Endocrine Abstracts

Introduction: Klinefelter syndrome is the most prevalent male chromosomal disorder, characterized by the presence of additional X chromosomes. Most males with Klinefelter syndrome have 47, XXY and normal intelligence. Intellectual disability occurs in males with Klinefelter syndrome variants, who have a higher number of X chromosomes. Here we report a rare case of a 49, XXXXY syndrome revealed by intellectual deficit and pubertal delay.

Observation: An 18-year-old male patient was presented in our department for pubertal delay associated with intellectual deficit. He showed dry mouth, polydipsia, and polyuria. On examination, he had short stature: height = 166 cm, weight = 67 Kg, BMI = 24.3 Kg/m², hypertelorism, gynecomastia, atrophic testes and micropenis. Biological examination showed diabetes mellitus and hypertriglyceridemia. Hormonal analysis confirmed a hypergonadotropic hypogonadism (Testosterone = 20 ng/dl, LH=29 IU/l, FSH= 55 IU/l). Thyroid function was normal and his IGF-1 level was low (170 [224-255 ng/ml]). Imaging examination showed a bone age of 16 years and cardiac anomalies: mitral and aortic insufficiencies. Genetic analysis exhibited a 49, XXXXY karyotype and the patient underwent testosterone therapy.

Conclusion: 49, XXXXY syndrome is a rare variant of Klinefelter syndrome with an incidence of 1/85,000 male births. Its diagnosis is usually made postnatally because of growth deficiency and dysmorphism which wasn’t the case for our patient. Malformations and intellectual deficit are other characteristics of this syndrome that requires performing a karyotype.