Diseases - Part 2

Question 1

Hemochromatosis is a mutation in what gene?

Answer 1

HFE gene

Question 2

Hemochromatosis is a mutation in what allele?

Answer 2

C282Y

Question 3

What are other known mutations of the HFE gene?

Answer 3

• H63D

- S65C

Question 4

In sickle cell anemia, what are the two possible mutations in the B-globulin gene?

Answer 4

• S mutation

- C mutation

Question 5

Hemophilia A (deficiency)

Answer 5

deficiency of clotting factor VIII

Question 6

Hemophilia A (causes)

Answer 6

Most severe mutations in factor VIII gene involve inversions of an intron sequence.

Question 7

Incontinentia pigmenti

Answer 7

– Males with the disorder typically die in utero

– Females are less severely affected than males

– Manifests as rashes & blisters in early life

– Later, patches of hyperpigmentation, ‘Marble cake appearance’ of skin

– Mental retardation (in some patients)

– Retinal detachment (in some patients)

Question 8

Rett syndrome

Answer 8

• Rett syndrome affects females more often than males
• Males with the mutant gene on X- chromosome, usually die in utero or soon after birth
• The mom in the pedigree does not have the manifestations of the disease – may be due to the phenomenon of skewed X chromosome inactivation or the disorder may be due to a germline mutation in the mother