Not very likely, I know of no family that has 2, and I have worked in this field for 38 years,
Just because you know of no familly that has 2, doesn't make you an expert. My son and d in law have only two biological children and both of them have DS. They have had no other pregnancies. The boys are two years apart. Both are considered mosaic, one is only 6% so, the other more likely 75% normal cells. The genetisists can find no reason, but in my mind, there must be something linking the two. The doctors feel it was a case of "lightning striking twice." I don't really buy that, although there is no major history of DS in our two families. Her family might have one aunt with DS, but that is all that we have found. They have two different types of DS, as well. One has translocation DS, the other the more standard extra chromosome (trisomy 21).
Nobody in my family or my partners family has Down's syndrome yet my son does so it's nothing genetical.
I am the mother of a 17 year old who has Down syndrome. I had her when I was 24 years old. She has trisomy 21 - the "fluke of nature" Down syndrome (not mosaic which is hereditary and rare). I had my second child two years later and she was born healthy with no genetic abnormalities or health problems. She is a typical 15 year old.
When I was 38 I was pregnant with my 3rd child. He also had Down syndrome - trisomy 21, the "fluke". I had multiple complication, severe phenomia that I was hospitalized for, another infection on top of that that could not easily be treated while pregnant. On top of that my baby had severe heart abnormalities and was not growing. I had the impossible decision to make of keeping the pregnancy and trying to survive with the very real chance of miscarriage or terminating the pregnancy for medical reasons.
People can judge others for the desisions they make, but you can not know until you are walking in someone else's shoes and the complexities of a situation how that feels and the weight of that desision.
I tried to find others who had two children with Down syndrome to gain perspective and insight furring this awful time. I found two families. One who had twins with DS and one who had a son and daughter as well as a few other healthy children. It seems to be rare to find this situation but it happens and I wouldn't be surprised if it doesn't happen more often than not but due to conplications or person family choices the pregancies are lost.
It is a difficult feeling to know that 2 out of 3 of your children have Down syndrome. You question yourself even though you can rationalize this is just the way fate had it. Also, we who have been in this situation, might naturally feel and find it hard to understand how people can have, healthy child after healthy child, even into thier 40s but we seem to not be able to have this same experience. We are only human and it hurts.
I wish anyone facing this the best of luck, a strong support system, and optimisim to carry them through.
I have 2 cousins, brother and sister, born about 2 years apart, with Down Syndrome. Their other 2 siblings were normal. As translocation was suspected, all of my cousins and I underwent genetic counseling when we started our families.