What is an unbalanced translocation?
An unbalanced translocation occurs when a fetus inherits a chromosome with extra or missing genetic material from a parent with a balanced translocation.
Is translocation balanced or unbalanced?
Translocations can be balanced (in an even exchange of material with no genetic information extra or missing, and ideally full functionality) or unbalanced (where the exchange of chromosome material is unequal resulting in extra or missing genes).
What is the difference between Robertsonian and reciprocal translocation?
There are two main types of translocations: reciprocal and Robertsonian. In a reciprocal translocation, two different chromosomes have exchanged segments with each other. In a Robertsonian translocation, an entire chromosome attaches to another at the centromere.
What is Robertsonian translocation Down syndrome?
The Robertsonian translocation is unbalanced and the baby has three copies of the long arm of chromosome 21 instead of two. This causes a type of Down’s syndrome called translocation Down’s syndrome. The effects on the baby are exactly the same as when Down’s syndrome is caused by having an extra entire chromosome 21.
What is the difference between a balanced and an unbalanced Robertsonian translocation?
In balanced form, a Robertsonian translocation takes the place of two acrocentric chromosomes and results in no problems for the person carrying it. But in unbalanced form, Robertsonian translocations produce chromosome imbalance and cause syndrome of multiple malformations and mental retardation.
Is Robertsonian translocation balanced or unbalanced?
The Robertsonian translocation is unbalanced and the baby has three copies of the long arm of chromosome 21 instead of two. This causes a type of Down’s syndrome called translocation Down’s syndrome.
Is Robertsonian translocation reciprocal?
Can NIPT detect Robertsonian translocation?
In 2-4% of cases Down’s Syndrome is due to a Robertsonian translocation. In theory, NIPT tests are designed to provide risk assessment based on whether a third copy of chromosome 21 is present, regardless of this being due to a Robertsonian translocation or free trisomy.