Introduction to Variant analysis

Contributors

Authors: Bérénice Batut Yvan Le Bras

What is Exome sequencing?

Exome sequencing

= Whole exome sequencing (WES or WXS)

Sequencing of all expressed protein-coding genes in a genome

Exome in Humans

• ~180,000 exons
• 1% of the human genome
• ~30 million base pairs

Goal of exome sequencing

Identify genetic variation that is responsible for both Mendelian and common diseases without the high costs associated with whole-genome sequencing

Exome sequencing is the most efficient way to identify the genetic variants in all of an individual’s genes

Limits

Exome sequencing can not identify genetic variation in

• All genes
• Mitochondrial genes
• “Structural variants”
• Triplet repeat disorders
• Other copy number variants
• Introns
• “Uniparental disomy”
• Control sequences
• Epigenetic changes
• Gene-gene (epistatic) interactions

2 tutorials for training on exome sequencing data analysis

Same goal

Identify and annotate genetic variants in a family with two parents and a child exome data

Similar data analysis approach

### 2 tutorials

• Introductory tutorial
• Detailed tutorial

Thank you!