X-linked inheritance X-linked recessive inheritance An X-linked recessive condition would be curated as monoallelic_X_hemizygous and we would understand that those diseases are most commonly observed in males and may not fully manifest when heterozygous in females. Although they can manifest with ameliorated phenotype or manifest if skewed inactivation, etc., we intend that this is implicit in the term as characteristic of many sex-linked disorders and do not anticipate that an additional qualifier term is needed to communicate this, unless the heterozygous phenotype is sufficiently distinct as to be classified as a different disease entity. It is also implicit that monoallelic variants in females with chromosomal anomalies (eg, 45,X) and biallelic variants in females would also meet the allelic requirement. A mode of inheritance that is observed for recessive traits related to a gene encoded on the X chromosome. In the context of medical genetics, X-linked recessive disorders manifest in males (who have one copy of the X chromosome and are thus hemizygotes), but generally not in female heterozygotes who have one mutant and one normal allele. UMLS:C1845977 monoallelic_X_hemizygous X-linked recessive HP:0001419