[Osteoporosis in Turner syndrome with chromosomal mosaicism (45,XO/46,XY). A case report].

We report a rare case of Turner's syndrome (UTS) due to a gonosomal mosaic 45,X0/46,XY with the main clinical feature of several fractures in the course of osteoporosis. The bone mineral density (BMD) of the lumbar spine and the hip measured by DXA showed osteoporosis. The other clinical investigations including laboratory parameters presented beside an estrogen deficiency due to primary amenorrhea, a small thyroid with hypothyroidism, increased renal calciuria and increased markers of bone metabolism. Beside the supplementation of estrogen and thyroid hormone deficits, only a combination of different bone-associated drugs could normalize the bone mineral density and the bone turnover. During a two years' follow-up period no further fractures occurred. Furthermore, theories regarding the occurrence of osteoporosis and other complex pathologies in UTS are discussed with the conclusion that osteopenia in UTS is probably based on a multifactorial genesis. Due to these complex pathologies during adulthood, patients with UTS should get multidisciplinary care in order to reduce morbidity and preserve quality of life.