A couple has one daughter with Tay-Sachs disease and three other unaffected children. Neither the mother, nor father, nor any of the biological grandparents of the affected daughter have had the disease. Tay-Sachs disease most likely demonstrates what type of inheritance? Select one: a). autosomal recessive. b). X-linked dominant. c). autosomal dominant. d). X-linked recessive
I think it is b but i am not sure please help me out. Thank you so much and have a great day
5 years ago
Answered By Gregory S
When answering inheritance questions it's important to remember a few key things. When it comes to X linked it's very rare to affect women because they get two copies and if one is broken or damaged they will just use the other. (women are XX men are XY so x linked will affect men more often) with dominant traits they just need one copy to show the trait, such as brown eyes. So since it's a female affected it's pretty safe to rule out XLinked. And only one child of 4 we can rule out mitochondrial and since neither parent or grandparents are affected we can rule out dominance inheritance leaving us only autosomal recessive as the answer.