CMMRD is associated with which type of inheritance?

CMMRD, or Constitutional Mismatch Repair Deficiency, is correctly linked with autosomal recessive inheritance. This condition is caused by biallelic mutations in mismatch repair genes such as MSH2, MSH6, PMS2, and MLH1, which are inherited from both parents.

For an individual to express a recessive condition like CMMRD, it is necessary for both copies of the gene (one from each parent) to be mutated or non-functional. If an individual inherits one normal allele and one mutated allele, they will be a carrier but typically will not exhibit symptoms of the condition. Therefore, the characteristic inheritance pattern of CMMRD aligns with autosomal recessive inheritance.

Understanding this is crucial for genetic counseling, as it allows clinicians to identify potential risks for offspring of affected individuals and suggest testing for those at risk.