A carrier is a term used when talking about autosomal recessive inheritance, and is a person who has a copy of a gene with a mutation but does not have CMT or symptoms. In autosomal recessive inheritance, both copies of the gene need to have a mutation. Carriers only have one copy with a mutation. If two carriers of a condition have a child, there is a 1 in 4 or 25% chance of that child having the condition in question.