Table of Contents
How many chromosomes are there in cells of carriers of Robertsonian translocation involving 14 and 21 chromosomes?
The translocation chromosome replaces one of the normal acrocentric chromosomes, and the karyotype of a Down syndrome patient with a Robertsonian translocation between chromosomes 14 and 21 is therefore 46,XX or XY,rob(14;21)(q10;q10),+21 (seeTable 5-1 for nomenclature).
When translocation is the cause of trisomy 21?
Translocation Down syndrome refers to the type of Down syndrome that is caused by rearranged chromosome material. In this case, 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.
Can people with Robertsonian translocation have children?
Many people with Robertsonian translocation have healthy children. The condition can, however, impact on their chances of having a family. Women with the translocation may find it difficult to get pregnant. They also have a higher chance of having a miscarriage than those without Robertsonian translocation.
How common is Robertsonian translocation?
Robertsonian translocations, fusions between two acrocentric chromosomes, are the most common structural chromosomal rearrangements in humans and occur in approximately 1 in every 1000 newborns [1].
How common is translocation Down syndrome?
Translocation Down syndrome: This type accounts for a small percentage of people with Down syndrome (about 3%). This occurs when an extra part or a whole extra chromosome 21 is present, but it is attached or “trans-located” to a different chromosome rather than being a separate chromosome 21.
Are translocations inherited?
A translocation is either inherited from a parent or happens around the time of conception. A translocation cannot be corrected – it is present for life. A translocation is not something that can be “caught” from other people. Therefore a translocation carrier can still be a blood donor, for example.
What is Robertsonian translocation of chromosomes?
In Robertsonian translocation, the two long arms of two separate acrocentric chromosomes fuse to create one chromosome. The short arms are usually lost. This is sometimes called centric-fusion translocation. Chromosomes 13 and 14, 13 and 21, or 21 and 22 fusing are the most common forms of Robertsonian translocation.
What are the possible consequences of Robertsonian translocation?
Consequences. About one in a thousand newborns have a Robertsonian translocation. The most frequent forms of Robertsonian translocations are between chromosomes 13 and 14, 14 and 21, and 14 and 15. A Robertsonian translocation in balanced form results in no excess or deficit of genetic material and causes no health difficulties.
Can Robertsonian translocation cause Patau syndrome?
If your Robertsonian translocation fuses chromosome 13 with another chromosome, you may be a carrier for Patau syndrome. Most cases of this trisomy aren’t inherited, but it’s possible. In about 20 percent of cases of Patau syndrome, a translocation plays a part in the syndrome’s appearance.
Can Down syndrome be inherited from Robertsonian translocation?
Down syndrome and more. If your Robertsonian translocation fuses chromosome 13 with another chromosome, you may be a carrier for Patau syndrome. Most cases of this trisomy aren’t inherited, but it’s possible. In about 20 percent of cases of Patau syndrome, a translocation plays a part in the syndrome’s appearance.