Albinism - Classification, Causes, Symptoms, Diagnosis, and Treatment

Introduction:

Melanin is a type of pigment that gives color to the hair, eyes, skin, and nails in both humans and animals. There are specialized cells in the skin called melanocytes, which help produce melanin in the body. Everyone has the same number of melanocytes, but melanin production varies. Some people produce more melanin than others. The amount of melanin production depends on the genes. For people who produce little melanin, the skin, hair, and the eye's iris can be lighter in color, and for those with more melanin production, the skin can be darker.

What Is Albinism?

Albinism is typically an inherited disorder that is characterized by minimal or no production of the pigment melanin. This condition is also known as achromasia. Melanin also protects the skin from harmful UV (ultraviolet) rays. Hence, people with albinism are more sensitive to the sun and are more likely to develop skin cancer as early as teenage ages. Albinism is associated with vision problems because melanin also has a role in the development of optic nerves. In a study, it was estimated that one in 70 people carry the gene mutation that is associated with albinism.

What Are the Various Types of Albinism?

Albinism types are categorized based on inheritance patterns and the specific gene affected.

• Oculocutaneous albinism (OCA), the most prevalent type, is inherited when an individual receives two copies of a mutated gene — one from each parent. This mode of inheritance is termed autosomal recessive. OCA results from alterations in one of eight genes, designated OCA1 to OCA8. It leads to reduced pigment in the skin, hair, and eyes and vision impairments. The degree of pigmentation varies among the different types, and there is also variation in the resulting skin, hair, and eye colors within each type.

• Ocular albinism primarily affects the eyes, causing vision issues. The predominant form of ocular albinism is type 1, inherited through a gene mutation on the X chromosome. X-linked ocular albinism can be transmitted from a mother who carries one altered X gene to her son, a pattern known as X-linked recessive inheritance. Ocular albinism occurs exclusively in males and is significantly less common than OCA.

• Albinism associated with rare hereditary syndromes may also occur. For instance, Hermansky-Pudlak syndrome encompasses a form of OCA alongside bleeding and bruising disorders, as well as pulmonary and gastrointestinal complications. Similarly, Chediak-Higashi syndrome involves a type of OCA alongside immune issues leading to recurrent infections, neurological and hematological disorders, and other serious conditions.

Does Albinism Have a Genetic Basis?

Yes, albinism is hereditary, meaning it is passed down through families. Individuals are born with albinism when they inherit the gene from their parents. For oculocutaneous albinism to occur, a child must receive the albinism gene from both parents. There is a one in four chance that the child will inherit albinism. If only one parent carries the albinism gene, the child will not have oculocutaneous albinism. However, they will have a 50 percent chance of being gene carriers.

What Are the Common Causes of Albinism?

Albinism is typically an inherited condition that has been present since birth. The chances of a child developing albinism are high when both parents have albinism or if both parents carry the gene that causes albinism. The primary cause of albinism is a gene defect that contributes to melanin production. This defect in the gene can cause either reduced melanin production or the absence of melanin production. For many types of albinism, both parents must carry the gene for the child to develop the disorder. In contrast, in most cases, people develop albinism even when the parents are just carriers of the gene and do not have any symptoms.

What Are the Risk Factors for Albinism?

Risk factors depend on whether one or both parents carry the affected gene. Different types of albinism follow different inheritance patterns.

What Are the Symptoms of Albinism?

Albinism manifests through various signs and symptoms affecting the skin, eyes, and hair.The hallmark signs of albinism are light-colored skin and white skin. The skin and hair color ranges from white to brown. They can also have patches of the skin that have an absence of color. Symptoms of albinism involving the eyes include:

• The eyebrows and eyelashes are often pale, and the eyes range from light blue to brown. The absence of pigment in the colored part of the eyes gives the iris a translucent color.

• The impairment of vision is one key feature of albinism, as the most dramatic effects of albinism are seen in the eyes.

• Rapid involuntary (back and forth) eye movement (nystagmus).

• Head movements.

• Not being able to keep the eyes directed simultaneously or move in unison (strabismus).

• Being sensitive to light (photophobia).

• Nearsightedness or farsightedness.

• Astigmatism (abnormal inflexibility of the front surface of the eyes or lens) causes blurred vision.

• Optic nerve misrouting (signals transmitted from the retina to the brain do not follow the usual pathways).

• Complete blindness.

How Is Albinism Diagnosed?

Albinism is mostly diagnosed based on the appearance of the skin, hair, and eyes. An electroretinogram is performed to diagnose eye problems related to albinism. Genetic testing is the most accurate way to determine albinism and is most useful for people with a family history of albinism.

Can Albinism Be Treated?

The major aim of treatment is to alleviate the symptoms. The treatment depends on the severity of the disorder. The treatment involves protecting the skin and eyes from exposure to the sun. The treatment includes:

• Regularly use sunscreen with a high SPF (sun protection factor) and try covering up entirely with clothing when exposed to the sun.

• Wear sunglasses to relieve light sensitivity.

• Glasses are prescribed to correct vision problems and other problems related to the eye. Sometimes, eye muscle surgery is suggested to correct abnormal eye movements.

What Are the Complications of Albinism?

Albinism can result in complications involving the skin and eyes, along with social and emotional challenges.

• Eye Complications: Vision issues can affect learning, employment opportunities, and the ability to drive.

• Skin Complications: Individuals with albinism often have highly light-sensitive skin and are prone to sunburn. Extended sun exposure can cause skin damage, resulting in rough and thickened skin. Additionally, the absence of skin pigment elevates the risk of melanoma, a type of skin cancer. Melanoma in individuals with albinism may appear as pink or red growths instead of the usual black or brown, making early detection difficult without regular skin examinations.

• Social and Emotional Challenges: Discrimination is a concern for some individuals with albinism, as reactions from others can have a detrimental effect. They may encounter bullying, teasing, or unwelcome questions about their appearance or visual aid devices. Additionally, feeling different from their families or ethnic groups can lead to a sense of exclusion, potentially causing social isolation, low self-esteem, and stress. It is preferable to use the term "person with albinism" to mitigate the negative impact of other terms.

Conclusion:

Albinism is an inherited condition, so there is no specific way to prevent the condition from occurring, and most types of albinism do not affect a person's life expectancy. However, people with a family history of albinism should consider getting genetic counseling. And since patients with albinism are susceptible to sun damage, they may have to use lifelong precautions for sun protection.