Question

Chapter 9: The discussion topic for this week is very interesting, as it is likely that everyone at least knows someone who has some type of genetic disorder or has heard about a disorder that they wanted to understand more fully. You should look into a specific disorder and provide more information about it from any angle you like.

Please be sure to include some information that pertains to the chapter (like the inheritance pattern--that is, whether it is autosomal dominant or recessive or sex-linked or whatever).

You should look into a specific disorder and provide more information about it from any angle you like.

Please be sure to include some information that pertains to the chapter (like the inheritance pattern...this is what you need to talk about...

***I absolutely need in text citations and the ending reference citations...*****

Answer 1

Kindly see the following pedigree, it is of the X-linked recessive disorder: Haemophilia-In haemophilia, certain clotting factors are absent in the blood because of which blood does not clot.

How to conclude that the trait is recessive?

• If the trait is skipping generations.
• If the affected children are borne to the unaffected parents.

How to conclude that it is autosomal or sex-linked:

• If the affected individuals have same number of females and males then the trait is autosomal.
• If the affected males are more than the females then the trait is X-linked.

Sex- linked genes are those genes which are present on the sex chromosomes, thus beside controlling sex they also help in inheritance of certain traits. The traits which are controlled by such genes are known as sex-linked traits.

In the above pedigree, the affected individuals are skipping generations, unaffected parents have affected child, and males are more affected than the females, thus the trait is X-linked.

As blood does not clot thus a mere small cut could be life-threatening in this disorder. This trait is present in the Royal family of England.

References :

'What is Haemophilia?". NHLBI. July 13, 2013. Archived from the original on October 4,2016. Retrieved September 8, 2016.