Albinism

Oculocutaneous albinism (OCA) affects the skin, hair and eyes and is the most common type of the disease. Ocular albinism (OA) is less common and only affects the eyes. They are further divided into subtypes - here is a quick look at them: 

OCA1: This is the most common type and occurs because of a mutation in the enzyme tyrosinase. Tyrosinase is needed to convert amino acids into pigments. OCA1 is further divided into:

• OCA1A in which the enzyme is completely inactive and no melanin is produced. People with this variation are extremely pale and have white hair.
• OCA1B in which the enzyme can perform a limited amount of its functions. Some melanin is produced and people with this disorder will have slightly darker hair (no darker than light brown though) and slightly more pigmented skin.

OCA2: There is a mutation in OCA2 gene, which encodes the P protein that is one of cogs involved in the pigmentation process. People with this type are also able to produce slight amounts of melanin. This type is more common in the African continent as well. 

OCA3: This is a rare type of albinism that is more prevalent in those with darker skin. It is caused by a mutation in the TYRP1 gene which also plays a role in developing the building blocks of pigmentation. Pigmentation does occur in this subtype; the hair is of a reddish colour, and the eyes and skin are brown. 

OCA4: In this subtype, tyrosinase function is impaired because of a mutation in the protein SLC45A2. Some melanin production is possible; it manifests similarly to OCA2. 

OCA5-7: These are obscure variations of the disease and have not yet been extensively documented. They occur because of other variations along the formation or distribution of melanin across the body. 

Ocular albinism (OA): OA affects only the eyes, and mostly follows an X-linked inheritance pattern. Unlike OCA, OA is much more common in men since they only need one copy of the mutated gene to get the disease. If the mother has X-linked albinism, there is a 50% chance the son will inherit the disease. OA is caused by a mutation in the GPR 143 gene that plays a signalling role in the pigmentation of the eye.

(Read more about eye disorders.)

Other than this, there are other obscure metabolic disorders linked with albinism. These include Hermansky-Pudlak syndrome and Chediak-Higashi syndrome. There are bleeding issues with the former and neurological symptoms with the latter. These forms of the disease are more serious and complications associated with them often lead to shorter average lifespans.

Symptoms of albinism vary depending on the type of the condition, but it largely manifests in the following ways: 

• Extremely pale, light skin 
• White hair, eyebrows and eyelashes (some may have brown or red hair)
• Light eyes that appear red in certain circumstances
• Large freckles and moles
• Nystagmus: An involuntary and rapid side-to-side movement of the eyes 
• Squint or strabismus: Both eyes look in different directions and are not in synchronization with each other.
• Repeated head bobbing and head movements
• Refractive errors such as far sightedness and short sightedness 
• Photophobia, or sensitivity to light 

There are many other ocular complications including being legally or permanently blind, poor depth perception, optic nerve, retinal and iris problems. These can lead to problems with learning, operating machinery and vehicles if they are not addressed in a timely manner. 

(Read more: Eye disorders)

Further, since the skin is more susceptible to disease and wear and tear, precautions need to be taken to protect it from overexposure to sunlight. Those with albinism are at an elevated risk of squamous cell and basal cell carcinoma.

(Read more: Skin cancer.)

Genetic mutations that influence the functioning of melanin lead to the development of albinism. Melanocytes, which are the cells responsible for the pigmentation of the eyes, hair and skin cannot function properly and are not able to transfer pigments to keratinocytes which are the cells that make up the majority of the epidermis, the visible part of the skin. 

In the most common type of OCA albinism, there is a mutation in the gene TYR that codes for the enzyme tyrosinase. Tyrosinase is used to convert amino acids into different pigments-- the mutation disrupts this process. 

Albinism is a genetic disorder, and it can occur in those with close family history. As mentioned above, albinism is most commonly inherited in an autosomal recessive pattern; both parents must carry mutated copies of the genes.

OCA albinism is easy to detect at birth. On observation, the baby will have less pigmentation when compared to its family. Genetic testing is required for an accurate diagnosis - it will reveal what type of mutation(s) caused the disorder, though lifelong treatment will likely remain unchanged. An ophthalmologist will be consulted to conduct an electroretinography to check for various vision problems and developmental issues with the retina. 

Skin biopsies and hair bulb extractions can also be conducted to check for melanin levels.

(Read more about biopsy.)

There is unfortunately no cure for albinism yet. However, clinical trials are looking into the scope of gene therapy to lead to some sort of a cure. For now, treatment is focused on managing symptoms that are caused by the lack of melanin activity. 

For those with eye and vision problems, eye tests will need to be conducted routinely to check for signs of deterioration. Glasses and contacts are prescribed to correct for short or long sightedness. Several low vision aids such as magnifying lenses, magnified text, large screens, reading aids or text to speech technology can be utilized to help with vision problems. Some practical steps such as setting close to the front in the classroom are helpful as well. Surgery for symptoms such as nystagmus may be recommended to reduce eye fluttering, but this is rare and often not needed. 

(Learn more: How to improve eyesight.)

Skin care is extremely important as well and is required to prevent various skin cancers and early aging. Sunscreens with an SPF of at least 30 should be used when stepping out, and it is highly advised to avoid being out in the sun when it is as its harshest. Frequent physical checkups will also be recommended to check for any growths that may be malignant. 

Those with albinism are likely to have vision problems they suffer from throughout life, but the social dimensions of the disorder is perhaps what causes the most grief. People with albinism may be singled out for their appearance and bullied. Their professional lives can suffer due to learning problems brought on by poor vision. Counselling and support groups, therefore, also play a key role in the management of the disorder.