndrome is the most common sex chromosome disorder. Affected males carry an additional X chromosome, which results in male hypogonadism, androgen deficiency, and impaired spermatogenesis. Some patients may exhibit all of the classic signs of this disorder, including gynecomastia, small testes, sparse body hair, tallness, and infertility, whereas others, because of the wide variability in clinical expression, lack many of these features. Treatment consists of testosterone replacement therapy to correct the androgen deficiency and to provide patients with appropriate virilization. This therapy also has positive effects on mood and self-esteem and has been shown to protect against osteoporosis, although it will not reverse infertility. Although the diagnosis of Klinefelter syndrome is now made definitively using chromosomal karyotyping, revealing in most instances a 47,XXY genotype, the diagnosis also can be made using a careful history and results of a physical examination, with the hallmark being small, firm testes. As it affects 1 in 500 male patients and presents with a variety of clinical features, primary care physicians should be familiar with this condition.

Success of testicular sperm extraction [corrected] and intracytoplasmic sperm injection in men with Klinefelter syndrome

PURPOSE

The aim of this study was to report the successful fertility treatment of men with Klinefelter syndrome using testicular sperm extraction (TESE) and intracytoplasmic sperm injection (ICSI).

METHODS

A total of 42 men with Klinefelter syndrome who underwent 54 TESE procedures were identified. Before TESE, patients with serum testosterone levels less than 15.6 nmol/liter were treated with an aromatase inhibitor. Sperm retrieval rates and results of ICSI, including fertilization and clinical pregnancy, were collected.

RESULTS

Mean pretreatment FSH and testosterone levels were 33.2 IU/liter and 9.8 nmol/liter. During medical therapy, the mean testosterone level rose to 17.0 nmol/liter (P < 0.01). Spermatozoa were found during 39 microdissection TESE procedures, on the day before, or day of oocyte retrieval during a programmed in vitro fertilization cycle. The sperm retrieval rate was 72% (39 of 54) per TESE attempt, and 29 of the 42 different men (69%) had adequate sperm found for ICSI. Thirty-three in vitro fertilization cycles yielded embryos for transfer in the 39 (85%) cycles with sperm retrieved. Eighteen clinical pregnancies have resulted in 21 live births [18 of 39 (46%)]. All children had a normal karyotype.

CONCLUSION

TESE/ICSI is a successful intervention for the majority of patients with azoospermia and Klinefelter syndrome. Sperm retrieval and ICSI success in men with Klinefelter syndrome are comparable with other men with nonobstructive azoospermia treated at our center.

Assessment of sex chromosome aneuploidy in sperm nuclei from 47,XXY and 46,XY/47,XXY males: comparison with fertile and infertile males with normal karyotype

Sex chromosome aneuploidy was assessed in spermatozoa from a 47,XXY male and a 46,XY/47,XXY male using three colour fluorescence in-situ hybridization (FISH) and compared with two control groups. The first group included subjects of proven fertility and the second infertile males with normal constitutional karyotype. The frequencies of XX and YY disomic, XY hyperhaploid and diploid spermatozoa were significantly increased in the 47,XXY male compared to subjects from the two control groups (P < 0.0001). For the 46,XY/47,XXY sample, the same results were observed, except that the incidence of YY disomic spermatozoa did not differ significantly from the rate obtained in infertile patients. The frequency of sex chromosome aneuploidy did not differ significantly between the 47,XXY and the 46,XY/47,XXY males, except for XX disomic sperm nuclei which was higher in the 47,XXY patient. The frequency of chromosome 12 disomy was also increased in the two XXY individuals (0.42 and 0.49% respectively; P < 0.0001). The meiotic abnormalities observed in the two XXY patients arose through segregation errors in XY germ cells. The increased number of meiotic non-disjunctions observed in the germ cells of infertile males may be a common feature of the deficient oligo- or azoospermic testis. Patients with Klinefelter's syndrome with oligozoospermia have an increased risk of both sex chromosome and autosome aneuploidy in their progeny.

