TY - JOUR T1 - Clinical variability and novel neurodevelopmental findings in 49, XXXXY syndrome. AU - Gropman,Andrea L, AU - Rogol,Alan, AU - Fennoy,Ilene, AU - Sadeghin,Teresa, AU - Sinn,Stephanie, AU - Jameson,Robert, AU - Mitchell,Francine, AU - Clabaugh,Jaye, AU - Lutz-Armstrong,Margaret, AU - Samango-Sprouse,Carole A, PY - 2010/5/27/entrez PY - 2010/5/27/pubmed PY - 2010/8/31/medline SP - 1523 EP - 30 JF - American journal of medical genetics. Part A JO - Am J Med Genet A VL - 152A IS - 6 N2 - 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. SN - 1552-4833 UR - https://www.unboundmedicine.com/medline/citation/20503329/Clinical_variability_and_novel_neurodevelopmental_findings_in_49_XXXXY_syndrome_ L2 - https://doi.org/10.1002/ajmg.a.33307 DB - PRIME DP - Unbound Medicine ER -