1. Klinefelter’s Syndrome Noorunnehar Qureshi

2. A Brief Introduction XXY Nondisjunction resulting in a trisomy of the sex chromosomes Usually because of a random error during formation of egg or sperm Can also be due to replication error after conception Does not always prevent in obvious way Occurs in ~1 in 650 males

3. Manifestation and Treatment The syndrome usually presents with – Tall stature – Hypogonadism – Fertility problems – Cognitive/language deficits of varying severity – Gynecomastia – Female distribution of fat and body hair – Decreased brain volume – Infertility – Unsuppressed FSH and LH Treatment – Androgen therapy

4. Citations Boada, R., Janusz, J., Hutaff-Lee, C., & Tartaglia, N. (2009). The Cognitive Phenotype in Klinefelter Syndrome: A Review of the Literature Including Genetic and Hormonal Factors. Developmental Disabilities Research Reviews,15(4), 284–294. http://doi.org/10.1002/ddrr.83 Giltay, J., & Maiburg, M. (2010). Klinefelter syndrome: Clinical and molecular aspects. Expert Review of Molecular Diagnostics, 15(4), 765-776. doi:10.1586/erm.10.63. Wattendorf, D., & Nye, N. (2005). The Klinefelter Syndrome. American Family Physician, 72(11), 2259-62. Retrieved September 7, 2015, from http://www.ncbi.nlm.nih.gov/pubmed/16342850?dopt=Ab stract