First baseline data of the Klinefelter ItaliaN Group (KING) cohort: Clinical features of adult with Klinefelter syndrome in Italy

Background Klinefelter syndrome (KS) is frustratingly under-diagnosed. KS have a broad spectrum of clinical features, making it difcult to identify. Objective We describe KS clinical presentation in a large Italian cohort. Design This is the frst observational cohort study within a national network, the Klinefelter ItaliaN Group (KING). Primary outcomes were to describe the basic clinical features and the actual phenotype of KS in Italy. Secondary outcomes were to determine age at diagnosis and geographical distribution. Methods We performed a basic phenotyping and evaluation of the hormonal values of 609 adult KS patients. Results Mean age at diagnosis was 37.4±13.4 years. The overall mean testicular size was 3 ml, and 2.5 ml in both testes in untreated KS group. BMI was 26.6±5.8 kg/m2 , and 25.5% of KS had metabolic syndrome (MetS). LH and FSH were increased, and mean total testosterone were 350±9.1 ng/dl. A descriptive analysis showed that 329 KS patients were evaluated in Northern Italy, 76 in Central and 204 in Southern Italy. Analysis of variance demonstrated signifcant statistical diferences (p<0001) between the age at diagnosis of the three geographical groups. Compared with the expected number among male patients matched for age in Italy, only 16% of KS patients received a diagnosis. Conclusions These data are the results of the only national database available that collects the clinical and hormonal data of the KS patients, currently referred at the KING centers. In Italy the typical KS patient is overweight, with small testes, and elevated LH and FSH. Only 25.5% of them are diagnosed with MetS. Early detection and timely treatment are mandatory.