An individual who has at a particular locus a pathogenic variant on one chromosome and a wild type allele on the other chromosome, and who has findings of the disorder; generally refers to a clinically affected female with a heterozygous pathogenic variant in an X-linked gene. The phenotype is usually less severe than in a hemizygous male with the same pathogenic variant.

Related terms: carrier; heterozygote; X-chromosome inactivation; X-linked