A longitudinal perspective of hormone replacement therapies (HRTs) on neuromotor capabilities in males with 47,XXY (Klinefelter syndrome).

Purpose: The purpose of this study was to delineate the effects of variable hormone replacement therapies on neuromotor function in a large cohort of males with 47,XXY from birth to adulthood.

Methods: A total of 270 participants aged 16 days to 17 years 11 months prenatally diagnosed with 47,XXY were assessed by their pediatric endocrinologist and were administered hormone replacement therapies accordingly. Infants and school-aged children with 47,XXY were administered neuromotor assessments during routine neurodevelopmental evaluations.

The effect of early hormonal treatment (EHT) on expressive and receptive language capabilities in boys with 47,XXY (Klinefelter syndrome) during infancy and early childhood.

Purpose: 47,XXY is associated with variable neurodevelopmental outcomes including deficits in expressive and receptive language development. Early hormonal treatment (EHT) has been associated with mitigating some deficiencies in boys with 47,XXY. This study investigates these language capabilities of 47,XXY boys in the first five years of life and the associated effects of EHT on these capabilities.