Turner syndrome: the Leuven experience (1965-1989) in 478 patients. I. Patient's age at the time of diagnosis in relation to chromosomal findings.

Within the past 25 years 478 patients with Turner syndrome have been diagnosed in the Leuven Centre for Human Genetics. After exclusion of 36 lost pregnancies, mostly first trimester spontaneous abortions, almost 20 per cent of the remaining 442 Turner syndrome patients have been early detected, i.e. before the age of two years. Moreover, a high prevalence of classic 45,X karyotype over other karyotypes was observed in this age group. The high mortality of prenatally diagnosed Turner syndrome fetuses is discussed here in view of the most common associated congenital malformations.