title: Comparison of adolescents with Klinefelter syndrome according to the circumstances of diagnosis: amniocentesis versus clinical signs.
abstract: OBJECTIVE
  We compared the phenotype of adolescents with Klinefelter syndrome diagnosed by amniocentesis or postnatally to the general population with a view to evidence-based genetic counselling.
  
  
  METHODS
  The charts of 28 patients seen between ages 12 and 18 years were reviewed. Physical and neurodevelopmental data were compared between patients diagnosed by chance (amniocentesis, group A, n = 11) or on the basis of symptoms (group B, n = 17) and the general population. Our hypothesis was that group A would have a more heterogeneous and less severe phenotype than group B.
  
  
  RESULTS
  All patients had spontaneous puberty. The 2 patient groups were similar in physical development. Mean testosteronemia became lower than the normal mean from age 14 years. Compared to the general population, the prevalence of gynecomastia and school delay in group A was not significantly different (gynecomastia 33 vs. 40%, p = 0.70; school delay 40 vs. 20%, p = 0.25). In contrast, gynecomastia (77%) and school delay (56%) were significantly more frequent in group B than in the general population (p = 0.01 for both).
  
  
  CONCLUSIONS
  Although they are based on a small number of patients, our data provide the groundwork for cautious optimism in prenatal counselling for Klinefelter syndrome.
authors.affiliation: CHU Sainte-Justine, Endocrinology Service, Montreal, Que., Canada.
authors.forename: Céline M
authors.initials: CM
authors.lastname: Girardin
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Lemyre
authors.forename: Nathalie
authors.initials: N
authors.lastname: Alos
authors.forename: Cheri
authors.initials: C
authors.lastname: Deal
authors.forename: Céline
authors.initials: C
authors.lastname: Huot
authors.forename: Guy
authors.initials: G
authors.lastname: Van Vliet
mesh_terms: D000293:Adolescent; D002648:Child; D005817:Genetic Counseling; D006177:Gynecomastia / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology; D006801:Humans; D007713:Klinefelter Syndrome / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology*; D008297:Male; D011627:Puberty; D012042:Registries; D012189:Retrospective Studies; D013739:Testosterone / Q000097:blood
chemical_list: D013739:Testosterone