Endocrine Abstracts

Congenital fibrous dysplasia is a rare disease with a broad spectrum of manifestations, including various endocrinopathies;precocious puberty, hyperthyroidism, excess growth hormone, hypophosphatemia mediated by FGF23.

We present the case of a 33 year old male, who presented in our endocrinology service with infertility and bone pain. He was diagnosed at the age of years old with congenital fibrous dyplasia and suffered multiple surgeries for bone decompression. Blood tests showed vitamin D insufficiency (16,01 ng/ml), very high levels of alkaline phosphatise (919 U/l), normal levels of calcium, phosphorus and parathormone. Bone mineral density was low at the femoral neck: BMD 1.385 g/cm², Tscore=−2.4, Zscore=−2.3.

His semen analysis showed a normal aspect, volume and viscosity, but with a low A mobility of spermatozoa and a low percentage of normal form spermatozoa.

His testosterone was within the normal range (3,44 ng/ml), with a TSH of 4,10 microUI/ml. We further performed a karyotype analysis, wich showed the presence of an extra X chromosome in 10% of the studied metaphases, with the diagnosis of mosaic Klinefelter:47XXY(10%)/46 XY (90%).

This is the first description of a case with congenital fibrous dysplasia which associates mosaic karyotype 46XY/47XXY. Although the link between the two conditions is not known, further investigations are necessary to establish a possible correlation between them. It remains to establish if karyotype analysis should be a routine investigation for those diagnosed with fibrous dysplasia.