Klinefelter's syndrome and its variants: a hormonal and chromosomal study

How Successful Is Surgical Sperm Retrieval in Klinefelter Syndrome?

Klinefelter Syndrome (KS) is characterized by the presence of an extra X chromosome. It was first diagnosed in 1942 in a group of azoospermic men. KS is the most common chromosomal abnormality encountered in infertile men and accounts for more than 10% of the causes of azoospermia. Men who are azoospermic may still father children via testicular sperm extraction followed by intracytoplasmic sperm injection (ICSI). This review article summarizes the success rates of the available techniques for surgical sperm retrieval (SSR) in KS including conventional testicular sperm extraction (cTESE) and micro testicular sperm extraction (mTESE), as well as the risks of these procedures for future fertility. The evidence indicates that the SSR rate is as successful in non-mosaic men with KS as those with normal karyotypes, with retrieval rates of up to 55% reported. The influence of different factors that affect the chances of a successful outcome are discussed. In particular, the impact of aneuploidy rate, physical characteristics, co-morbidities, reproductive endocrine balance and the use of different hormone management therapies are highlighted. Evidence is presented to suggest that the single most significant determinant for successful SSR is the age of the patient. The success of SSR is also influenced by surgical technique and operative time, as well as the skills of the surgeon and embryology team. Rescue mTESE may be used successfully following failed TESE in KS patients in combination with hormone stimulation.

Angioimmunoblastic T-Cell Lymphoma in a Patient with Klinefelter Syndrome

Patient: Male, 61

Final Diagnosis: AITL in Klinefelter syndrome

Symptoms: —

Medication: —

Clinical Procedure: Chemotherapy

Specialty: Hematology

LDOC1 Gene Expression in Men With Klinefelter Syndrome

Klinefelter syndrome (KS) results from an extra chromosome X, which is due to the failure of normal chromosomal segregation during meiosis. Patients with KS have gynecomastia, small testes, and azoospermia. Apoptosis is a mechanism responsible for the normal regulation of spermatogenesis. LDOC1 gene is a known regulator of nuclear factor mediated pathway to apoptosis through inhibition of nuclear factor kappa B (NF-kappaB). Furthermore, the transcription factor myeloid zinc finger gene 1 (MZF-1) has been shown to interact with LDOC1 and to enhance LDOC1 activity favoring apoptosis. We investigated the expression of LDOC1 gene mRNA, by quantitative reverse transcription polymerase chain reaction (qRT-PCR), in peripheral blood leukocytes of 13 patients with KS compared to 13 healthy men chosen as controls. LDOC1 expression was higher in 9 of the 13 KS patient compared to normal controls. These finding led us to hypothesize that LDOC1 gene upregulation may play a role in the spermatogenesis derangement observed in patients with KS.

Klinefelter syndrome with low gonadotropin levels

Klinefelter syndrome is usually characterised by the presence of a eunuchoid body habitus and testes that are usually small and firm, with low testosterone, and elevated luteinising hormone and follicle-stimulating hormone levels, consistent with hypergonadotropic hypogonadism. Low levels of gonadotropins in karyotypically proven cases are not expected, they are extremely rare occurrences. We report a case of a patient who was diagnosed to have Klinefelter syndrome (47 XXY) with low gonadotropin levels. The rest of his anterior pituitary hormonal profile was normal with no lesions in the pituitary gland on imaging. He was continued on androgen replacement therapy.

Increased basal and pulsatile secretion of FSH and LH in young men with 47,XXY or 46,XX karyotypes

OBJECTIVE

The regulation of normal sexual maturation and reproductive function is dependent on a precise hormonal regulation at hypothalamic, pituitary, and gonadal levels. The aim of this study was to investigate the neuroendocrine integrity of the pituitary-gonadal axis in patients with primary testicular failure due to supernumerary X chromosomes.

DESIGN

Cross-sectional study.

METHODS

In this study, 7 untreated patients with primary gonadal insufficiency due to SRY-positive 46,XX (n=4) and 46,XXY karyotypes (n=3) aged 18.8 years and 25 age-matched healthy controls participated. Reproductive hormones, testicular size, and overnight LH and FSH serum profiles and overnight urine LH and FSH excretion were determined.

