Congenital anomalies in the Hutterite population: a preliminary survey and hypothesis.

The Alberta Provincial Congenital Anomaly (CA) Surveillance reporting forms were scanned for infants whose surnames and addresses identified them as belonging to the Hutterite Brethren. Death registrations (of infants up to 1 year) and stillbirth registrations were similarly scanned. While the overall percentage of total malformations (5%) and major malformations (2%) was no different from that of the total population of Alberta, closer examination of the actual entities showed a large number of monogenic disorders among the Hutterites. The frequency of multifactorial congenital anomalies was approximately 1%. The inbreeding coefficients, using a genealogic data base, were computed for each "case baby" and two Hutterite "control babies," the latter being births preceding and succeeding the case baby. There was no statistical difference in the distribution of inbreeding coefficients between the case and control groups. While the data are based on small numbers and therefore are preliminary, they suggest that the Hutterite lifestyle, of good nutrition (using largely home prepared foods), absence of tobacco and minimal alcohol consumption, may be one factor responsible for fewer multifactorial CAs whose occurrence is environmentally susceptible to such influences. Studies of populations with a low incidence of disorders are just as important as those with a high incidence.