Question

What evidence could you collect to confirm that the mutation identified in Sam’s DNA causes symptoms of RP?

Answer 1

Retinitis pigmentosa (RP) this is a genetic disorder that is seen causing breakdown and loss of cells in the retina this leads to sensitivity to light, tissue lines in the back of the eye.

Signs and symptoms includes

a. Tunnel vision

b. Night blindness

c. Photophobia

Causes of the disease

a. Autosomal recessive RP – in this cells DNA fails to copy similar gene when replicating leading to mutation

b. Autosomal dormant – parents copy of defective gene gets replicated and causing disease

c. X – linked RP – a mother being a carrier and passes the defective gene to children especially male child would suffer whereas female child shall become carrier

Diagnosis

- Ophthalmoscope – dark spots in retina may indicate the defect

- Visual field test – test of side vision / peripheral vision diminished

- Electroretinogram - a film of gold foil or a special contact lens is placed on the eye and then flashes light to the eye the response of retina is recorded

- Genetic test – the blood sample assess the type of DNA and type of defect present in the person