Endocrine Abstracts

Introduction: Klinefelter syndrome is a sex chromosomal aneuploidy caused by an addition of X chromosome in males (47,XXY). 48,XXXY is a rare variant of this syndrome which is characterised by the presence of two additional X chromosomes in males and is estimated to occur in 1/50 000 male births. Here we describe a rare case of a 48, XXXY Klinefelter’s variant in a 17 years old patient revealed by an intellectuel development delay.

Case Report : The patient was a 17 years old male, born to non-consanguinous parents after full term normal delivery. He was undergoing psychotherapy for intellectuel development delay and referred to our department for etiologic research. Clinical examination revealed a normal facial morphology with a tall stature; the presence of a delayed puberty and a micropenis are the significant features observed in the present case. The hormonal assessment was in favor of a hypergonadotropic hypogonadism profil. The cytogenetic analysis revelealed a variant of klinefelter syndrome: 48,XXXY.

Discussion: The presence of one or more additional X chromosome(s) above the typical 46,XY in males leads to testicular dysgenesis and hypergonadotropic hypogonadism, and thus, 48,XXXY is often considered a variant of Klinefelter syndrome (47,XXY) because of these shared features. However, patients with this variant have an increased risk of congenital malformations, additional medical problems, more complex psychological involvement and thus a more severe prognosis compared to patients with 47,XXY The intellectuel problem in our patient indicate the effect of the two extra X chromosomes, wherein each extra X is associated with an IQ decrease of approximately 15-16 points. Early confirmation of the diagnosis is essential for therapeutic management and genetic counselling.

References: 1. A. Venkateshwari et al. Clinical and Behavioural Profile of a Rare Variant of Klinefelter Syndrome-48, XXXY. Indian Journal of Pediatrics, Volume 77—April, 2010.2. Nicole Tartaglia et al. 48,XXYY, 48,XXXY and 49,XXXXY syndromes: not just variants of Klinefelter syndrome. Foundation Acta Pædiatrica 2011 100, pp. 851–8602.