BIRTH PREVALENCE, MUTATION-RATE, SEX-RATIO, PARENTS AGE, AND ETHNICITY IN APERT-SYNDROME

Apert syndrome was studied to determine birth prevalence, mutation rat e, sex ratio, parents' age, and ethnicity among 2,493,331 Live births registered in the California Birth Defects Monitoring Program (CBDMP) from 1983 through 1993; 31 affected infants were identified, The sampl e was completed with an additional 22 cases from the Center for Cranio facial Anomalies (CCA), University of California, San Francisco, for a total of 53 affected children, Birth prevalence, calculated from the CBDMP subsample, was 12.4 cases per million live births (confidence in terval [CI] 8.6, 17.9), The calculated mutation rate was 6.2 x 10(-6) per gene per generation, Asians had the highest prevalence (22.3 per m illion live births; CI 7.1, 61.3) and Hispanics the lowest (7.6 per mi llion, CI 3.3-16.14). In the large population-based CBDMP subsample, t here was an almost equal number of affected males and females, (sex ra tio 0.94) but in the clinical CCA. subsample, there were more affected females (sex ratio 0.79), For all cases, the mean age of mothers was 28.9 +/- 6.0 years, and of fathers was 34.1 +/- 6.2 years, Almost half of fathers were older than 35 years when the child was born; for more than 20% of cases, both parents were older than 35 gears, These findi ngs may support the view that point mutations appear to be more common ly associated with paternal than with maternal alleles. Representing t he largest systematically ascertained population-based study of apert syndrome to date, they provide a reliable basis for genetic counseling and decision-making, and for focused research to define the cause of this syndrome. (C) 1997 Wiley-Liss, Inc.