Annabeth and Percy are concerned about having a child with Canavan disease, which causes brain tissue degeneration

Answer:

From the given data :

a.)

Autosomal Recessive:

• This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations.
• The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
• When both parents are found to carry the Canavan gene mutation, there is a one in four (25%) chance with each pregnancy that the resulting child will be affected with Canavan disease.

b.)

• Since the uncle (Mother’s brother) of Annabeth and the sister of Percy are affected, the Annabeth and the Percy are carrier for this disease therefore;

P (child with canavan disease) = P (Annabeth is a carrier) x P (Percy is a carrier)

• Since both parents (Father and Mother) are found to carry the Canavan gene mutation, there is a probability of one in four (25%) with each pregnancy that the resulting child will be affected with Canavan disease.

Therefore ¼ = (2/3 X ½ ) X (2/3) X ¼ = 1/18 = 0.0556 = 5.56 %

2 children are carrier 1 child is affected and 1 child is normal

c.)

P (child with Aa)

= 1/3*2/3* ½ + 2/3*2/3* ½ + 1/3*1/3* ½

= 7/18

= 0.389 = 38.9%

d.)

P (child with Canavan disease) X P (child with hemophilia)

1/18 X P (Annabeth is XHXh) X P (Xh from Annabeth X P ( Y from percy)

=1/18 X ½ X ½ X ½ = 1/44 = 0.0069 = 0.69 %.