Prognostic value of the clinical and laboratory evaluation in patients with nonmosaic Klinefelter syndrome who are receiving assisted reproductive therapy

OBJECTIVE

To characterize clinical and laboratory findings in nonmosaic 47,XXY patients that may help to predict spermatogenetic activity in their testicles.

DESIGN

Prospective study.

SETTING

Assisted reproductive technology program.

PATIENT(S)

Twenty patients with nonmosaic Klinefelter syndrome who underwent testicular sperm retrieval for IVF.

MAIN OUTCOME MEASURE(S)

The correlation between basal FSH, LH and testosterone levels, mean testicular volume, and results of the hCG test and presence or absence of sperm after testicular sperm extraction (TESE).

RESULT(S)

Sperm was found in nine patients (45%). The mean testicular volume was 7.8 +/- 2.5 mL in men with sperm after TESE and 5.6 +/- 1.2 mL in those without sperm after TESE; corresponding testosterone levels were 3.5 +/- 1.2 ng/mL and 1.7 +/- 0.8 ng/mL. Serum levels of FSH and LH did not significantly differ between groups. After the hCG test, the mean serum testosterone level was 16.0 +/- 6.3 ng/mL in men with sperm after TESE and 6.7 +/- 5.6 ng/mL in those without sperm.

CONCLUSION(S)

Testicular volume, testosterone levels, and results of the hCG test are important predictive factors of spermatogenesis in patients with nonmosaic Klinefelter syndrome.

Preliminary results of a prospective study of testicular sperm extraction in young versus adult patients with nonmosaic 47,XXY Klinefelter syndrome

CONTEXT

Testicular sperm extraction (TESE) in adult patients with nonmosaic 47,XXY provides a sperm retrieval rate (SRR) of approximately 50%. Age is the only significant prognostic factor. Whether TESE should be performed in adolescent patients for sperm cryopreservation remains to be determined.

OBJECTIVE

The objective of the study was to compare SRR between young (15-23 y) and adult (> 23 y) patients with 47,XXY, and to determine whether previous androgenic treatment had a deleterious effect.

DESIGN

We designed a prospective comparative study between two groups enrolled in parallel from September 2010 onward.

SETTING

University hospital.

PATIENTS

Forty one patients with nonmosaic 47,XXY karyotype and azoospermia were included. Twenty five patients from 15-22 years of age were assigned to the "Young" group, and 16 patients age 23 years or more, to the "Adult" group.

INTERVENTION

A bilateral testicular open biopsy was performed by a single surgeon. The reproductive biologist who performed TESE was blind to the patient's age. Principal Outcome Measure: The main outcome measure was the SRR. The TESE procedure was considered positive if at least 20 sperm cells could be cryopreserved for intracytoplasmic sperm injection.

RESULTS

SRR was 13/25 = 52% in the Young group and 10/16 = 62.5% in the Adult group, the difference being nonsignificant (P = .73). Ages were 24.3 ± 7.4 years in the 23 cases of positive TESE, and 23.7 ± 7.4 in the 18 cases of negative TESE, the difference being nonsignificant (P = .42). SRR was 9/17 = 52.9% for patients with and 14/24 = 59.1% for patients without previous testosterone (T) treatment, the difference being nonsignificant (P = .98).

CONCLUSIONS

According to the present results, performing TESE at a younger age (15-23 y) in patients with azoospermic nonmosaic 47,XXY Klinefelter did not increase SRR relative to adult patients (25-39 y). Previous replacement treatment with moderate doses of T did not seem to be deleterious for the recovery of sperm cells by TESE.

