6th Year Pediatrics Practice Test

Klinefelter syndrome arises when a male has an extra X chromosome, leading to primary testicular failure. The testes become small and underdeveloped (dystrophic) due to seminiferous tubule damage, which lowers testosterone and impairs fertility, while the individual remains phenotypically male. This combination—male with small, atrophic testes—fits best. The other options point to different conditions: androgen insensitivity gives a female phenotype despite male chromosomes, XYY syndrome involves a different chromosomal pattern with often tall stature, and gonadal dysgenesis with ovotestis presents with ambiguous genitalia.