In biological systems, the addition of a methyl group to DNA, which can regulate the expression of genes. Some methylation changes are heritable.

A cytogenetic term that defines the “address” of the chromosomal deletion associated with FSHD Type 1. The deletion is on chromosome 4, on the “q” (long) arm at region 35.

A group of genes located in the 4q35 region, some whose activity is regulated by the D4Z4 repeat array.

An alternative genetic sequence at a given chromosome location, governing the same physical trait. Typically you inherit one allele form your mother and one allele from your father.

Proteins produced by the immune system, which bind specifically to unique features of other proteins and macromolecules.  Exploited by the immune system to destroy foreign materials, and by scientists to identify specific molecules.

Single stranded chains of nucleotides that bind to a specific sequence of RNA, thereby preventing its genetic information from being expressed.

The degradation of unnecessary or dysfunctional cellular components via the lysosome (compartments inside the cell that digest cellular waste).

The interaction of one molecule to another, which causes a change in the shape and function of the target molecule.

Objective measurements that indicate a patient’s health status, such as tests of muscle strength, a blood test, imaging, etc. Diagnostic biomarkers show if a person has a disease. Therapeutic biomarkers show if a therapy is having the desired effect.

The combination of DNA and proteins (primarily histones) that make up the contents of the nucleus of a cell. The main functions of chromatin are to package DNA into a smaller volume, to strengthen the DNA to allow cell division, to prevent DNA damage, and to control gene expression and DNA replication.