414 - An Investigation on the Effects of Hormonal Replacement Therapy upon the Behavioral Phenotype of Males with 49,XXXXY

49,XXXXY is a rare sex chromosome disorder, with an incidence of approximately 1:100,000. It has been associated with hypogonadism developmental dysfunction and externalizing problems. Hormonal replacement therapy (HRT) has been associated with improved neurodevelopmental outcomes in 47,XXY, early hormonal treatment (EHT) and hormonal booster therapy (HBT).

Objective:

This study investigates the effect of HRT on behavior in children with 49,XXXXY.

Design/Methods:

Parents of 63 children with 49,XXXXY (CA: 112 months) completed the Child Behavior Checklist (CBCL) and segregated based on HRT status: no-T (N = 22), EHT (N = 24), HBT (N = 6), and both EHT&HBT (N = 11). An ANOVA was completed to determine group differences.

Results:

No group differences were observed for demographic variables. The no-T presented heightened scores for externalizing problems compared to the EHT group (p = .0015) and for somatic complaints compared to the HBT group (p = .041). The EHT group showed decreased scores for somatic complaints and somatic problems in comparison to the HBT group (p = .0082, p = .018). The EHT&HBT group showed decreased scores for externalizing problems (p = .0019) compared to the EHT group, as well as for withdrawn/depressed (p = .0061), somatic complaints (p = .00066), internalizing (p = .0048), compared to the HBT group.

Conclusion(s):

This study explores the potential effects of HRT upon behavior in 49,XXXXY. Externalizing problems and somatic complaints/problems were most significantly affected by HRT. Our findings suggest that the combination of EHT&HBT has a possible dosage-dependent effect in mitigating behavioral difficulties such that this treatment group performs better than those treated with only EHT or HBT. This study adds to the paucity of literature exploring behavior in 49,XXXXY.