High fertilization rate with intracytoplasmic sperm injection in mosaic Klinefelter's syndrome

With the introduction of intracytoplasmic sperm injection (ICSI) as a practical successful treatment for male infertility, we are able to offer the procedure to a group of patients who probably could never father a child of their own. From a patient with mosaic Klinefelter's syndrome, sufficient motile sperm for intracytoplasmic sperm injection were obtained from a fresh ejaculate estimated to contain < 100 motile sperm. In the first IVF-ICSI attempt, out of seven oocytes that were collected from the wife, four were mature and were injected by ICSI. Fertilization occurred in all four oocytes but only one cleaved and was transferred to the uterus. Pregnancy test was negative 16 days after ET. In the second treatment cycle four out of eight oocytes were selected for ICSI. All four fertilized, three cleaved at the right time, and two were transferred into the wife's uterus. One embryo was frozen. Pregnancy test 16 days after ET was negative. The high fertilization rate achieved in this case indicates the potential of ICSI to treat extreme male infertility. Its use offers hope to those patients with conditions previously considered to be untreatable.

Assisted reproductive techniques in patients with Klinefelter syndrome: a critical review

OBJECTIVE

To summarize the existing experience with the use and success rate of assisted reproductive techniques (ART), in particular testicular sperm extraction (TESE) and intracytoplasmic sperm injection (ICSI), in Klinefelter patients.

DESIGN

A systematic review of the literature, including all published case reports to date.

PATIENT(S)

Thirty-nine reported successful pregnancies fathered by nonmosaic Klinefelter patients.

MAIN OUTCOME MEASURE(S)

The overall risk of transmitting a chromosomal abnormality to the offspring of Klinefelter patients.

RESULT(S)

In nonmosaic and mosaic Klinefelter patients, chromosomally normal sperm cells can be extracted from testicular tissue and used for ICSI.

CONCLUSION(S)

The application of ART to Klinefelter patients can be recommended as a method to achieve reproduction in this selected infertility patient cohort.

Consensus statement on diagnosis and clinical management of Klinefelter syndrome

Nearly 70 years after its description, Klinefelter syndrome (KS) remains a largely undiagnosed condition. As its clinical presentation may be subtle, many of those affected may be unaware or diagnosed only during evaluation for hypogonadism and/or infertility. In February 2010 an interdisciplinary panel of specialists met in Abano Terme (Padua, Italy) in a workshop on "Klinefelter Syndrome: diagnosis and clinical management". The main aim of this meeting was to discuss several aspects related to the epidemiology, pathogenesis, and evaluation of KS and to develop a consensus defining its early diagnosis and treatment. In the present consensus we have highlighted the features that may prompt the physicians to look after patients with KS both for the syndrome and correlated diseases. We have provided evidences that, during the different phases of life, there might be some advantages in establishing the diagnosis and starting proper follow-up and treatment. The workshop was carried out under the auspices of the Italian Society of andrology and Sexual Medicine (SIAMS).

Fertile offspring from sterile sex chromosome trisomic mice

Having the correct number of chromosomes is vital for normal development and health. Sex chromosome trisomy affects 0.1% of the human population and is associated with infertility. We show that during reprogramming to induced pluripotent stem cells (iPSCs), fibroblasts from sterile trisomic XXY and XYY mice lose the extra sex chromosome through a phenomenon we term trisomy-biased chromosome loss (TCL). Resulting euploid XY iPSCs can be differentiated into the male germ cell lineage and functional sperm that can be used in intracytoplasmic sperm injection to produce chromosomally normal, fertile offspring. Sex chromosome loss is comparatively infrequent during mouse XX and XY iPSC generation. TCL also applies to other chromosomes, generating euploid iPSCs from cells of a Down syndrome mouse model. It can also create euploid iPSCs from human trisomic patient fibroblasts. The findings have relevance to overcoming infertility and other trisomic phenotypes.

