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Reviewed October 2015
What is the official name of the MLH1 gene?
The official name of this gene is “mutL homolog 1.”
MLH1 is the gene's official symbol. The MLH1 gene is also known by other names, listed below.
Read more about gene names and symbols on the About page.
What is the normal function of the MLH1 gene?
The MLH1 gene provides instructions for making a protein that plays an essential role in DNA repair. This protein helps fix mistakes that are made when DNA is copied (DNA replication) in preparation for cell division. The MLH1 protein joins with another protein called PMS2 (produced from the PMS2 gene), to form a protein complex. This complex coordinates the activities of other proteins that repair mistakes made during DNA replication. The repairs are made by removing a section of DNA that contains mistakes and replacing the section with a corrected DNA sequence. The MLH1 gene is a member of a set of genes known as the mismatch repair (MMR) genes.
How are changes in the MLH1 gene related to health conditions?
Where is the MLH1 gene located?
Cytogenetic Location: 3p21.3
Molecular Location on chromosome 3: base pairs 36,993,350 to 37,050,846
(Homo sapiens Annotation Release 107, GRCh38.p2) (
The MLH1 gene is located on the short (p) arm of chromosome 3 at position 21.3.
More precisely, the MLH1 gene is located from base pair 36,993,350 to base pair 37,050,846 on chromosome 3.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about MLH1?
You and your healthcare professional may find the following resources about MLH1 helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
What other names do people use for the MLH1 gene or gene products?
See How are genetic conditions and genes named? in the Handbook.
Where can I find general information about genes?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding MLH1?
cancer ; cell ; cell division ; colon ; colorectal ; DNA ; DNA repair ; DNA replication ; duct ; E. coli ; endometrium ; gallbladder ; gene ; glioblastoma ; homozygous ; inherit ; inherited ; intestine ; leukemia ; lymphoma ; mutation ; ovarian ; population ; protein ; rectum ; stomach ; syndrome ; tumor
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (14 links)
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.