A tall, thin 14-year-old adolescent male has no signs of puberty. He was delayed in his speech development and always has done less well in school than his siblings. He is shy, and teachers report his activity is immature. Physical examination reveals breast development, and long limbs with a decreased upper segmentlower segment ratio. He has small testes and phallus.

A 15-year-old adolescent female with primary amenorrhea is noted to be well below the fifth percentile for height. She has hypertension, a low posterior hairline, prominent and low-set ears, and excessive nuchal skin.