ComplicationsBy Mayo Clinic staff
Complications of Klinefelter syndrome can include:
- Increased risk of certain birth defects, including curved fifth fingers and cleft palate
- Delayed puberty
- Noticeable physical features, such as sparse facial and body hair, unusually long legs and arms, lack of muscular development, and enlarged breast tissue
- Learning disabilities, attention problems or social development issues
- Weak bones (osteoporosis)
- Increased risk of varicose veins and other problems with blood vessels
- Increased risk of breast cancer and cancers of the blood, bone marrow or lymph nodes
- Increased risk of lung diseases, such as chronic bronchitis
- Increased risk of autoimmune disorders, such as type 1 diabetes and lupus
- Increased belly fat, which can lead to other health problems
- Problems with sexual function
A number of complications caused by Klinefelter syndrome are related to low testosterone (hypogonadism). Testosterone replacement therapy reduces the risk of certain health problems, especially when therapy is started at the beginning of puberty.
- Bock R. Understanding Klinefelter syndrome: A guide for XXY males and their families. National Institute of Child Health & Human Development. http://www.nichd.nih.gov/publications/pubs/klinefelter.cfm. Accessed Aug. 30, 2010.
- Zeger M, et al. Effect of ascertainment and genetic features on the phenotype of Klinefelter syndrome. Journal of Pediatrics. 2008;152:716.
- Klinefelter syndrome. Genetics Home Reference. http://www.ghr.nlm.nih.gov/condition/klinefelter-syndrome. Accessed Aug. 30, 2010.
- Klinefelter syndrome. National Institute of Child Health & Human Development. http://www.nichd.nih.gov/health/topics/klinefelter_syndrome.cfm. Accessed Aug. 30, 2010.
- Ramasamy R, et al. Successful fertility treatment for Klinefelter's syndrome. Journal of Urology. 2009;182:1108.
- Radicioni AF, et al. Strategies and advantages of early diagnosis in Klinefelter's syndrome. Molecular Human Reproduction. 2010;16:434.
- Bruining H, et al. Psychiatric characteristics in a self-selected sample of boys with Klinefelter syndrome. Pediatrics. 2009;123:e865.
- Sex chromosome anomalies. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merck.com/mmpe/print/sec19/ch294/ch294g.html. Accessed Sept. 23, 2010.
- Wattendorf DJ, et al. Klinefelter syndrome. American Family Physician. 2005;72:2259.
- Klinefelter syndrome. The Hormone Foundation. http://www.hormone.org/upload/Klinefelter-Bilingual-WEB.pdf. Accessed Aug. 30, 2010.
- Learning about Klinefelter syndrome. National Human Genome Research Institute. http://www.genome.gov/pfv.cfm?pageID=19519068. Accessed Aug. 30, 2010.
- Snyder PJ. Causes of primary hypogonadism in males. http://www.uptodate.com/home/index.html. Accessed Aug. 30, 2010.