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EHMT1 gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

EHMT1 gene

The EHMT1 gene provides instructions for making an enzyme that modifies histones to regulate gene activity, which is essential for normal development.

Normal Function

The EHMT1 gene provides instructions for making an enzyme called euchromatic histone methyltransferase 1. Histone methyltransferases are enzymes that modify proteins called histones. Histones are structural proteins that attach (bind) to DNA and give chromosomes their shape. By adding a molecule called a methyl group to histones, histone methyltransferases can turn off (suppress) the activity of certain genes, which is essential for normal development and function.

Health Conditions Related to Genetic Changes

Kleefstra syndrome

Kleefstra syndrome, a disorder affecting many parts of the body, is caused by the loss of the EHMT1 gene or by mutations that disable its function.

  • Most people with Kleefstra syndrome are missing a sequence of about 1 million DNA building blocks (base pairs) on one copy of chromosome 9 in each cell. The deletion occurs near the end of the long (q) arm of the chromosome at a location designated q34.3, a region containing the EHMT1 gene.
  • The loss of the EHMT1 gene from one copy of chromosome 9 in each cell is believed to be responsible for the characteristic features of Kleefstra syndrome.
  • About 25 percent of individuals with Kleefstra syndrome do not have a deletion of genetic material from chromosome 9; instead, these individuals have mutations in the EHMT1 gene.
  • These mutations may change single amino acids, create a premature stop signal, or alter the way the gene's instructions are pieced together. These changes generally result in an enzyme that is unstable and decays rapidly, or that is disabled and cannot function properly.

Either a deletion or a mutation affecting the EHMT1 gene results in a lack of functional euchromatic histone methyltransferase 1 enzyme. A lack of this enzyme impairs proper control of the activity of certain genes in many of the body's organs and tissues, resulting in the abnormalities of development and function characteristic of Kleefstra syndrome.

Frequently Asked Questions

Both deletions and pathogenic point mutations (missense, nonsense, splice‑site) typically result in loss‑of‑function of the EHMT1 protein and produce a similar clinical spectrum. The exact mutation type does not usually alter the overall prognosis, but some individuals with milder missense changes may have slightly higher functional ability. Treatment remains supportive and symptom‑directed; there are currently no mutation‑specific therapies. Genetic counseling can explain the specific variant and its expected impact.
EHMT1 encodes a histone methyltransferase that helps turn off specific genes during brain development. Losing one copy (haploinsufficiency) reduces the amount of functional enzyme, leading to the characteristic features of Kleefstra syndrome: developmental delay, speech impairment, low muscle tone, distinctive facial features, and sometimes heart or kidney anomalies. Management focuses on early intervention—speech and occupational therapy, individualized education plans, regular cardiac and renal evaluations, and monitoring for seizures. A multidisciplinary team (genetics, neurology, cardiology, developmental pediatrics) provides the most comprehensive care.
Kleefstra syndrome is usually caused by a de novo deletion, but when a parent carries the same deletion (as in your case), the inheritance follows an autosomal dominant pattern. Each pregnancy carries a 50 % chance of inheriting the deleted copy. Prenatal options include chorionic villus sampling (10‑12 weeks) or amniocentesis (15‑18 weeks) with targeted testing for the known EHMT1 deletion, as well as non‑invasive prenatal testing (NIPT) if the deletion is large enough to be detected. Pre‑implantation genetic testing (PGT‑M) with IVF is another way to select embryos without the deletion.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

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