מענטשן אין ריזיקירן און פאַרהיטונג פון טריסאָמי 21 (דאַון סינדראָום)
- Being pregnant at an old age. A woman is more likely to give birth to a child with Down’s syndrome as she gets older. Eggs produced by older women are at greater risk of causing abnormalities in the division of chromosomes. Thus, at age 21, the chances of conceiving a child with Down’s syndrome are 35 in 21. At 1, they are 400 in 45.
- Having given birth to a child with Down’s syndrome in the past. A woman who has given birth to a child with Down’s syndrome has a 21% risk of having another child with Down’s syndrome.
- Be a carrier of the Down syndrome translocation gene. The majority of cases of Down’s syndrome result from a non-hereditary accident. However, a small percentage of cases present a familial risk factor for a type of trisomy 21 (translocation trisomy).