Fig. 1

Absolute prevalence of Turner syndrome, Klinefelter syndrome, Triple X syndrome and Double Y syndrome in the Danish population. The observed number of a Turner syndrome (TS) and Triple X syndrome and b Klinefelter syndrome (KS) and Double Y syndrome (Double Y) being alive during 1970–2014 are illustrated by solid and dotted lines. Deceased or emigrated individuals were subtracted. Dashed lines indicate the expected number assuming a true prevalence of 1) 50 TS per 100,000 at birth; 2) 84 Triple X per 100,000 at birth; 3) 152 KS per 100,000 at birth; and 4) 98 Double Y per 100,000 at birth as well as a similar mortality as in the general population