How is Robertsonian translocation diagnosed?
Robertsonian translocation type trisomy 13 can be detected by prenatal diagnosis technology, which inclue molecular cytogenetics and traditional karyotype analysis.
What happens in a Robertsonian translocation?
A Robertsonian translocation is one in which, effectively, the whole of a chromosome is joined end to end with another. This type of translocation involves only chromosomes 13, 14, 15, 21 and 22, because the ends of their short arms have similar repetitive DNA sequences that predispose to their fusion.
How is trisomy 21 diagnosed?
Trisomy 21 can be identified prenatally through screening tests such as non-invasive prenatal testing (NIPT) and ultrasound examinations. The diagnosis can be confirmed prenatally with better than 99% accuracy through chorionic villus sampling (CVS) or amniocentesis.
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.
How does Robertsonian translocation lead to trisomy?
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.
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 is chromosomal translocation detected?
There are multiple techniques to detect defining chromosomal translocations and other abnormalities, including conventional cytogenetic analysis, fluorescence in situ hybridization (FISH), spectral karyotyping (SKY), DNA microarray analysis, polymerase chain reaction (PCR) analysis, and immunohistochemical (IHC) …
What is the result of a Robertsonian translocation?
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.