Management of Klinefelter syndrome during transition

Klinefelter syndrome (KS) is the most common sex chromosomal disorder in males. Key findings in older adolescents and young men are small testes with variable hypo-androgenism, but almost universal azoospermia, most frequently in combination with a history of learning difficulties and behavior problems. Males with KS may come to medical attention through different medical presentations, given its association with several congenital malformations, and psychiatric, endocrine, and metabolic disorders. Preventive care is to be provided from diagnosis, preferentially through a multidisciplinary approach, including that from an endocrinologist, clinical psychologist or psychiatrist, neurologist, urologist, geneticist, sexologist, and a fertility team. Accurate information about the condition and assessment of associated medical conditions should be offered at diagnosis and should be followed by psychological counseling. Medical treatment during transition into adulthood is focused on fertility preservation and testosterone replacement therapy in the case of hypo-androgenism, and alleviation of current or future consequences of testicular fibrosis. However, more research is needed to determine the need for pro-active testosterone treatment in adolescence, as well as the conditions for an optimal testosterone replacement and sperm retrieval in adolescents and young men with KS. Furthermore, screening for associated diseases such as metabolic syndrome, autoimmune diseases, thyroid dysfunction, and malignancies is warranted during this period of life. The practical medical management during transition and, more specifically, the role of the endocrinologist are discussed in this article.

Update in andrology

CONTEXT

This is an invited review based on a presentation at the 2007 Annual Scientific Meeting of The Endocrine Society.

OBJECTIVE

The objective of the review was to highlight a selection of the most important peer-reviewed papers in andrology published over the last 1-2 yr.

EVIDENCE ACQUISITION

This was a comprehensive survey of all papers published in major endocrinology journals over the last 2 yr augmented by personal knowledge and literature searching as well as an e-mail survey of more than 40 leading andrologists.

EVIDENCE SYNTHESIS

From the list of suggested papers, the findings of a short list considered the most important were reviewed, aiming to focus on findings that influence thinking and practice in the field of andrology.

CONCLUSIONS

Important advances highlighted included establishing genetic paternity for men with Klinefelter's syndrome as a realistic therapeutic option via testicular sperm aspiration coupled with intracytoplasmic sperm injection in vitro fertilization, using population registry linkage data to define the natural history of Klinefelter's syndrome in the community and identifying active cellular uptake mechanisms for SHBG-bound testosterone challenging the quasiaxiomatic status of the free hormone hypothesis. Other important recent contributions reviewed are on testosterone effects on the prostate, hormonal male contraception, possible temporal trends in blood testosterone concentrations in American men, and The Endocrine Society's position papers on testosterone assays and guidelines on testosterone prescribing.

Down syndrome, Turner syndrome, and Klinefelter syndrome: primary care throughout the life span

Down syndrome, Turner syndrome, and Klinefelter syndrome constitute the most common chromosomal abnormalities encountered by primary care physicians. Down syndrome typically is recognized at birth, Turner syndrome often is not recognized until adolescence,and many men with Klinefelter syndrome are never diagnosed. Although each syndrome is caused by an abnormal number of chromosomes, or aneuploidy, they are distinct syndromes with learning disabilities and a predisposition toward autoimmune diseases,endocrinologic disorders, and cancers. Optimal health care requires a thorough knowledge of the unique health risks, psychoeducational needs, functional capabilities, and phenotypic variation associated with each condition. Syndrome-specific health care should complement standard preventive health care recommendations. Checklists and syndrome-specific growth grids should be used. Ongoing communication between specialists and primary care physicians and between pediatric and adult clinicians is essential. Support groups and Internet resources can benefit affected individuals and their families immensely.

Attitudes of parents of Klinefelter boys and pediatricians towards neonatal screening and fertility preservation techniques in Klinefelter syndrome

To evaluate the attitude of parents of Klinefelter syndrome (KS) boys and pediatricians with regard to early detection of KS and fertility preservation, a specific questionnaire investigating the acceptability towards neonatal screening for KS and the use of testicular biopsy and sperm collection was designed. The responses of 49 pediatricians and 18 parents were evaluated. All parents and 67% of the pediatricians consider neonatal screening for KS to be a good option. A total of 83.3% of the parents agree on performing a testicular biopsy in their pubertal KS boy, 72.2% are in favor of banking spermatozoa after masturbation while 77.7% agree on spermatozoa banking after penile vibro-stimulation or rectal electro-stimulation under general anesthesia. Sixty-nine percent of pediatricians would counsel parents and KS adolescents in favor of early detection and cryopreservation of spermatozoa after masturbation, and 71.2% agrees on testicular biopsy to detect spermatozoa or eventually spermatogonial stem cells (SSCs) for cryopreservation in minor KS patients.

