BRAINCAKESex-Linked Diseases
Sex-linked diseases are caused by faulty alleles of genes on the sex chromosomes. Most are X-linked recessive. Well-known examples include haemophilia, red-green colour blindness and Duchenne muscular dystrophy.
Because males have only one X chromosome, a male with one recessive allele (XaY) is affected. A female needs two recessive alleles (XaXa) to be affected; a female with one (XAXa) is an unaffected carrier.
Typical features of X-linked recessive inheritance:
Sign in free to see the rest of this lesson, the R.E.C.I.P.E. recall steps and the quiz
BrainCake is free. Make an account in seconds and pick up where this page stops.
Key terms in this lesson
- carrier
- A heterozygous individual who carries a recessive allele for a condition without showing it themselves.
More in Genetic Information
- Gene Linkage
- Identifying Linked Genes
- Chromosome Mapping
- Sex-Linkage
- Pedigree Diagrams
- The Albino Trait
- Red-Green Colour Blindness
- Haemophilia
All 30 lessons in Genetic Information · All Edexcel A-level Biology topics