Early Menarche in Japanese Down Syndrome

To the Editor. We obtained information on 95 female patients (age 9–18 years) with Down syndrome in Japan. The period of their birth was between 1976 and 1984 (median 1980). The mean menarcheal age of 60 menstruating subjects was 12.1 ± 1.2 (SD) (Table 1). It was earlier than that of recent Japanese women (12.5 ± 1.0, N = 1,161 birth year 1974–19791) ( P < .05). View this table: Table 1. Early Menarche in Down …