Albinism is a type of inherited disorder in which there is complete or partial lack of pigment melanin in skin, hair and eyes. This condition occurs due to defect or complete lack of the enzyme tyrosinase, an enzyme responsible for production of melanin. Albinism is a congenital disorder and occurs due to inheritance of defective recessive genes. This condition is known to affect all the vertebrates including human beings.
Albinism leads to various visual problems like increased sensitivity to light (photophobia), involuntary rhythmic eye movements (nystagmus) etc. Deficiency of melanin pigment in the skin leads to increased sensitivity to sun rays and increased chance of suffering from skin cancer. There is no cure for albinism however eye problems can be successfully managed by various interventions. Albinism does not interfere with intellectual development of an affected person however due to social taboo these people often feels isolated
In humans albinism can take two different forms namely oculocutaneous characterized by involvement of eyes, hair and skin and ocular characterized by involvement of eyes only. In people suffering from oculocutaneous variety skin complexion appears to be very pale or completely white whereas in ocular variety the only presenting symptom is pale blue pupil, thus requiring genetic test to establish the diagnosis in this variety.
Sometimes the pale skin in people with oculocutaneous variety may change over time following starting of melanin production although in others skin color remains constant throughout their lives. Following sun exposure certain changes in the skin may appear like freckles, moles even tanning.
Hair color is also affected and may range from white to brown, sometimes reddish even yellowish hair is also seen. Like skin color hair color may also change with age. Color of the eyes may range from brown to pale blue and also tend to change with age. In some of the affected person eyes may appear red because of complete lack of pigment in the iris and subsequent failure of the irises to block light passing through them.
Eye functions are affected in both the varieties of albinism. These are fast uncontrollable to and fro or circular movement of the eyeballs (nystagmus), extreme degree of near sightedness or far sightedness, increased sensitivity to light (photophobia), astigmatism due to irregular shape of cornea, optic nerve hypoplasia due to poor development of the said nerve etc.
Albinism may lead to number of complications like increased tendency to suffer from sun burn and skin cancer. Apart from physical complications albinism often leads to number social problems like social isolation leading to poor self esteem and depression.
Albinism occurs following inheritance of mutated genes responsible for melanin production. In order to suffer from albinism the affected person must inherit two copies of defective genes from both the parents and inheritance of only one copy does not cause the disease.
Other than two principal forms of albinism oculocutaneous and ocular, there are two rare types of albinism may occur. These are Hermansky-Pudlak syndrome characterized by symptoms of oculocutaneous albinism along with lung, bowel disorder and increased bleeding tendency and Chediak-Higashi syndrome where the affect person suffer from immunological defects along with oculocutaneous symptoms.
There is no cure for albinism however special visual aids to surgical interventions are available to treat ocular symptoms. Regular check up is required to rule out skin lesions that can lead to skin cancer. Special measures are required to prevent complications associated with Hermansky-Pudlak syndrome and Chediak-Higashi syndrome.