RESULTS

Basal LH and FSH secretion was elevated 6.3- and 25.4-fold respectively in the patients and the amount of LH and FSH secreted per burst were 2.0- and 6.6-fold elevated. We found significantly more LH but not FSH peaks per 24 h, as estimated by the Weibull lambda analysis. There was no difference between approximate entropy ratios or Weibull gamma analyses indicating comparable orderliness and regularity of LH and FSH secretion. Overnight urinary LH and FSH excretion was significantly elevated in patients compared with controls and correlated significantly with calculated total overnight LH and FSH secretion respectively, thus validating deconvolution.

CONCLUSION

In this group of patients with severe hypergonadotropic hypogonadism due to a supernumerary X chromosome, higher basal, pulsatile, and total LH and FSH secretion were associated with significantly more LH peaks per 24 h in comparison with healthy controls. Thus, our data indicate that in patients with Klinefelter syndrome and XX male karyotypes the entire hypothalamic-pituitary-gonadal axis has undergone functional changes.

Ultrastructural studies of spermatozoa from infertile males with Robertsonian translocations and 18, X, Y aneuploidies

BACKGROUND

In order to clarify the relationship between chromosomal rearrangements, sperm morphology and interchromosomal effects (ICE), we studied the spermatogenetic defects in seven infertile Robertsonian translocation carriers.

METHODS

Lymphocyte karyotypes were evaluated using Giemsa-Trypsin-Giemsa banding and fluorescence in-situ hybridization (FISH). Semen analysis was performed by light and transmission electron microscopy. FISH of sperm nuclei was carried out to detect possible ICE.

RESULTS

Lymphocyte karyotype analysis revealed five t(13;14), one t(13;21) and one t(14;22) carriers. Sperm ultrastructural examination highlighted a higher percentage of immaturity, apoptosis and necrosis than in controls. Aneuploidies of gonosomes were detected in sperm from five out of six carriers of Robertsonian translocation, whereas aneuploidy of chromosome 18 was evident in three out of six carriers. The frequencies of diploidy were altered in all cases.

CONCLUSIONS

Since these infertile patients showed severe spermatogenetic impairment from the morphological and meiotic points of view, we recommend detailed sperm ultrastructural and chromosomal analysis before undertaking ICSI cycles in Robertsonian translocation carriers.

Loss of bone mass in patients with Klinefelter's syndrome despite sufficient testosterone replacement

To determine whether testosterone replacement therapy reverses the detrimental effects of hypogonadism on bone density, we measured the total body, lumbar spine and proximal femur bone mineral density (BMD) by dual-energy X-ray absorptiometry in 14 patients with Klinefelter's syndrome on long-term testosterone replacement therapy and compared the results with 14 age- and sex-matched normal controls. Seven of the patients were receiving oral testosterone undecanoate thrice daily (240 mg/day) and the others were having intramuscular testosterone enanthate injections once every 3 weeks (250 mg/injection). Their serum testosterone levels were maintained within the normal limits (10-40 nmol/l). We showed that patients on testosterone replacement had decreased amount of bone density in the left femoral neck when compared with the controls (p < 0.01). Similar decreases were also observed in the left Ward's triangle (p < 0.01) and in the left trochanter (p < 0.05). There were no significant differences in the total body and the lumbar spine measurements in these two groups of subjects. No correlation was found between the BMD values of femur and the duration of testosterone treatment in the patients with Klinefelter's syndrome. The type of testosterone treatment was also not associated with significant differences in BMD. In conclusion, sufficient testosterone replacement with currently available methods does not reverse the decrease in bone mass associated with hypogonadism in patients with Klinefelter's syndrome.

Klinefelter's syndrome associated with systemic sclerosis

A case of systemic sclerosis is reported in a 41-year-old male with Klinefelter's syndrome. The significance of this association to the aetiology and pathogenesis of systemic sclerosis is discussed.

Autonomous cortisol secretion by a metastatic Leydig cell carcinoma associated with Klinefelter's syndrome

We present the case of a 39-year-old man with Klinefelter's syndrome and a metastatic Leydig cell carcinoma in whom autonomous cortisol production induced by the interstitial cell tumor was found. Apart from the Cushing's syndrome the endocrine activity of the tumor was demonstrated by the secretion of estradiol, estrone, alkaline phosphatase, and testosterone. This is, to our knowledge, the first description of a Cushing's syndrome not caused via ACTH production but directly induced by ectopic steroid production. While being resistent to chemotherapy and radiation, the tumor responded favorably to treatment with o,p'-DDD. The reduction of tumor size was accompanied by a continuous decrease of serum markers. The etiology of the tumor is discussed in the light of the hormonal derangement caused by the genetic abnormality of Klinefelter's syndrome.