Serum FSH levels were elevated (21.7 IU/l) compared to normal age-matched healthy male controls and patients with non-mosaic Klinefelter syndrome, and inhibin B levels were low-normal, in contrast to the usually undetectable inhibin B levels in adult Klinefelter patients.
Despite normal T concentrations, the KS boys displayed from the age of 13 y elevated serum FSH and LH levels, and exaggerated gonadotropin responses to gonadotropin-releasing hormone.
When non-KS oligo-azoospermic patients were classified according to histology [Sertoli cell-only (SCO), n = 18 or non-Sertoli cell only (non-SCO), n= 18] and compared to KS patients, the hormonal pattern did not differ between SCO and non-SCO subjects, but levels in KS patients were significantly different for FSH, inhibin-B and the FSH/inhibin-B ratio.
Three patients presented Klinefelter syndrome and three a partial androgen insensitivity syndrome (PAIS) as a result of p.Ala646Asp and p.Ala45Gly mutations of the androgen receptor gene.
We wanted to describe X-chromosome inactivation patterns and the AR polymorphism and correlate these to clinical findings in KS in a cross-sectional study.
Our findings demonstrated that the AR-qPCR technique is a simple and reliable screening method for diagnosis of patients with Klinefelter syndrome or other chromosomal disorders involving an aberrant number of X-chromosomes.
The relationship of genetic features of the X chromosome, including parental origin of X chromosomes, the CAG repeat length of the androgen receptor (AR) gene, and X inactivation with progression of pubertal development, growth and testicular function in KS boys.
The undetectable levels of serum AMH and testosterone levels indicate a lack of functional testicular tissue, for example, that in patients with anorchia or severe Klinefelter syndrome suffering from impaired spermatogenesis.
However, in cases with negative TESE only smoking was identified as a predictive factor for negative sperm retrieval and was established as a risk factor.<b>Abbreviations:</b> AZF: azoospermia factor; BMI: body mass index; Crypt: cryptozoospermia; FSH: Follicle-Stimulating Hormone; ICSI: intracytoplasmic sperm injection; IU: international unit; KS: Klinefelter syndrome; LH: Luteinizing Hormone; mL: milliliter; NOA: non-obstructive azoospermia; OA: obstructive azoospermia; T: testosterone; TESA: testicular sperm aspiration; TESE: testicular sperm extraction.
The percentage of microdeletions in KS patients was lower than in NOA patients, suggesting that AZF microdeletions and KS do not have a causal relationship and that Y chromosome microdeletions are not a genetic factor linked to KS.
Serum AMH is low in infants with hypogonadotrophic hypogonadism (and increases with FSH treatment), in patients with primary hypogonadism from early postnatal life and in Klinefelter syndrome from midpuberty.
Expression patterns of DLK1 and INSL3 identify stages of Leydig cell differentiation during normal development and in testicular pathologies, including testicular cancer and Klinefelter syndrome.
In a small percentage of the study population, there was a statistically significant association between bilateral and persistent cryptorchidism and genetic alterations, including Klinefelter syndrome and INSL3 receptor gene mutations.
We review here the current knowledge of the role of TLR7 in SLE, and recent evidence demonstrating that TLR7 escapes from X chromosome inactivation in pDCs, monocytes, and B lymphocytes from women and Klinefelter syndrome men.
This finding supports the hypothesis that enhanced TLR7 expression owing to biallelism contributes to the higher risk of developing SLE and other autoimmune disorders in women and in men with Klinefelter syndrome.