Is it possible for two people who have Down syndrome to give birth to a normal child? Explain.?

Answer 1

Good answer from the biologist, but most men with Down syndrome still usually have very low sperm count and almost never become fathers. So the answer is yes, a couple where both parents have DS can have a child without DS, but they're not likely to have a child at all.

The next question is why we're doing somebody else's homework for them!

Answer 2

Sorry to burst the bubble here but this is actually far more complex than the others who have posted make it seem.

I don’t know what you need this information for, if it's just for school use answer 1, if it's for you, or for university take a look at answer 2 (be warned, I haven't held back much with the scientific terminology, if you need it explained I bet wikipedia can help!)

1)
Most people with Down's syndrome have three copies of chromosome 21 where there should be only two. It is possible that sperm and eggs will be produced by the parents that contain only one of these chromosomes. When a sperm containing one copy of chromosome 21 and an egg containing one copy meet they will produce a healthy baby.

Statistically assuming random assortment the chances of each parent producing a "normal" sperm or egg is 50%. As a normal sperm and a normal egg need to meet we can calculate a 25% chance that the baby will be normal, a 50% chance that the baby will have 3 copies of chromosome 21 and will be Down's and a 25% chance that the baby will have 4 copies and will just die (4 copies is just too abnormal to survive!) I have tried to show this in the diagram below, as all other chromosomes are assumed to be normal I haven't included them.

Mum Dad
([21] [21] [21]) ([21] [21] [21])

Egg1 Egg2 Sperm 1 Sperm 2
([21] [21]) ([21]) ([21] [21]) ([21])

Egg 2 and Sperm 2 need to meet to produce a normal child.

If Egg 2 and Sperm 1, or Egg 1 and Sperm 2 meet then the child will have Down's

If Egg 1 and Sperm 1 meet the baby will spontaneously abort

2)

Down's is a chromosome disorder, not a genetic disorder as one poster seems to think. This means that there are multiple mechanisms for the development of Down's syndrome. The most common is to have inherited three copies of chromosome 21 rather than the standard two (As shown in part 1.) However there is always the possibility that a mistake during meiotic crossover has produced a Robertsonian translocation or an unbalanced translocation resulting in a partial (or complete) trisomy 21. Whilst most people believe that the genetic content of your cells is identical this is not always the case. Mosaicism is a condition where multiple cell lines exist within an individual. Differences here could result in major changes to both fertility and the extent of affliction with Down's.

In most normal healthy couples trying to conceive, there are a percentage of foetuses which are spontaneously aborted by the mother's body. This is may be because of a chromosome abnormality in the foetus or some other irregularity, but sometimes there is no obvious reason why the mother's body chose to terminate the pregnancy. Due to the inherent chromosome abnormality carried by the parents here, it is likely that most if not all foetuses are going to be aborted. The upshot of this however is that there is a huge selection pressure for foetuses to be karyotypicaly normal.

Putting it all together, some people with Down's can produce normal children, it depends the types of Down's syndrome that the parents carry.
Most Down's syndrome couples that are theoretically capable of producing children are only likely to produce a series of aborted foetuses due to the mother's body's reflex to terminate the pregnancies.

People with Down's syndrome have produced children, and in at least one case this child has been normal, however such cases are rare.

Answer 3

Women with Down syndrome can and do have children, but there is a 50 percent chance that their child will have Down syndrome. Men with Down syndrome are believed to be sterile, with only one documented instance of a male with Down syndrome who has fathered a child.
So if both the male and female have downs, they won't be able to have children due to his sterility, but in the unlikely event that they do, the child would have downs due to the recessive nature of the gene manifestation.

Answer 4

It is not likely that they could even produce a child. 50% of all males with down syndrome have undescended testes, the other half suffer from faulty sperm for the most part. Women with down syndrome can have children as their extra chromosome does not seem to affect their fertility.

Answer 5

confident. Downs capacity an extra chr 21. In meiosis to make egg/sperm, 4 eggs or 4 sperm are made: interior the woman a million/2 (or much less) of her eggs could have a typical supplement of chromosomes. comparable interior the boy: a million/2 of his sperm could have an x-chromosome, the different a million/2 would be male and ordinary. subsequently, a million/4 fertilized eggs could have a typical supplement of chromosomes. subsequently, a million/4 little ones would be ordinary. With in vitro fertilization Drs can be certain a typical toddler is implanted. Of, direction, a Downs toddler is as magnificent as any. yet in vitro is a thank you to pick for or against an extra set of chr 21.