Difference Between Paracentric and Pericentric Inversion

The key difference between paracentric and pericentric inversion is that in paracentric inversion, a chromosomal segment that does not contain the centromere region rearranges in reverse orientation, while in pericentric inversion, a chromosomal segment containing the centromere rearranges in reverse orientation.

Inversion is a type of chromosome rearrangement and a chromosomal mutation. During an inversion, a part of the chromosome breaks and reinserts after turning 180 degrees. Thus, rearrangement occurs in a reversed manner. The broken chromosomal segment has reversed orientation after reinsertion. There are two types of inversions as paracentric inversion and pericentric inversion. Paracentric inversion occurs in one arm of the chromosome while pericentric inversion occurs in both arms.

CONTENTS

1. Overview and Key Difference
2. What is Paracentric Inversion
3. What is Pericentric Inversion
4. Similarities Between Paracentric and Pericentric Inversion
5. Side by Side Comparison – Paracentric vs Pericentric Inversion in Tabular Form
6. Summary

What is Paracentric Inversion?

Paracentric inversion is one of the two types of chromosomal inversions. It occurs in one arm of the chromosome. Since both breaking points are present in one arm, this inversion does not include the centromere. Furthermore, the broken segment of the chromosome is rearranged in reverse orientation, as shown in the following figure.

What is Pericentric Inversion?

Pericentric inversion is the second type of chromosomal inversion. It occurs in both arms of the chromosome. Since there is a breaking point in each arm, the breakage occurs in both sides of the centromere. Thus, pericentric inversion includes the centromere.

As shown in the above figure, a segment including the centromere rearranges in reverse orientation during the pericentric inversion.

What are the Similarities Between Paracentric and Pericentric Inversion?

• Paracentric and pericentric inversions are the two main types of inversions.
• Both are also large scale chromosomal mutations.
• They occur within a single chromosome.
• Moreover, both types of inversions do not cause a loss of genetic information.
• They simply rearrange the linear gene sequence of a chromosome.

What is the Difference Between Paracentric and Pericentric Inversion?

Paracentric inversion does not include the centromere, and both breaks occur in one arm of the chromosome while pericentric inversion includes the centromere, and there is a breakpoint in each arm. So, this is the key difference between paracentric and pericentric inversion.

Below infographic summarizes the difference between paracentric and pericentric inversion.

Summary – Paracentric vs Pericentric Inversion

Inversion is a large scale chromosomal mutation. Inversion reverses the orientation of a chromosomal segment after its breakage. Paracentric and pericentric inversion are two types of inversions. Paracentric inversion does not include the centromere region while pericentric inversion occurs in a chromosome segment, including the centromere region. Therefore, this is the key difference between paracentric and pericentric inversion. Moreover, both breaking points lie in one arm of the chromosome in paracentric inversion while there is a breaking point in each arm of the chromosome in pericentric inversion.

Reference:

1.“Chromosomal Inversion.” Wikipedia, Wikimedia Foundation, 3 Aug. 2019, Available here.