What is the Difference Between Robertsonian and Reciprocal Translocation?

The main difference between Robertsonian and reciprocal translocation lies in the nature of the chromosomal rearrangements involved:

1. Reciprocal Translocation: In this type of translocation, two different chromosomes exchange segments with each other. The exchange occurs between non-homologous chromosomes, and the total chromosome number remains at 46. This rearrangement usually results in a balanced chromosomal structure, and the person carrying this pattern is normal and considered a translocation carrier. Reciprocal translocations are often harmless and may be detected in prenatal diagnosis. However, carriers of balanced reciprocal translocations may create gametes with unbalanced chromosomes, which can lead to infertility, miscarriages, or children with abnormalities.
2. Robertsonian Translocation: This type of translocation occurs when an entire chromosome attaches to another at the centromere. Robertsonian translocations usually involve acrocentric chromosomes, which are chromosomes with a centromere closer to one end than the other. In this case, the resulting chromosome structure is unbalanced, as there is a fusion of two chromosomes, leading to a loss of some genetic material. Robertsonian translocations are less common than reciprocal translocations and are more likely to cause diseases or abnormalities.

In summary, the key difference between Robertsonian and reciprocal translocation is that reciprocal translocation involves the exchange of genetic material between non-homologous chromosomes without causing a change in chromosome number, while Robertsonian translocation involves the fusion of entire chromosomes at the centromere, leading to a reduction in the usual chromosome number in a cell.

Comparative Table: Robertsonian vs Reciprocal Translocation

Here is a table comparing the differences between Robertsonian and reciprocal translocation:

Robertsonian translocation occurs in acrocentric chromosomes (14, 15, 21, and 22) and leads to the reduction of chromosome number due to the fusion of long arms and the loss of short arms. In contrast, reciprocal translocation refers to the exchange of genetic material between non-homologous chromosomes, resulting in two derivative chromosomes with translocated fragments but no change in the total chromosome number.