clinical features
Last reviewed 10/2020
Testosterone deficiency and unsuppressed follicle-stimulating and luteinizing hormones activity (directly or indirectly) is responsible for the most common phenotypic features seen in KS (1).
Characteristic clinical findings of a male with KS are as follows:
- infertility (azoospermia or oligospermia)
- in mosaic cases, reports of pregnancy without assisted medical technology has been reported
- small, firm testes - in postpubertal patients the testicular volume is typically less than 10 ml
- gynecomastia - incidence of gynecomastia in KS may vary between 56% to 88%
- tall, slender body structure with long legs and shorter torso
- features of persistent androgen deficiency -
- loss of libido
- reduced beard growth and secondary body hair
- decreased muscle bulk and tone
- decreased bone mineral density
- susceptibility for thromboembolism
- an increased risk of mortality from diabetic and cardiovascular complications
- motor delay or dysfunction
- speech and language difficulties
- attention deficits
- dyslexia or reading dysfunction
- psychosocial or behavioral problems (2,3)
Reference:
- (1) Wattendorf DJ, Muenke M. Klinefelter syndrome. Am Fam Physician. 2005;72(11):2259-62.
- (2) Visootsak J, Graham JM Jr. Klinefelter syndrome and other sex chromosomal aneuploidies. Orphanet J Rare Dis. 2006;1:42.
- (3) Bojesen A, Gravholt CH. Klinefelter syndrome in clinical practice. Nat Clin Pract Urol. 2007;4(4):192-204.
mental retardation (term that has been replaced by intellectual developmental disorder)
most prominent signs according to age of individual with Klinefelter's syndrome