Albinism

Albinism, also known as achromia, achromasia, or achromatosis, is a congenital condition characterised by the partial or complete absence of pigment in the skin, hair, and eyes. This lack of melanin results in increased susceptibility to sunburn and skin cancers. Albinism is associated with several vision defects, such as photophobia, nystagmus, and amblyopia. In rare cases, it may be linked to immune deficiencies, notably in Chédiak–Higashi syndrome.

Overview

Albinism, also known as achromia, achromasia, or achromatosis, is a congenital condition characterised by the partial or complete absence of pigment in the skin, hair, and eyes. This lack of melanin results in increased susceptibility to sunburn and skin cancers. Albinism is associated with several vision defects, such as photophobia, nystagmus, and amblyopia. In rare cases, it may be linked to immune deficiencies, notably in Chédiak–Higashi syndrome.

Signs and Symptoms

There are two principal types of albinism: oculocutaneous, affecting the eyes, skin, and hair, and ocular, affecting the eyes only. Individuals with albinism entirely lack melanin, making their skin more vulnerable to ultraviolet radiation. The iris may vary in colour but lacks sufficient pigment to block light effectively, leading to increased visibility of the retina through the iris and a higher likelihood of "red eye" in photographs.

Visual problems in albinism include:

• Misrouting of optic nerve fibres
• Photophobia and decreased visual acuity due to light scattering
• Foveal hypoplasia and potential light-induced retinal damage

Common eye conditions include:

• Nystagmus: irregular rapid eye movements
• Amblyopia: decreased acuity due to poor transmission to the brain
• Optic nerve hypoplasia: underdevelopment of the optic nerve

Genetics

Oculocutaneous albinism results from recessive gene alleles inherited from both parents. Mutations in genes such as OCA1 and OCA2 are common causes. There are also rare forms inherited from one parent, and some genetic mutations linked to albinism increase skin cancer risk. Albinism occurs equally in both sexes, except ocular albinism, which is more frequent in males due to X-linked inheritance.

Diagnosis

Diagnosis involves a careful examination of the eyes, skin, and hair, with genetic testing available to confirm albinism and identify specific types. Albinism can be part of several syndromes, including Hermansky-Pudlak syndrome, Waardenburg syndrome, and others.

Management

Albinism management focuses on lifestyle adjustments to prevent sunburn and regular dermatological checks. Visual rehabilitation is essential, with options like surgery to correct strabismus and nystagmus-damping procedures. Tinted glasses, low vision aids, and magnifiers can help with vision issues. Sunglasses to filter ultraviolet light and bioptics for driving are also beneficial.

Epidemiology

Albinism affects people of all ethnic backgrounds, with a global frequency of approximately one in 17,000. It is most prevalent in sub-Saharan Africa, with some regions reporting rates as high as one in 1,000. Certain isolated populations and ethnic groups exhibit higher susceptibility due to genetic factors.

Society and Culture

Albinism carries significant social and cultural implications. Some Native American and South Pacific cultures have revered albinos, attributing divine origins to them. Conversely, in many African countries, albinos face severe persecution, including witchcraft-related killings and harmful myths, such as the belief that sex with an albino woman cures HIV.

International Albinism Awareness Day

International Albinism Awareness Day is observed on June 13, established by the United Nations to raise awareness and combat discrimination against people with albinism. The UN also appointed the first Independent Expert on the enjoyment of human rights by persons with albinism to further this cause.

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Self-assessment MCQs (single best answer)

What is albinism also known as?

Albinism increases susceptibility to which of the following?

Which type of albinism affects the eyes, skin, and hair?

Which eye condition is characterised by irregular rapid eye movements in individuals with albinism?

What is a common genetic cause of oculocutaneous albinism?

What is the frequency of albinism globally?

Which syndrome associated with albinism involves immune deficiencies?

Albinism is most prevalent in which region?

What is the primary focus of managing albinism?

When is International Albinism Awareness Day observed?