7 doctors weighed in:
Is there a type of mosaic Down syndrome that doesn't require the mutation to come from either parent to have a downs child?
7 doctors weighed in

Dr. Robert Kwok
Pediatrics
4 doctors agree
In brief: Yes
A mosaic down syndrome child can come from a normal egg and normal sperm, produced by normal parents.
The fertilized egg would start out normal with 46 chromosomes. It can divide into 2 normal cells, which themselves divide again. If on one of the early divisions, one cell ends up with an extra #21 chromosome and survives to continue dividing, the child will be mosaic with some trisomy 21 cells.

In brief: Yes
A mosaic down syndrome child can come from a normal egg and normal sperm, produced by normal parents.
The fertilized egg would start out normal with 46 chromosomes. It can divide into 2 normal cells, which themselves divide again. If on one of the early divisions, one cell ends up with an extra #21 chromosome and survives to continue dividing, the child will be mosaic with some trisomy 21 cells.
Dr. Robert Kwok
Dr. Robert Kwok
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Dr. Jonathan Nehrer
Pediatrics - Psychiatry
1 doctor agrees
In brief: See below
You may be talking about a spontaneous mutation.
Neither parent has downs. But a mutation in the egg cell or sperm cell produces the child with down's.

In brief: See below
You may be talking about a spontaneous mutation.
Neither parent has downs. But a mutation in the egg cell or sperm cell produces the child with down's.
Dr. Jonathan Nehrer
Dr. Jonathan Nehrer
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