Single nucleotide polymorphism

A single nucleotide polymorphism (SNP) is a potential genetic mutation that occurs in a single spot in the human genome. A single spot in the human genome is represented physically by a particular nucleotide base-pair in the DNA, such as cytosine-guanine or adenine-thymine. For example, 60% of the general population may have a cytosine-guanine base pair at a particular location in their DNA, but 40% of the population may have a adenine-thymine base pair at that location instead. SNP's are often represented by an "rs" number, such as "rs53576".

Autoimmune
A 2020 study found two autoimmune-related SNPs associated with ME/CFS patients with an infectious onset.

PTPN22 rs2476601 aka R620W or C1858T (OR 1.63, CI 1.04–2.55, p = 0.016) - PTPNN22 (Tyrosine phosphatase non-receptor type 22)

CTLA4 rs3087243 (OR 1.53, CI 1.17–2.03, p = 0.001) - CTLA4 (Cytotoxic T-lymphocyte-associated protein 4)

PTPN22 rs2476601 has been found in multiple autoimmune diseases including Hashimoto's thyroiditis, psoriasis, and Type I diabetes.

Learn more

 * SNPedia's glossary
 * Genetic Science Learning Center