Xeroderma pigmentosum (XP) is an autosomal recessive condition ch...

Question

Xeroderma pigmentosum (XP) is an autosomal recessive condition characterized by moderate to severe sensitivity to ultraviolet (UV) light. Patients develop multiple skin lesions on UV-exposed skin, and skin cancers often develop as a result. XP is caused by deficient repair of DNA damage from UV exposure.

Many genes are known to be involved in repair of UV-induced DNA damage, and several of these genes are implicated in XP. What genetic phenomenon is illustrated by XP?

Accepted Answer

Hello, everyone and welcome to today's video. So, hemophilia is a bleeding disorder that impairs their body's ability to form blood clots. Hemophilia is caused by mutations in genes that provide instructions for making proteins involved in blood clotting, including the F eight gene and the F nine gene. It is more commonly seen in males than females, which is a type of genetic inheritance illustrated in this example as answer choice A we have autosomal dominant as answer choice B, we have autosomal recessive as answer choice C we have excellent dominant and as answer choice D we have X linked recessive. So the key point in order to solve this problem is going to be this thing that we highlighted here, which is more commonly seen in males than females. So as it turns out the F eight and the F nine genes are both located in the X chromosome. So this disease is going to be X linked. Now, when males are more commonly affected than females, this is going to be because males have only one copy of the X chromosome. So if males receive only one copy of hemophilia, they will display the trait and the reason why females are seen as less or just in a lesser frequency is because we would need two copies of this gene in order for them to show in females. So when we need only one copy in males and two copies in females, for genes to for a certain trait to show, we say that this is going to be an X linked recessive trait, which is going to be represented by answer choice D X linked recessive. I really hope this video helped you and I hope to see you on the next one.

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