C9orf72 Gene and Amyotrophic Lateral Sclerosis: Clinical Trials
The C9orf72 gene sits on chromosome 9p21.2, and its full name is C9orf72-SMCR8 complex subunit. Orphanet links C9orf72 to 6 rare conditions and lists variants in the gene as a cause of 3 of them. Trial Friend's Amyotrophic Lateral Sclerosis page lists C9orf72 among the genes behind the condition. As of September 29, 2026, 8 recruiting or soon-opening trials on ClinicalTrials.gov name C9orf72 as a gene.
Other symbols for C9orf72 in gene databases: DENND9, DENNL72, MGC23980.
What the C9orf72 gene does
C9orf72 makes a protein found in many tissues and plentiful in nerve cells, where it is thought to help cells make, use and move RNA. The gene holds a short stretch of DNA letters, GGGGCC, that can repeat, and up to about 30 repeats are thought to cause no harm.
Summarized from the C9orf72 page on MedlinePlus Genetics, U.S. National Library of Medicine, checked September 29, 2026.
C9orf72 and Amyotrophic Lateral Sclerosis
These condition pages list C9orf72 among the genes behind the condition, checked against genetics references when each page was written.
One disease-causing variant can be enough to cause the condition.
About 90 to 95% of ALS is sporadic; among familial cases, C9orf72 repeat expansions account for 30 to 40% and SOD1 for 15 to 20%, and a cause is found in about 60%.
C9orf72 mutation clinical trials
These recruiting or soon-opening trials mention C9orf72 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.
8 trials, checked September 29, 2026. The list refreshes from ClinicalTrials.gov every few hours.
All conditions linked to C9orf72 gene mutations
Orphanet records how each gene relates to each condition. Orphanet links C9orf72 to 6 rare conditions and lists variants in the gene as a cause of 3 of them.
- Causes it. Disease-causing variants in this gene are a direct cause of the condition.
- Raises risk. Some variants raise the chance of the condition without guaranteeing it.
C9orf72 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 C9orf72.
C9orf72 gene questions
What does the C9orf72 gene do?
C9orf72 makes a protein found in many tissues and plentiful in nerve cells, where it is thought to help cells make, use and move RNA. The gene holds a short stretch of DNA letters, GGGGCC, that can repeat, and up to about 30 repeats are thought to cause no harm. This summary follows MedlinePlus Genetics from the U.S. National Library of Medicine.
Are there clinical trials for people with C9orf72 gene variants?
As of September 29, 2026, 8 recruiting or soon-opening trials on ClinicalTrials.gov name C9orf72 as a gene. Each one is listed on this page with the words from the trial that mention the gene. ClinicalTrials.gov also lists 230 open trials for Amyotrophic Lateral Sclerosis, and Match Me on Trial Friend can check those against age, sex, location and treatment history.
What conditions are linked to the C9orf72 gene?
Orphanet links C9orf72 to 6 rare conditions and lists variants in the gene as a cause of 3 of them. They include Amyotrophic lateral sclerosis, Frontotemporal dementia with motor neuron disease, Huntington disease-like syndrome due to C9ORF72 expansions, Behavioral variant of frontotemporal dementia, Progressive non-fluent aphasia and Semantic dementia. Orphanet is the European rare disease database run by INSERM in Paris.
How is Amyotrophic Lateral Sclerosis inherited?
The inheritance pattern is autosomal dominant. One disease-causing variant can be enough to cause the condition. About 90 to 95% of ALS is sporadic; among familial cases, C9orf72 repeat expansions account for 30 to 40% and SOD1 for 15 to 20%, and a cause is found in about 60%.
What does a C9orf72 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.
- C9orf72 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.