Contribution of chromosome abnormalities to human morbidity and mortality.

Estimates of the association of chromosome aberrations with various adverse health outcomes are as follows: embryonic and fetal death (5-28 weeks), 33%; stillbirths, 5-10%; infant and early childhood death, 5-7%; retardation (IQ less than 50), 20-35%; (IQ 50-69), 5-15%; criminality an d retardation or psychiatric disturbance in males, 3%; other criminality, 0.3-0.8%; birth defects, 2.5-8%; heart defects, 10%; subfertility or infertility, 2-8%; multiple miscarriages, less than 1 to 13%; male pseudohermaphroditism, less than 25%; and primary amenorrhea, 25%. Variations in rates reflect statistical fluctuations and variations in the selection of populations for study. The estimates are based on currently used techniques; cryptic structural rearrangements may also contribute significantly to these outcomes.