Question

Some variations between different human genomes are larger than SNPs. In nucleotide sequences, long duplications or deletions (often thousands of base pairs long) are known as _________.

Answer 1

Some variations between different human genomes are larger than SNPs. In nucleotide sequences, long duplications or deletions (often thousands of base pairs long) are known as COPY NUMBER VARIATION.

Chromosomes are vehicles of inheritance and reside inside the nucleus. The number and structure of chromosomal set is unique for each species of animals and plants. Any deviation in the number of rearrangement of chromosome segments causes abberations such as

• Single Nucleotide abberations,
• Indels,
• Copy Number Variations,
• Larger Structural Variations

These abberations result in abnormal phenotypes and disorders.

Copy number variation (CNV) is defined as duplications and deletions of gene sequences that typically range in length from 1,000 base pairs to 5 megabases. It is associated with gene expression and may cause phenotypic variations. Specific Copy Number Variations events can lead to Cancers, Schizophrenia, Autism,etc., Copy Number Variations are of two types

1. Copy number gain: Increase in copy number takes place due to genomic rearrangement like insertion / duplication
2. Copy Number Loss: Decrease in the number of genome due to deleterious rearraangement