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

In infants with 47,XXY, the early hormonal treatment (EHT) group performed significantly better than the untreated group on fine motor and motor composite domains.

• Study included 270 participants aged 16 days to 17 years 11 months prenatally diagnosed with 47,XXY.
• Two-tailed t tests, 1-way analysis of variance, and post hoc analysis were used to determine significant group differences.
• Participants were segregated on the basis of treatment status for statistical analysis.
• Neuromotor assessments were administered during routine neurodevelopmental evaluations.

In school-aged children with 47,XXY, EHT (or any combination thereof) was associated with significantly improved scores on fine motor control, coordination, agility, and strength domains compared with those who did not receive early treatment.

• The comparison was between males treated with EHT or any combination thereof versus those who did not receive early treatment.
• Domains showing improvement included fine motor control, coordination, agility, and strength.
• Post hoc analyses were used to determine specific group differences.
• School-aged children were assessed by their pediatric endocrinologist and administered hormone replacement therapies accordingly.

The highest treated combination group was associated with the highest neuromotor function among males with 47,XXY.

• Multiple hormone replacement therapy combinations were examined across the cohort.
• The EHT group also often performed better than other treatment groups, not just the untreated group.
• This pattern was observed from infancy through school age.
• The authors concluded that EHT may be essential in promoting long-term optimal neuromotor outcome in males with an additional X chromosome.

The study used a longitudinal design to assess neuromotor capabilities across a wide age range in a large cohort of prenatally diagnosed males with 47,XXY.

• Total cohort consisted of 270 participants.
• Age range spanned from 16 days to 17 years 11 months.
• All participants were prenatally diagnosed with 47,XXY.
• Participants received neuromotor assessments during routine neurodevelopmental evaluations and were managed by a pediatric endocrinologist.

Early hormonal treatment may be essential in promoting long-term optimal neuromotor outcome in males with 47,XXY (Klinefelter syndrome).

• This conclusion was supported by findings across both infant and school-aged groups.
• The EHT group frequently outperformed other treatment groups as well as the untreated group.
• Neuromotor domains assessed included fine motor, motor composite, coordination, agility, and strength.
• The authors suggest the additional X chromosome's neuromotor impact may be mitigated by early hormonal intervention.