MECP2 Gene and Rett Syndrome: Mutations and Clinical Trials
The MECP2 gene sits on chromosome Xq28, and its full name is methyl-CpG binding protein 2. Orphanet links MECP2 to 7 rare conditions and lists variants in the gene as a cause of 5 of them. Trial Friend's Rett Syndrome page lists MECP2 among the genes behind the condition. As of September 29, 2026, 12 recruiting or soon-opening trials on ClinicalTrials.gov name MECP2 as a gene.
What the MECP2 gene does
MECP2 makes the MeCP2 protein, which helps control when other genes are active. It is especially plentiful in brain cells, where it appears to help maintain the connections between nerve cells.
Summarized from the MECP2 page on MedlinePlus Genetics, U.S. National Library of Medicine, checked September 29, 2026.
MECP2 and Rett Syndrome
These condition pages list MECP2 among the genes behind the condition, checked against genetics references when each page was written.
The gene is on the X chromosome, and one variant can cause the condition in males or females. Most cases are new variants rather than inherited.
More than 99% of cases have no family history; CDKL5 and FOXG1 disorders were once called Rett variants but are now classed separately.
MECP2 mutation clinical trials
These recruiting or soon-opening trials mention MECP2 as a gene in their title, summary, eligibility rules or keywords. Some want people with a variant in it, and others study it more broadly, which is why each trial's own words are shown. In cancer trials the gene change is usually one found in the tumor rather than one a person inherited.
12 trials, checked September 29, 2026. The list refreshes from ClinicalTrials.gov every few hours.
All conditions linked to MECP2 gene mutations
Orphanet records how each gene relates to each condition. Orphanet links MECP2 to 7 rare conditions and lists variants in the gene as a cause of 5 of them.
- Causes it. Disease-causing variants in this gene are a direct cause of the condition.
- Plays a part. Orphanet lists the gene as shaping the condition, often as one of several genes in a missing or extra piece of a chromosome.
- Raises risk. Some variants raise the chance of the condition without guaranteeing it.
MECP2 genetic test results and what a variant can mean
Labs sort each variant they find into 5 groups, from pathogenic and likely pathogenic through uncertain significance to likely benign and benign. Only the first 2 are usually treated as the cause of a condition. A variant of uncertain significance, or VUS, is one without enough evidence either way yet, and labs can reclassify it as research builds.
A genetic counselor or your doctor can explain what a specific result means for you and your family. Our genetic testing guide covers the terms, and MedlinePlus Genetics from the National Library of Medicine has a plain-language page on MECP2.
MECP2 gene questions
What does the MECP2 gene do?
MECP2 makes the MeCP2 protein, which helps control when other genes are active. It is especially plentiful in brain cells, where it appears to help maintain the connections between nerve cells. This summary follows MedlinePlus Genetics from the U.S. National Library of Medicine.
Are there clinical trials for people with MECP2 gene variants?
As of September 29, 2026, 12 recruiting or soon-opening trials on ClinicalTrials.gov name MECP2 as a gene. Each one is listed on this page with the words from the trial that mention the gene. ClinicalTrials.gov also lists 17 open trials for Rett Syndrome, and Match Me on Trial Friend can check those against age, sex, location and treatment history.
What conditions are linked to the MECP2 gene?
Orphanet links MECP2 to 7 rare conditions and lists variants in the gene as a cause of 5 of them. They include Atypical Rett syndrome, Rett syndrome, MECP2-related severe neonatal encephalopathy, X-linked intellectual disability-psychosis-macroorchidism syndrome, X-linked non-syndromic intellectual disability, Proximal Xq28 duplication syndrome and 1 more. Orphanet is the European rare disease database run by INSERM in Paris.
How is Rett Syndrome inherited?
The inheritance pattern is X-linked dominant, usually de novo. The gene is on the X chromosome, and one variant can cause the condition in males or females. Most cases are new variants rather than inherited. More than 99% of cases have no family history; CDKL5 and FOXG1 disorders were once called Rett variants but are now classed separately.
What does an MECP2 variant of uncertain significance mean?
A variant of uncertain significance, or VUS, is a change in the gene that labs don't yet have enough evidence to call disease-causing or harmless. It is not used on its own to diagnose a condition, and labs can reclassify it as research builds. A genetic counselor can explain what a specific result means for you and your family.
Sources
- Gene and condition links from Orphadata (Orphanet, INSERM US14), used under CC BY 4.0, read September 29, 2026.
- Trials from ClinicalTrials.gov, read September 29, 2026.
- MECP2 gene, MedlinePlus Genetics, U.S. National Library of Medicine.
- Inheritance and gene notes from the Trial Friend condition pages above, each checked against genetics references.
Other gene pages
The gene search covers every gene Orphanet links to a rare disease.