Hormonal replacement therapy and its potential influence on working memory and competency/adaptive functioning in 47,XXY (Klinefelter syndrome).

This cross-sectional, retrospective analysis investigated the possible effect of hormonal replacement therapy (HRT) on working memory (WM) and competency/adaptive functioning (CAF) in boys with 47,XXY; the effect of timing of 47,XXY diagnosis on these variables; and the relationship between WM and CAF, if any. A total of 111 boys with 47,XXY, ranging from 6 to 16 years of age (M = 9 years 4 months; SD = 2 years 1 month), were evaluated using the Wechsler Intelligence Scale for Children, and Child Behavior Checklist. Participants were grouped by HRT status and timing of diagnosis. Analysis of variance testing performed on the prenatally diagnosed boys revealed a statistically significant difference in WM for the HRT groups (F[3,84] = 7.467, p = .000174), where WM of the no-HRT group (M = 92.37, SD = 17.83) was lower than that of the early hormonal therapy group (M = 106.39, SD = 12.01; p = .0092). Additionally, there was a positive correlation between low WM capabilities and poor school performance (r = .5106, p = .0027) in the prenatally diagnosed, untreated boys. Our results highlight the potentially positive effects of HRT on WM and CAF in boys with 47,XXY. Further research is required to better determine the underlying relationship among the biological mechanisms of HRT, WM, and CAF outcomes, and timing of diagnosis in boys with 47,XXY.