*1.1.1.11 Single nucleotide polymorphism (SNP)*

Heritable polymorphism resulting from a single base pair change. SNPs generally have only two alleles.

#### *1.1.1.12 Linkage*

In genetics, refers to how two genes that are nearby to one another on the same chromosome are often inherited together (Glossary. Nature) [9].

#### *1.1.1.13 Linkage disequilibrium*

Describes the state of two genotypes at different loci being dependent, showing a correlation; does not require gene linkage (Glossary. Nature) [9].

### *1.1.1.14 Linkage equilibrium*

The association of two alleles at two or more loci at the frequency predicted by their individual frequencies (Glossary. Nature) [9].

### *1.1.1.15 Segregational analysis*

The process of fitting formal genetic models to data on expressed disease characteristics (phenotype) in biological family members in order to determine the most likely mode of inheritance for the trait or disease under study. (NCI"s Dictionary of Genetic terms) [10].

### *1.1.1.16 Histone modification*

A histone modification is a covalent post-translational modification (PTM) to histone proteins which includes methylation, phosphorylation, acetylation, ubiquitylation, and sumoylation. The PTMs made to histones can impact gene expression by altering chromatin structure or recruiting histone modifiers. (What is epigenetics).

### *1.1.1.17 Linkage analysis*

Study aimed at establishing linkage between genes. Today linkage analysis serves as a way of gene-hunting and genetic testing (Webster's New World medical dictionary) [11].
