Testosterone replacement in 49,XXXXY syndrome: andrological, metabolic and neurological aspects

We report the case of a 19-year-old boy, presenting several congenital malformations (facial dysmorphisms, cardiac and musculoskeletal abnormalities), mental retardation, recurrent respiratory infections during growth and delayed puberty. Although previously hospitalised in other medical centres, only psychological support had been recommended for this patient. In our department, genetic, biochemical/hormonal and ultrasound examinations were undertaken. The karyotype was 49,XXXXY, a rare aneuploidy with an incidence of 1/85 000–100 000, characterised by the presence of three extra X chromosomes in phenotypically male subjects. The hormonal/biochemical profile showed hypergonadotropic hypogonadism, insulin resistance and vitamin D deficiency. The patient was then treated with testosterone replacement therapy. After 12 months of treatment, we observed the normalisation of testosterone levels. There was also an increase in pubic hair growth, testicular volume and penis size, weight loss, homeostatic model assessment index reduction and the normalisation of vitamin D values. Moreover, the patient showed greater interaction with the social environment and context. LEARNING POINTS: In cases of plurimalformative syndrome, cognitive impairment, recurrent infections during growth and, primarily, delayed puberty, it is necessary to ascertain as soon as possible whether the patient is suffering from hypogonadism or metabolic disorders due to genetic causes. In our case, the diagnosis of hypogonadism, and then of 49,XXXXY syndrome, was unfortunately made only at the age of 19 years. The testosterone replacement treatment, even though delayed, induced positive effects on: i) development of the reproductive system, ii) regulation of the metabolic profile and iii) interaction with the social environment and context. However, earlier and timely hormonal replacement treatment could probably have improved the quality of life of this subject and his family.