I’m not one to post something very data filled and boring, but here goes:
Babies born with Down syndrome have an extra chromosome. Chromosomes are made up of DNA, the building blocks of life. Chromosomes are almost like strings, and they contain every piece of information about our genetic makeup.
Everybody has 23 pairs of chromosomes, or 46 chromosomes in total. Each pair is inherited from your parents – one from your mother and one from your father. Two of your chromosomes are responsible for determining what sex you are – for males the sex chromosome is XY and for females it is XX. (that last part I copied and pasted).
The medical term for Down syndrome (not Downs syndrome or even Downs. People get mad at you for that. Not me. But others) is trisomy 21. A trisomy occurs when a baby has 3 copies of a chromosome instead of just two. The 21 indicates where the extra chromosome is located. There are a couple of types of trisomies, and many kinds of chromosomal abnormalities. It’s thought that up to 70% of all first trimester miscarriages are because of chromosomal abnormalities. That part is VERY interesting to me as I have had 2 miscarriages (one was thought to be right about the 13th week…so still first trimester). Abby’s twin very likely had a chromosomal abnormality. It makes me wonder about autism. It makes me wonder if Lance and I have chromosomal abnormalities ourselves (I could have triple X, Lance could have XXY- most people with such abnormalities never know that they do..but I digress). I’d like to eventually get the whole family tested. We’re being enrolled right now to study Casey’s chromosomes along with Lance’s and mine, but I don’t know when that will take place.
I had always thought that Down syndrome was a result of a problem in the egg. This is not always true. Most of the time, the occurrence of Down syndrome is due to a random event that occurred during formation of the reproductive cells, the ovum or the sperm. In 88% of cases, the extra copy of chromosome 21 is derived from the mother. In 8% of the cases, the father provided the extra copy of chromosome 21. In the remaining 2% of the cases, Down syndrome is due to mitotic errors, an error in cell division which occurs after fertilization when the sperm and ovum are joined.
I also thought that most children with Down syndrome were born to older mothers. This isn’t true either. Mostly because younger women have more babies. About 75% of babies born with Down syndrome are born to younger moms. However; about 9 % of babies are born to moms who are older than 35- but about 25% of babies born with Down syndrome are born into this group. My chances of having a baby with Down syndrome based on my age was about 1 in 1,250. (The average person’s chance of having a baby with autism are 1 in 110)
Like autism, the severity of Down syndrome is on a spectrum from mild to moderate disability. The characteristics of Down syndrome are recognizable at birth, like Abby’s were, but can range in degree. Abby has the slanted eyes, the lower set ears, shorter neck and flatter facial features. She does not have the simian crease in her palms, the bright spots in her eyes nor does she have club feet. She has a heart problem, but not the one that’s usually seen in children with Down syndrome. Over half of babies with Down syndrome have a heart defect that can be fixed through surgery or medications. This is another common misconception. Children with Down syndrome do not usually have to have surgery after surgery and definitely do not have miserable lives. I’ve heard this argument from those who think it’s okay to abort children with Ds, and it’s completely not true.
Another myth is that people with Down syndrome have a much shorter lifespan. Their numbers are now approaching the same as their peers without Ds.
90% of babies who are found to have Down syndrome during pregnancy are aborted. NINETY. I’ve said it before and I’ll say it until the day I die- there’s a special hell reserved for those who abort just because their baby is not their version of perfect.
Children “have” Down syndrome. I hate it when people say they “suffer from” or “are afflicted by” Down syndrome. Not true. Have you met Abby? That girl is not suffering at all.
Anyways, you’re now smarter. You’re welcome.
Lexi Mag 
Because Alzheimers is also on the 21st chromosome, they also have an extra chance of developing that. I can't remember what the said the percentage was, but it was up in the 80% range. They are just recently connected the 2, due to their longer life spans. One of the reasons I am grateful I had Eva at 27. I will (hopefully) be able to take care of her for the rest of my life. If not, she has a gaggle of siblings
Thanks! I'm glad to know that I already knew a lot of those facts. However I used to "know" a lot of the misconceptions. It's nice to be able to learn what the truth is. Oh, and I totally agree with you about people who would abort. That statistic makes me really, really sad.
Interesting. When I had a trisomy baby, they told me that the extra chromosome was left behind when an ovum erupted from the follicle, and could be "picked up" by an adjacent ovum. Never heard that it could happen after conception, though I do seem to remember having heard a theory that it was sometimes sperm related, though I can't as easily see how that would occur. Many syndromes seem to have possessive names, which is why I've always had difficulty remembering whether it's Down or Down's. Thanks for the clarification.
yeah. The reason for the Down's vs Down syndrome thing is this: While Down syndrome is listed in many dictionaries with both popular spellings (with or without an apostrophe s), the preferred usage in the United States is Down syndrome. This is because an “apostrophe s” connotes ownership or possession. Down syndrome is named for the English physician John Langdon Down, who characterized the condition, but did not have it. The AP Stylebook recommends using “Down syndrome,” as well.
Lexi, you're awesome! thank you for writing about your life in a way that is real, but focusing on the positive. I have really loved getting to know Abby from your posts. I really do think of you guys often, and hope things get a little bit easier. From one PPD survivor to another, we just do the best that we can, right?
Thanks for this post. I had a baby with 3 full sets of chromosomes. You'd think it would make a super baby or something, sadly, it does not. Our angel was XXY and didn't make it past 21 weeks. Explaining full triploidy is difficult and I have never done it as well as you have explained Down Syndrome.
Nice blogg thanks for posting