Question

Name any two autosome linked recessive disorders.

Hint:

Look for disorders carried on a non sex chromosome that need two copies of the faulty gene.

Answer 1

Step 1: Understand what 'autosome linked recessive' means.
An autosome is any chromosome other than the X and Y sex chromosomes. A recessive disorder only shows up when a person inherits the faulty allele from both parents (is homozygous recessive).

Step 2: Give the first example, sickle cell anaemia.
Sickle cell anaemia is caused by a mutated allele of the gene for the beta chain of haemoglobin, carried on an autosome. A person needs the mutant allele from both parents to show the disease.

Step 3: Give the second example, phenylketonuria.
Phenylketonuria is caused by a recessive allele, also on an autosome, that fails to make the enzyme needed to break down the amino acid phenylalanine, and it too only appears when both copies of the gene are faulty.

Final Answer:
Sickle cell anaemia and phenylketonuria are two autosome linked recessive disorders.