Pedigree Question

[virajpatel]

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Can someone explain why this is recessive? It does not skip any generations

 

[Ari Rezaei]

Check out the first and third lineages, it does skip generations 🙂

 

[Piepiesuperpie]

Gen 3-2 and gen 3-7 have the disease but no diseased parents. This means that the disease can't be dominant (test it out for these 2 if you don't believe me).

 

[aspiringmd1015]

very easy, its x linked recessive. the entire second generation was "skipped" but the daughters still inherited a recessive x gene so are "carriers" and then passed it onto their sons, and as their sons only have one x gene being hemizygous, they are inflicted with the disease no matter what and which is why their boxes are shaded.