Translocation 21;21 / Robertsonian Translocation

I get a lot of hits on my blog on the following topics:

Translocation Down syndrome
Translocation 21;21
Translocation Carrier
Trisomy 21 Translocation
Karyotype trisomy 21 translocation
Translocation 21 Trisomy

As Translocation 21;21 is very rare, and a lot of people seem to be googling this, I decided to set up a yahoo mail group for parents, families, friends, individuals, experts with Translocation 21,21 experience who wants to share their experience/learn more about Translocation 21;21.

If you are interested to join send me an email at cmolin77[at] or click here!

If you want to see what a Translocation 21;21 kariyotype looks like, click here.
In short, if you are a carrier of T21;21 there is a 100% chance of all your babies having DS. There is no other way with this type of Translocation.

From the following web page you can read about T21,T21  and it is a little more descriptive of what Translocational T21/DS really is:

Translocation Down syndrome refers to the rearranged chromosome material. There are three # 21 chromosomes, just like there are in trisomy 21, but one of the 21 chromosomes is attached to another chromosome, instead of being separate. The extra # 21 chromosome is what causes the problems that make up Down syndrome. In translocation Down syndrome, the extra 21 chromosome may be attached to the #14 chromosome, or to #s13, 15, or 22. In some cases, two #21 chromosomes can be attached to each other.

Three to 4 percent of babies born with Down syndrome have translocation Down syndrome. If you had a roomful of 100 babies with Down syndrome, they would all look alike and have similar features and health problems. You would not be able to pick out the three or four that have a translocation.

Whenever a translocation is found in a child, the parents’ chromosomes are studied to determine whether the translocation was inherited or not. If one parent has the translocation chromosome, then the physician knows the baby inherited the translocation from that parent. The parent will actually have 45 total chromosomes in each cell of their body, but they will be normal and healthy because they still have only two copies of each chromosome. When a person has a rearrangement of chromosome material, with no extra or missing chromosome material, they are said to have a “balanced translocation” or be a “balanced translocation carrier.”

Parents with balanced translocations may have fertility problems (trouble becoming pregnant), miscarriages, or have an increased chance of having a child with health problems. Although the parent can donate the proper amount of genetic material (23 chromosomes) to a pregnancy, they have a risk of donating too much or too little genetic material to a pregnancy. It is not something they can control or predict. The chance depends on the type of chromosome rearrangement and which chromosomes are involved. For example, if the translocation is between #14 and 21, there is a 10 to 15 percent chance for Down syndrome in a pregnancy if the mother is the translocation carrier, and a 3 to 5 percent chance if the father is the translocation carrier. The chances are different for men and women because sperm and eggs are produced differently. A woman is born with all of the eggs she will ever have while men are constantly producing new sperm.

There is another important factor to remember when a parent is found to have a translocation. The parents’ relatives (brothers, sisters) may also have inherited the translocation and, therefore, may have the same risks for problems with a pregnancy. For these reasons, it is recommended that people with chromosome rearrangements share this information with their relatives so that they can have the option of having their chromosomes studied.

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20 Responses

  1. Jag vill vara med, jag vill vara med!!! Räknar in mig i grupperna family, friend och expert. Och faktiskt NÄSTAN parent.

  2. Vilken bra idé! Vad får du allt ifrån Kicki? Måste varit Vänersborgsluften du andades som barn. Hihi. Puss.

  3. Kickidarling, har du sett att DN har en artikelserie om barn med Downs syndrom och deras föräldrar?

  4. Hi , My son Aaron is 12 and has translocation DS 21,21 break points 22,22. We live in the uk England, your son looks lovely , Aaron is doing well too. He is normal height but has a diagnosis of Autism and Type 1 Diabetes,

    • Hi
      Have just found this site and your note caught my attention. I have twin boys who are 4 next month, ethan has translocation DS 21 21 and his specialists are now beginning to think he may be autistic too.
      Do you have any info on this specific type of DS and any poss link with autism?
      We live near to Bristol in england.

    • That is very good…. God Bless

      • God Bless and thqat is good that your family and kids are getting well that have this

  5. My oldest daughter has 21:21 translocation and it is not because either her father or I are carriers. It’s simply something that happened in meiosis. I have had one child since and she is completely “typical”.

  6. Hi, my daughter is 19months old. We found out that she has 21-21, and that my husband is the carrier. We have a 100% chance of having other children with DS.

    It is hard as parents and a couple to handle this but we are now making decisions that feel best for our family (vasectomy). We have never met anyone with this, and all of the doctors we talk to have never seen it. It is really rare, but it is real.

    Thank you for putting this up. Many people do not believe us when asked about 21-21. It’s comforting to know that people do realize it exists.

  7. […] 5. Translocation 21;21/Robertsonian Translocation (also containing info on joining the T21;21 yahoo in… […]

  8. Thank you for posting this information. It was really helpful. I did not know this type of balanced Robertsonian Translocation existed.

  9. My daughter has 21:21 translocation, both myself and my husband have had our blood tested and both are normal. We are eager to find out more about this type of translocation as it seems it is very rare, this website is very helpful, thank you.

    My daughter is 6 weeks old and is absolutely beautiful, very wide eyed and taking everything in. We really are blessed to have her.

  10. Evie-Mae has trisomy 21 translocation 21:21,her karyotype is 46,xx,der(21)qter->q22.1::p11.2->qter) we have been told she has just 46 chromosome’s but on one of her 21 chromosome’s she has a 3rd ds critical region and have classed her as trisomy 21 translocation 21:21, have you heard of this before?( my wife wrote the reply above : july 4th 2011)

  11. […] 5. Translocation 21;21/Robertsonian Translocation (also containing info on joining the T21;21 yahoo in… […]

  12. My daughter is a down syndrome girl with 21:21translocation,she is 2 years old ,very cute and clever.I always find the reason why we have more 21q to her?but there is no answer.

  13. Hi

    Our son who is now 1 year old has an 21/21 translocation breakpoint 10. We are from the Netherlands. We also have a son who has no extra 21 chromosome. We still need to do some blood tests…

    • hi, our son aeymad is now 22 years old, ans he too is a translocation 21/21 Downer. I do not know if you have been looking at the programm synDROOM from Johnny de Mol??? on octobre 10th he was the one who rapped with Ali B.
      it is not a heritad case, we just were lucky.

  14. Hi my daughter was born on the 9th may 2017 and her blood was taken which returned as the krototype 46,xy,21:21,q10:10 trisomy associated with robertsonian translocation.I have not get taken her to an occupational therapist.any suggestion you might have?

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