Albinism is a disorder of melanin production which is autosomal recessive. Melanin is the pigment responsible for the colour of normal skin which is produced by cells in the skin known as melanocytes. The pigment is also present in iris and retina of eyes and hair. In albinism, the number of melanocytes in the skin are normal but there is a defect in melanin production which leads to white or light coloured skin and eyes. Depending on the type of defect, the pigment may be completely or partially absent.
There are two main types of albinism, oculocutaneous (affecting the skin, hair and eyes) and ocular (affecting only eyes). Another type is Hypomelanosis or Hypomelanism which is a partial lack of the melanin and amelanism or amelanosis which is a complete lack of melanin.
Causes
Oculocutaneous Albinism is a genetically transmitted disorder which is transmitted from parents to children. It is an autosomal recessive disorder. It affects both sexes equally.
Ocular albinism is passed through X-linked inheritance, so it occurs more commonly in males than females because males have only single X chromosome compared to two X-chromosomes in females.
Symptoms
Albinism usually presents at birth but it may go unnoticed in the mild form of the disease in infancy. Ocular symptoms are due to decreased melanin in iris and retina.
Symptoms of albinism are as follows:
- White or pale skin
- Higher tendency to get sunburns
- White coloured hair
- Photosensitivity
- Photophobia
- Refractive errors
- Nystagmus
- Astigmatism
- Amblyopia
Persistent solar exposure presents with solar keratoses and solar elastosis by early adulthood. Due to lack of pigmentation in skin, harmful Ultraviolet (UV) radiation from the sun are not blocked which leads to higher incidence of skin melanoma ( a type of skin cancer) in patients with albinism.
Diagnosis
Diagnosis is mainly based on clinical features of albinism based on signs and symptoms with which patient presents. Genetic testing can confirm the diagnosis but it offers no medical benefits and would burden the patient with extra cost.
Treatment
There is no cure for albinism.
Eye conditions need visual rehabilitation. Surgery on ocular muscles could be recommended to decrease nystagmus, strabismus and refractive errors like astigmatism. Glasses and contact lenses can also be prescribed. Sunglasses can be used to counteract photophobia.
As patients with albinism have higher chances of getting melanoma, the skin has to be protected from harmful UV rays from the sun. This can be achieved with protective clothing, umbrella, cap, avoiding high sun timings like afternoon and using sunscreen lotions on skin. Sunscreen with higher SPF (sun protection factors) is recommended.
Apart from these genetic counselling should be offered to patients who are planning to have a child in future.
