Maturational rate of Tokyo children with and without mental retardation.

The maturational rate of Tokyo children with and without mental retardation (ns = 175 and 249, respectively) was compared by means of longitudinal data on height covering the age period 6 to 15 years. Menarcheal age was obtained for 292 girls with and 262 girls without mental retardation. Results showed that the children with mental retardation had a lower growth spurt in height during puberty but did not differ in maturational rate defined by age at the pubertal height spurt or age at menarche.