In a family, mother is normal while father has a genetic disease. All their daughters are carriers and sons are normal, what is the pattern of inheritance of disease?
a. X-linked recessive(Ref: Nelson's 20/e p 595, Ghai 8/e p 640)In a X-linked recessive disease; affected male transmits the disorder to all his daughters (carriers)Sons get their X chromosome from their mother & not from their fatherHence sons of a diseased father are unaffected in X-linked diseasesIn an X-linked dominant disorder all the daughters of an affected father would be diseased and not carriers.
X-linked recessive
X-linked dominant
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Genetics And Genetic Disorders