Table 1.

Phenotypic features of KS grouped according to the underlying pathogenetic mechanism

	Features due to supernumerary X chromosome	Features due to Testosterone deficiency	Features due to both supernumerary X chromosome and Testosterone deficiency
Onset Time	Before Puberty	At puberty or during adulthood	Before puberty with progressive worsening after puberty
Signs	Congenital malformations (cleft palate, hernia) [rare] Longer legs Small testes	Sparse body and facial hair Female pubic escutcheon Reduced muscle mass Bilateral gynecomastia Eunuchoid skeleton Impaired estradiol/testosterone ratio Longer legs? [T-deficiency during fetal life]??	Eunuchoid skeletal proportions Gynoid hips Tall stature Genital abnormalities at birth [rare] Elevated gonadotropins BMI in the range of overweight or obesity Metabolic abnormalities Reduced bone mineral density
Symptoms	Speech and language disabilities Azoospermia	Impaired sexual desire Impaired erectile function Weakness and loss of vigor Impaired well-being	Mood disturbances