Abstract

The 48,XXYY syndrome represents a chromosomal aneuploidy which consists in the presence of an extra X and Y chromosome in males. It has an incidence of 1/18 000 to 1/50000 male births. For a long time 48,XXYY syndrome was considered as a variant of Klinefelter syndrome, but nowadays it is treated as a distinct disorder.

This is the case of a healthy newborn delivered at 39 weeks of gestation in which very minor, non-specific facial dysmorphism was observed: hypertelorism, enlarged bitemporal diameter, flat occiput, downwardly and oblique displaced ears, short lingual frenulum and another dysmorphic characteristic:clinodactyly of the fifth digit.The transfontanelar sonography identified two choroid plexus cysts and no other modifications. Abdominal and cardiac sonography showed no abnormalities. Due to these characteristics, a genetic consult was made and the karyotype revealed the aneuploidy.

This rare gonosomic aneuploidy is exceptionally discovered during childhood because there are no specific modifications. No other case discovered immediately after birth was reported in the literature. Most of cases are diagnosed after puberty because its phenotype similar to the Klinefelter’s syndrome or due to variable developmental, cognitive, behavioural and physical abnormalities. It is important to differentiate it from Klinefelter’s syndrome because there are a variety of behaviours, learning disabilities and emotional problems that are unique to patients with XXYY syndrome that may be better addressed with more targeted therapies.

There are specific brain changes in patients with 48, XXYY syndrome: grey and white matter modifications, larger lateral ventricular volumes, colpocephaly and abnormalities of the corpus callosum. None of these was discovered in our case.

Patients have a normal life expectancy but need regular medical visits, for respiratory and endocrine problems and their predisposition to infections. Patients should also be followed-up by a psychiatrist starting from childhood.

This is considered a rare disorder because approximately 100 cases with 48,XXYY have been reported to date. As far as we know, this is the first reported case in Romania.