CONCLUSION

The majority of KS parents and pediatricians, completing a specific designed questionnaire on fertility preservation modalities, were in favor of neonatal screening of KS. Both sperm collection and SSC collection are highly appreciated by parents and pediatricians, despite the currently experimental character of these fertility preservation strategies.

Association between venous leg ulcers and sex chromosome anomalies in men

We report here two cases of men, aged 46 and 23 years, with refractory chronic venous leg ulcers in association with sex chromosome aberrations: one with a 47,XXY/48,XXXY karyotype (Klinefelter syndrome) and the other with a 47,XYY karyotype (Jacob syndrome). In both patients, the occurrence of leg ulcers was the reason for seeking medical care; their medical history was other-wise unremarkable. Chromosomal analyses were performed due to the unusually young age for development of venous leg ulcers. The pathophysiology behind the occurrence of venous leg ulcers in patients with numerical aberrations of the sex chromosomes is incompletely understood. Involvement of elevated plasminogen activator inhibitor-1 levels in the pathogenesis of venous leg ulcers has been reported in patients with Klinefelter syndrome. Notably, our patient with 47,XXY/48,XXXY presented with androgen deficiency but normal plasminogen activator inhibitor-1 activity.

A practical approach to intersex in the newborn period

Sexual determination is a complex process that occurs in an organized sequential manner. When chromosomal, gonadal, or phenotypic sex determination goes awry,intersexuality develops. Advances in molecular biology have made it easier to understand the various phenotypes that are encountered. It is easy to be overwhelmed when reviewing the testosterone synthesis pathway and the intersex differential diagnosis. This article presents a useful approach to the evaluation of the newborn with ambiguous genitalia.

Use of a highly sensitive quantitative telomerase assay in intracytoplasmic sperm injection programmes for the treatment of 47,XXY non-mosaic Klinefelter men

We evaluated the role of the sensitive quantitative telomerase assay (SQTA) in the management of men with non-mosaic Klinefelter's syndrome (KS). Diagnostic testicular biopsy (DTB) was performed in 24 men with KS. A part of the DTB was stained and the remaining fragment was processed for the SQTA. After 3-18 months, a therapeutic testicular biopsy (TTB) was performed in the same testicle and the recovered specimens were processed to identify spermatozoa. Men with a SQTA outcome equal to 0.00 Units microg-1 protein (n = 7) demonstrated therapeutic testicular biopsy material that was negative for spermatogenic cells. In five men with a SQTA outcome of 8.11-38.03 Units microg-1, the most advanced germ cell was the spermatogonium/primary spermatocyte. In the remaining 12 men, the most advanced spermatogenic cell in the TTB was the spermatozoon. In these men, the SQTA outcome was equal to 25.76-92.68 Units microg-1 protein. Using 39.00 Units microg-1 protein as a cut-off value, the accuracy of the SQTA in identifying men positive for spermatozoa was 91.6%. It appears that the SQTA has a role for identifying non-mosaic KS men who have testicular spermatozoa.

Infertility considerations in klinefelter syndrome: From origin to management

Klinefelter syndrome (KS) is defined as the presence of one or more extra "X" chromosome in a male patient. It affects approximately 1 in 600 newborn males and the most common chromosomal abnormality, leading to male hypogonadism and infertility. There is a lack of data supporting best practices for KS patients' care. In this paper we review controversial issues in KS research ranging from mechanisms of variation in KS phenotype to abnormalities resulting in reduced sperm production to successful sperm retrieval disparities after testicular sperm extraction (TESE). Translation to live birth and offspring health is also examined. Finally, medical therapies used to optimize the hormonal status and chances of fertility in KS patients are reviewed. We will also discuss the experimental spermatogonial stem cell (SSC) treatments, which are considered the future for TESE negative patients.