Question

Epigenetics and Imprinting:

How do you distinguish chromatin variants from sequence variants (classical mutation) in the context of GOF and/or LOF?

Answer 1

A sequence variant is a term covering any unintentional amino acid omissions, substitutions or insertions during protein biosynthesis. Mutation can lead to changes in protein functions. Through these genetic mutations, a protein can lose its native function ie., loss-of-function, (LoF), or it can confer a new function ie., gain-of-function, (GoF). However, when a mutation occurs, it is difficult to determine whether it will result in a LoF or a GoF. A mutation refers to a change of the genomic sequence. LoF and GoF mutations alterations of the genome can lead to changes of protein functions. LoF variant showed some properties such as the allele frequency and the degrees of associations with diseases. They also showed the effects of LoF variants, including phenotypes, diseases and gene expressions.  Chromatin varients have an impact on DNA methylation. Moreover a deletion or insertion can impact epigenetic marks in neighbouring sequences.