Effects of short-course androgen therapy on the neurodevelopmental profile of infants and children with 49,XXXXY syndrome.

AIM: The aim of this investigation was to ascertain whether an early course of androgen treatment (three injections testosterone enanthate, 25 mg) could have a positive impact on any domains of neurodevelopmental function in boys with 49,XXXXY. METHODS: A total of 22 boys with a karyotype of 49,XXXXY participated in a multidisciplinary assessment of neurocognition, speech and language, paediatric neurology and endocrinology evaluations. One group had received early androgen and another group did not receive any hormonal treatment prior to the evaluation. The mean age of treatment for Group 1 was 12 months with the mean age of first evaluation 74 months. The mean age of first evaluation for Group 2 was 87 months. Statistical analysis was completed to determine whether there was a positive treatment effect from androgen therapy. RESULTS: There was a significant positive treatment effect in speech and language domain, gestural communication and vocabulary development. No treatment effect was seen on nonverbal capacities. CONCLUSION: Our findings revealed improved function in several areas of development which had been severely delayed in boys with 49,XXXXY. Continued research is underway to expand our understanding of the relationship of androgen, brain function and behavioural outcome in boys with 49,XXXXY.

Clinical variability and novel neurodevelopmental findings in 49, XXXXY syndrome.

49, XXXXY is a rare chromosomal syndrome due to double nondisjunction of the replicating X chromosome. Considered a severe variant of XXY or Klinefelter syndrome, boys with this chromosome constitution are assumed to have severe mental retardation (MR) in addition to craniofacial, genital, endocrine, and heart abnormalities. Here, we present a multidisciplinary analysis including the clinical and neurobehavioral aspects of this condition in 20 boys with 49, XXXXY who share a common phenotype and neurobehavioral profile. The phenotypic presentation of the boys with 49, XXXXY shares some characteristics with 47, XXY, but there are also other unique and distinctive features. Previously unappreciated intact nonverbal skills are evident in conjunction with moderate to severe developmental dyspraxia. Variability in clinical and cognitive functioning may reflect skewed X inactivation, mosaicism, or other factors that warrant further investigation.