Effects of consanguineous marriages on morbidity and precocious mortality: genetic counseling.
The excess risks of morbidity and precocious mortality for the offspring of incestuous matings and of matings of uncles-nieces and aunts-nephews, first cousins, first cousins once removed, and second cousins have been estimated as 32%, 18%, 9%, 5%, and 2.5%, respectively. These estimates are based on the theory of Morton et al [1956], assuming a damage (genetic and nongenetic) of 20% for the offspring of nonconsanguineous couples and two "deleterious" equivalents per gamete. Other possibilities (a damage of 40%; 2.5 deleterious equivalents per gamete), a partition of the total risk into prenatal and postnatal events, and some aspects of the inbreeding theory are also presented. Comments intended for persons interested in counseling are provided.
D000293:Adolescent; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D000013:Congenital Abnormalities / Q000235:genetics; D003241:Consanguinity; D005260:Female; D005313:Fetal Death / Q000235:genetics; D005787:Gene Frequency; D005817:Genetic Counseling; D006801:Humans; D007179:Incest; D007223:Infant; D007226:Infant Mortality; D007231:Infant, Newborn; D008607:Intellectual Disability / Q000235:genetics; D008297:Male; D009017:Morbidity; D009026:Mortality; D011247:Pregnancy; D012306:Risk