Albinism

Question 1

What is albinism?

Answer 1

represents a heterogenous group of inherited pigmentary disorders
- characterised by generalised reduction of ocular, cutaneous and hair pigmentation from birth.

Question 2

Types of albinism?

Answer 2

4 types of Oculocutaneous albinism (OCA 1-4)

Question 3

Describe OCA 1?

Answer 3

OCA 1A - total absence of tyrosinase enzyme
> total lack of melanin production
OCA 1B - low level or very defective tyrosinase (<5-10% of normal)
> greatly diminished melanin production

Question 4

OCA 2?

Answer 4

mutation of p-gene
> Lack of essential acidic environment in melanosomes for melanogenesis.

Question 5

OCA 3?

Answer 5

mutation of tyrosinase associated protein 1 gene
> loss of factor that stabilizes tyrosinase in melanosomes

Question 6

OCA 4?

Answer 6

mutation of membrane associated transporter protein
> dysfunctional melanosomal membrane
`

Question 7

Desvribe OCA 1?

Answer 7

results from total absence (OCA1A) or very low levels (OCA1B) of melanin pigment.
1. In OCA 1A (tyrosine negative OCA) there is absolute lack of tyrosinase activity.
2. OCA 1B (tyrosine positive OCA) has extremely reduced tyrosinase activity.
- Consequently, OCA 1B may develop some pigmentation as they grow older.

Question 8

OCA1A clinical features?

Answer 8

1. At birth: white hair, pinkish skin colour, blue grey iris and prominent red reflex.
2. As they grow: no change in pigment, though hair may turn yellow due to UV keratin denaturation. No lentigines development.
3. Associated features: photophobia, nystagmus, foveal hypoplasia, strabismus,

Question 9

OCA1B clinical features?

Answer 9

1. At birth: white hair, pinkish skin colour, blue grey iris and prominent red reflex
2. As they grow older: hair may turn light yellow or golden blond, before becoming dark blond or dark brown in adulthood.
   - Skin may develop lentigines and nevi during first few decades
3. Associated Features: photophobia, nystagmus, foveal hypoplasia, strabismus,

Question 10

OCA2 clinical features?

Answer 10

1. At Birth: may have some hair pigment; white, light/golden blond or brown. Pigmented birth marks may be present.
2. As they grow older: increased pigmentation of the skin (freckles), hair (brown) and eyes (blue to light brown) tend to develop
3. Associated factors: photophobia, nystagmus, foveal hypoplasia, strabismus - but less severe

Question 11

Complications of OCA?

Answer 11

Extreme sensitivity to UVR leading to
1. Actinic keratoses
2. Basal cell carcinoma
3. SCC

Question 12

Medical problems caused by lack of melanin?

Answer 12

1. Sun damage of the skin leading to painful red skin (sun burn)
2. Damaged cells may later become cancer cells
3. Eyes
   - Poor vision
   - Photophobia: severe discomfort when exposed to light, which they try to avoid

Question 13

Social problems?

Answer 13

1. PWA called derogatory terms: mzungu, napweri
2. Not considered humans
3. Brutal attacks and killings
4. Exclusion from getting social rights: jobs, education, social services
5. Women divorced, abandoned when given birth to a child with albinism

Question 14

Diagnosis?

Answer 14

• Made clinically based on skin and ocular features.
• Differentiating types not always possible clinically, so molecular analysis only accurate way towards specific diagnosis.
• Rarely necessary in daily clinic al practice

Question 15

Histopathology?

Answer 15

1. Normal melanocytes but with no melanin staining.
2. Keratinocytes and other cells normal.

Question 16

Management?

Answer 16

1. No cure for albinism.
2. Major enemies of PWA
   Hostility of uninformed society
   Hostility of tropical sun

Question 17

Education?

Answer 17

1. parents, relatives, affected patients, society at large
2. help reduce stigma, wrong traditional beliefs and violence and brutality towards and against PWA.
3. Formal education for all children, since albinism does not lower intelligence , but vision
   - warrants additional support and patience at school.

Question 18

Protecting against the hostility of the tropical sun?

Answer 18

1. Sun avoidance: in-door jobs; staying in doors where possible during ‘peak hrs’ (10-16hrs).
2. Sun protection: sun protective wear (long sleeved shirts, scarf, long trousers/skirts, wide-brimmed hats, sun glasses).
3. Correct and regular use of sunscreens:
   daily during peak hrs, apply 30 mins before going into the sun, repeat after 20 mins, then every 2hrs thereafter or soon after sweating, getting wet.
   especially in sun exposed areas

Question 19

Other kinds of management?

Answer 19

1. Magnifiers to aid schoolchildren with reading.
2. Sitting affected school children ‘at the front.’
3. Treatment of AKs, Cancers: cryo-freezing, surgery hence need for regular follow up in skin clinic

Question 20

Myths that are to be corrected in albinism?

Answer 20

1. Albinism is not a curse
2. The mother of a child with albinism did not sleep with a white man
3. It is not because the woman looked at a person with albinism while pregnant
4. Persons with albinism are not ghosts
5. They do die as all human beings do, not just vanishing into thin air
6. They can eat and drink anything like everyone
7. Sexually abusing them cannot cure AIDS
8. Their body parts have nothing special to enrich a person.
9. Both partners blessed with a child with albinism are its rightful parents legally and genetically, The parents themselves need not always be persons with albinism. The child deserves love from the parents and family unconditionally!!
10. Beside the skin colour and the associated medical problems, nothing distinguishes persons with albinism from those with pigment