X-linked recessive inheritance

X-linked recessive inheritance is a mode of inheritance in which a mutation in a gene on the X chromosome causes the phenotype to be expressed in males (who are necessarily hemizygous for the gene mutation because they have one X and one Y chromosome) and in females who are homozygous for the gene mutation.

Genetics

X-linked recessive inheritance works differently in males and females. Males have one X chromosome and one Y chromosome (XY). If a gene on the X chromosome is faulty, they will have the condition because they do not have another X chromosome with a working copy of the gene. Females have two X chromosomes (XX). If a gene on one of their X chromosomes is faulty, they may not have the condition because they have another X chromosome with a working copy of the gene. This is called being a carrier.

Examples

Some examples of diseases with X-linked recessive inheritance include Hemophilia A, Duchenne muscular dystrophy, and Color blindness.

See also

• Genetic disorder
• X-linked dominant inheritance
• Y-linked inheritance

References

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