What is the Difference Between Nullisomy and Double Monosomy?

Nullisomy and double monosomy are both aneuploidy conditions, which are abnormal changes in the number of chromosomes in a cell. They differ in the number of chromosomes lost in each case.

• Nullisomy: In nullisomy, both chromosomes in a pair of homologous chromosomes are missing. This results in a chromosomal composition of 2n-2. Nullisomy is a condition where individuals are called nullisomics.
• Double Monosomy: In double monosomy, one chromosome from each of two pairs of homologous chromosomes is missing. This results in a chromosomal composition of 2n-1-1.

In summary, the main difference between nullisomy and double monosomy is the number of chromosomes lost in each condition:

• In nullisomy, both chromosomes of a homologous chromosome pair are missing (2n-2).
• In double monosomy, one chromosome from each of two pairs of homologous chromosomes is missing (2n-1-1).

Comparative Table: Nullisomy vs Double Monosomy

Here is a table summarizing the differences between nullisomy and double monosomy:

Both nullisomy and double monosomy are types of aneuploidy, which is a mutation in which the chromosomal number is abnormal, changing the total number of chromosomes in a set. They produce abnormal chromosome numbers and disrupt the overall gene balance in the chromosome set.