What is meant by Robertsonian translocation?
Robertsonian translocation is the most common form of chromosomal translocation in humans. It means that two chromosomes, the structures that make up a person’s DNA, join together in an abnormal way. About 1 in 1,000 people are born with a Robertsonian translocation.
What is Robertsonian translocation karyotype?
In Robertsonian translocation, the pericentric regions of two acrocentric chromosomes fuse to form a single centromere or two. The resulting balanced karyotype has only 45 chromosomes including the translocated one, which is the result of a fusion of the long arms of two acrocentric chromosomes (5).
Is Trisomy 13 a translocation?
In about 20 percent of affected individuals, trisomy 13 results from a translocation involving chromosome 13 and another chromosome. Translocations occur when regions of certain chromosomes break off and are rearranged, resulting in shifting of genetic material and an altered set of chromosomes.
Where does Robertsonian translocation occur?
Robertsonian Chromosome Translocation. Robertsonian translocations occur between two acrocentric chromosomes, which are chromosomes in which the centromere is close to one end of the chromosome, resulting in a small (p for petit) length of genetic material beyond the centromere.
What is Robertsonian translocation give example?
A Robertsonian translocation results when the long arms of two acrocentric chromosomes fuse at the centromere and the two short arms are lost. If, for example, the long arms of chromosomes 13 and 14 fuse, no significant genetic material is lost—and the person is completely normal in spite of the translocation.
What is the most common Robertsonian translocation?
Introduction
- Robertsonian translocations (centric fusion of two acrocentric chromosomes) occur with a prevalence of ∼1 in 1000 in the general population (Gardner and Sutherland, 1996).
- The most common Robertsonian translocation is between chromosomes 13 and 14.
What is the life expectancy of Robertsonian translocation?
Babies born with Patau syndrome rarely live more than one year. Other monosomies and trisomies that can occur with Robertsonian translocations are nonviable. This is why having a Robertsonian translocation goes along with a higher risk of miscarriage.
How old is the oldest person with trisomy 13?
No mosaicism was detected in repeated cytogenetic studies. The 19-year-old patient is the oldest known living person with regular trisomy 13.
Do babies with trisomy 13 suffer?
Patau’s syndrome (trisomy 13) is a rare condition, associated with high mortality, a range of congenital abnormalities, and severe physical and cognitive impairment. Many affected pregnancies will miscarry, and most babies born with the condition will not survive more than a few days or weeks.
What is Robertsonian translocation symptoms?
In most cases, there are no symptoms or visible signs of a Robertsonian translocation. Depending on where in your DNA the translocation occurs, it’s very likely that you won’t experience any side effects of your DNA chain being atypical.
How does translocation affect offspring?
Individuals who carry a balanced translocation are at risk of having recurrent miscarriages or indeed a child with congenital abnormalities and/or learning difficulties as the offspring might inherit an unbalanced form of the translocation.
Who has lived the longest with trisomy 13?
Survival beyond 3 years is an exception in regular trisomy-I3 patients. The oldest well-documented living case of trisomy-13 was reported by Marden and Yunis [6] in 1967. She was 10 years old at that time. There have been a few other reports [7] of unusually prolonged survival of trisomy-13 patients.
Which is the best definition of Robertsonian translocation?
robertsonian translocation – translocation in which the centromeres of two acrocentric chromosomes appear to have fused, forming an abnormal chromosome. Synonym(s): centric fusion.
What causes a 13 14 14 Rob translocation?
ROB translocation is caused by joining together of two acrocentric chromosomes which are 13, 14, 15, 21 and 22, while the most common one is between 13 and 14 at a frequency of 75%. At the process the participating chromosomes break at the centromere, and lose their short arms.
When does a Robertsonian translocation lead to trisomy 13?
Robertsonian translocations between chromosomes 13 and 14 (when transmitted in unbalanced for may lead to Trisomy 13) lead to the trisomy 13 (Patau) syndrome. And the Robertsonian translocations between 14 and 21 and between 21 and 22 (may result in Trisomy 21) in Down syndrome.
How is Patau syndrome related to Robertsonian translocation?
Patau syndrome is a result of an extra copy of chromosome 13 in a developing fetus’s DNA. 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.
