Klinefelter SyndromeJoseph Tang ET 11B AP Biology
nondisjunction in meiosis
extra X chromosome(s) gamete has >1 sex chromosome zygote has >2 sex chromosomes
XXY/XXXY/XXYY etc.
Causes
breasts o.o lack of body hair lack of testosterone lower physical ability
Symptoms
aspermatogenesis karyotype: blood
sample WBCs separated chromosomal abnormalities (e.g. X chromosome)
Diagnosis
emotional problems/social pressure
decreased life expectancy (not definitive)
disease (osteoporosis, breast cancer etc.)
Prognosis
irreversible (genetic) psychosocial support cosmetic surgery to
remove breasts
Treatment
Harry Klinefelter (1942): reports about men with large breasts and little body hair
1950s: research on more symptoms
1970s: studies on newborns confirm disease
History