Genetic Retinal Disease

Question 1

What is retinitis pigmentosa caused by

Answer 1

Loss of rod photoreceptors

Question 2

Presentation of retinitis pigmentosa

Answer 2

Night time blindness
Progressive visual loss

Question 3

How is retinitis pigmentosa inherited

Answer 3

Autosomal domination
Recessive
X linked

Question 4

What is most commonest mutation in retinitis pigmentosa

Answer 4

RHO gene on chromosome 3

Question 5

What does rho gene code for

Answer 5

Rhodopsin

Question 6

Presentation of retinitis pigmentosa

Answer 6

Tunnel vision
Nyctalopia - night blindness
Decrease visual acuity
Bilateral involvement

Question 7

Fundoscopy of retinitis pigmentosa

Answer 7

Retinal Pigmentary changes e.g. bony spicules
Waxy disc pallor
Arteriolar attenuation

Question 8

Management of retinitis pigmentosa

Answer 8

None as such
Vitamin A
Gene therapy

Question 9

Inheritance pattern of choroideremia

Answer 9

X linked

Question 10

What is choroideremia

Answer 10

Widespread progressive degeneration of the photoreceptors, RPE and choriocapillaris

Complete loss of choroid which exposes the underlying white sclera

Question 11

Who is most likely to be affected if it is x linked

Answer 11

Males

Question 12

What gene is affected in choroideremia

Answer 12

CHM gene encoding the REP-1 protein

Question 13

Fundosocpic finding in choroideremia

Answer 13

Widespread pigment clumping

Question 14

What is leber congenital amaurosis

Answer 14

Cause profound visual loss by age of 1

Question 15

Inheritance of leber congenital amaurosis

Answer 15

Autosomal recessive

Question 16

Inheritance of Stargardt disease

Answer 16

Autosomal recessive

Question 17

Mutation in stargardt disease

Answer 17

ABCA4 in short arm of chromosome 1

Question 18

Features of stargardt disease

Answer 18

Bilateral central vision loss
Reading difficulty in teenagers
Color vision abnormalities
Photophobia
Slow dark adaption

Question 19

Fundoscopy of stargardt disease

Answer 19

Bulls eye maculopathy
Beaten bronze macula
Deposited lipofuscin

Question 20

Inheritance of best disease

Answer 20

Autosomal dominant

Question 21

What mutation causes best disease

Answer 21

BEST1 on long arm of chromosome 11

Question 22

Presentation of best disease

Answer 22

Slow decline in visual acuity
Central scotoma
Metamorphopsia

Question 23

Fundoscopy of best disease

Answer 23

Bilateral yellow egg yolk appearance of the macula

Question 24

What type of inheritance of ocular albinism

Answer 24

X linked

Question 25

What mutation is in ocular albinism

Answer 25

GPR143

Question 26

Features of ocular albinism

Answer 26

Reduced visual acuity
Photophobia
Nystagmus
Strabismus
Refractive errors

Question 27

Management of ocular albinism

Answer 27

Reduce sun exposure
Sunglasses
treat refractive errors