Abstract
48,XXYY syndrome is a rare sex chromosome aneuploidy (SCA) condition affecting 1 in 18,000-40,000 male births. Clinical features include tall stature, hypergonadotropic hypogonadism (testosterone deficiency), infertility, developmental delays, learning disabilities, and intellectual impairment. Co-occurring behavior and mental health challenges are common in this population, with high rates of attention-deficit hyperactivity disorder (ADHD), anxiety, depression, sleep disorders, irritability, and aggressive behaviors. We evaluated psychotropic medication use by parent report and retrospective chart review. Treatment success was defined as a positive response per parent report, positive clinician rating, or a treatment duration of at least 6 months. Nearly three-quarters of participants (71/101) with a median age of 15.9 (range 4.5-38 years) had received psychotropic medications. The most common medication classes used were stimulant ADHD medications (78.9% of those with medication use), with a median age of first use of 9 years ([IQR] 7, 11 years), followed by anti-anxiety/antidepressant medications (60.6%), with a median age of first use of 10 years ([IQR] 8, 14 years). Treatment success rates ranged from 43.9% to 84.2% for individual medication trials. Subsequent trials of medications within the same class improved success rates per person in all medication classes except for sleep and mood stabilizer medications. Treatment failure due to side effects was greatest among neuroleptics/atypical antipsychotics, whereas treatment failure due to inefficacy was greatest among anti-anxiety/antidepressants and mood stabilizers. The findings of this study suggest that psychotropic medications targeting behavior and mental health are common and overall helpful for individuals with 48,XXYY.