Albinism

Albinism is a genetic disorder characterized by the partial or complete absence of pigment (melanin) in the skin, hair, and eyes. It results from a group of inherited genetic mutations that affect the production or distribution of melanin.

Etiology and Pathophysiology

Albinism is primarily inherited in an autosomal recessive manner, meaning that both parents must carry a mutated gene for their child to be affected. These genes are involved in the production of melanin or the enzymes required for its synthesis. The specific genes involved vary depending on the type of albinism. The most common types include oculocutaneous albinism (OCA) and ocular albinism (OA).

In OCA, the melanin production is impaired in the skin, hair, and eyes. Mutations in genes such as TYR, OCA2, TYRP1, and SLC45A2 are commonly associated with different types of OCA. In contrast, OA primarily affects the eyes, and mutations in the GPR143 gene are usually responsible.

Distinctive Features and Clinical Presentation

The hallmark dermatological feature of albinism is the absence or reduction of melanin pigment in the skin. This results in a strikingly light complexion, characterized by a pale or milky-white appearance. The skin is highly susceptible to sunburn and damage from ultraviolet (UV) radiation due to the lack of protective melanin. Therefore, individuals with albinism must take extra precautions to protect their skin from sun exposure.

The lack of melanin in the eyes can result in various eye abnormalities, such as nystagmus (involuntary eye movements), strabismus (misalignment of the eyes), and photophobia (sensitivity to light). Reduced pigmentation in the iris may cause the irises to appear light blue, green, or gray.

In addition to photosensitivity, individuals with albinism may experience other dermatological manifestations. These can include freckle-like macules, which are small, well-defined, light brown spots that may appear on sun-exposed areas over time. The macules are not true freckles but rather an accumulation of melanin precursor molecules due to impaired melanin production.

Diagnosis

The diagnosis of albinism is typically made based on clinical examination, family history, and specialized tests to assess visual function. Genetic testing may be performed to confirm the specific type of albinism and identify the responsible gene mutations.

Management

Management of albinism primarily focuses on minimizing the complications associated with the condition. One of the significant complications associated with albinism is an increased risk of developing skin cancers, including melanoma. The absence of melanin, which acts as a natural protective barrier against UV radiation, makes the skin more vulnerable to the harmful effects of the sun. Therefore, individuals with albinism must adopt strict sun protection measures to minimize the risk of skin cancers. These measures include using broad-spectrum sunscreen with a high sun protection factor (SPF), wearing protective clothing that covers the skin, seeking shade during peak sun hours, and regularly examining the skin for any suspicious lesions.

Regular dermatological examinations are essential for early detection of skin cancers in individuals with albinism. Dermatologists can perform thorough skin examinations and educate patients about self-examination techniques. Any suspicious skin lesions should be promptly evaluated and, if necessary, biopsied for further assessment

Visual aids, such as prescription glasses, contact lenses, or low-vision aids, can help improve visual acuity and alleviate the symptoms of nystagmus and strabismus. Regular eye exams are crucial for monitoring and managing any ophthalmic complications.

Psychological support and counseling are essential for individuals with albinism, especially during childhood and adolescence, as they may experience social and psychological challenges due to their appearance and visual impairments. Educating family members, peers, and educators about albinism can foster understanding and support.

Written by:

Deemah AlHuraish, Medical Student.

References:

DermNet 

Medscape