title: Klinefelter syndrome: expanding the phenotype and identifying new research directions.
abstract: OBJECTIVE
  The purpose of this study is to summarize new data on etiology and clinical features of Klinefelter syndrome in order to derive research priorities.
  
  
  METHODS
  This study was conducted using critical reviews of selective topics, emphasizing less well-recognized clinical findings.
  
  
  CONCLUSIONS
  The phenotype of the prototypic 47,XXY case is well recognized: seminiferous tubule dysgenesis and androgen deficiency. Less well appreciated is the varied expressivity of 47,XXY Klinefelter syndrome, in particular neurological/cognitive perturbations like language and behavioral problems. Effective therapies are available. Reproductive technologies allow 47,XXY men to sire offspring through intracytoplasmic sperm injection (ICSI); however, genetic counseling is complex and success is low. Behavioral and expressive language difficulties are amenable to treatment by androgen therapy and psychological help. Early treatment may be imperative for optimal outcome.
authors: Baylor College of Medicine, Houston, Texas 77030, USA.
authors: Joe Leigh
authors: JL
authors: Simpson
authors: Felix
authors: F
authors: de la Cruz
authors: Ronald S
authors: RS
authors: Swerdloff
authors: Carole
authors: C
authors: Samango-Sprouse
authors: Niels E
authors: NE
authors: Skakkebaek
authors: John M
authors: JM
authors: Graham
authors: Terry
authors: T
authors: Hassold
authors: Melissa
authors: M
authors: Aylstock
authors: Heino F L
authors: HF
authors: Meyer-Bahlburg
authors: Huntington F
authors: HF
authors: Willard
authors: Judith G
authors: JG
authors: Hall
authors: Wael
authors: W
authors: Salameh
authors: Kyle
authors: K
authors: Boone
authors: Catherine
authors: C
authors: Staessen
authors: Dan
authors: D
authors: Geschwind
authors: Jay
authors: J
authors: Giedd
authors: Adrian S
authors: AS
authors: Dobs
authors: Alan
authors: A
authors: Rogol
authors: Bonnie
authors: B
authors: Brinton
authors: C Alvin
authors: CA
authors: Paulsen
mesh_terms: D035843:Biomedical Research; D005817:Genetic Counseling; D006801:Humans; D007361:Intelligence Tests; D007713:Klinefelter Syndrome / Q000235:genetics* / Q000523:psychology; D007804:Language Development; D008297:Male