Rates of 47, + 13 amd 46 translocation D/13 Patau syndrome in live births and comparison with rates in fetal deaths and at amniocentesis.

Trisomy 13 (Patau syndrome) is rare in newborns. Data on rates in 167,774 live births from 17 separate studies are reviewed, and the following pooled rates found for: (1) 47,trisomy 13, 8.3 X 10(-5) (1/12,000); and (2) 46, (D/13 Robertsonian translocations), 4.2 X 10(-5) (1/24,000)--mutants, 1.2 X 10(-5) (1/80,000) to 1.8 X 10(-5) (1/56,000); and familial cases, 2.4 X 10(-5) (1/42,000) to 3.0 X 10(-5) (1/33,000). The rate of trisomy 13 (47, + 13) in liveborns (ignoring possible biases in studies and heterogeneity in rates) is, with 95% confidence, between 4.6 X 10(-5) (1/21,700) and 14.0 X 10(-5) (1/7,000), with the most likely figure close to 8 X 10(-5) (1/12,000). Numbers are insufficient to construct a comparably narrow confidence interval for translocation cases. The rates of 47, + 13 may be estimated in (1) spontaneous abortuses, about 0.8%--1.0% (100-fold greater than in liveborns); (2) early neonatal deaths, about 0.4% (50-fold greater than in liveborns); and (3) amniocentesis, higher than in liveborns, at least for mothers 40 years and over.