A mother has a first child of "Trisomy-21" (Down's syndrome). What is the percentage of occurrence of reccurence in 2nd child?

(D) 1% > Women 35 years of age or less who have a child with trisomy have a 1 % risk of having another child with down syndrome, which is significantly greater than the general population. The risk is little increased if the mother at risk is 35 years or older. For translocations inherited from the mother, the risk of recurrence is about 10 percent, whereas it is about 4-5 percent when father is the carrier.> Risk of Recurrence Women 35 years of age or less who have a child with trisomy have a 1 % risk of having another child with down syndrome, which is significantly greater than the general population. The risk is little increased if the mother at risk is 35 years or older. For translocations inherited from the mother, the risk of recurrence is about 10 percent, whereas it is about 4-5 percent when father is the carrier.