Albinism is a complex of rare inherited disorders that affect melanin synthesis. This pigment is synthesized from an amino acid known as tyrosine, and once synthesized, melanin is stored in melanocytes or in the retinal pigment epithelium.
Affected people, having absence or deficiency of melanin, have a very light color of skin, hair and eyes. But it is that, in addition to causing hypopigmentation (low amount of melanin) or depigmentation (loss of melanin pigment) of the skin, it can also lead to eye problems that affect vision.
Albinism classification
Albinism can be mainly classified into two types: oculocutaneous albinism (OCA) and ocular albinism (OA).
Oculocutaneous albinism (OCA) is the most serious form, since it is the decrease in melanin synthesis, or its absence, mainly in the hair, skin and ocular system. Currently seven types of oculocutaneous albinism are known based on the altered genes that cause the condition, although OCA-1, OCA-2 and OCA-3 are more common than the rest.
It is an autosomal recessive hereditary condition , that is, for a child to suffer from it, both parents must have an affected gene related to albinism, even though neither of them appears to be albino.
This type of albinism may be associated with other hereditary disorders , such as Hermansky-Pudlak syndrome, which is a subtype of OCA associated with blood clotting problems (so they are prone to bleeding and bruising), or Chediak-Higashi syndrome, an inherited disease that manifests with OCA and immune problems.
When we are faced with ocular albinism (OA) , we only see involvement in the eyes, so the skin and hair do have melanin. It can cause nystagmus (rapid and involuntary eye movements), strabismus (eye deviation), macular transparency or photophobia, among other eye and vision problems. This type of albinism is linked to the X chromosome, so the genetic inheritance will affect mostly men since with a single genetic copy they already suffer from the condition, while women need two affected X copies to suffer from albinism, otherwise only They will be carriers.
Signs and symptoms of albinism
People with albinism are easily recognized by their appearance, with light (pink or blue-gray) hair, skin, and eyes. Oculocutaneous albinism is more easily diagnosed than people with solely ocular albinism.
It is common for people with light-colored eyes , a consequence of albinism, to have a decrease in central vision and photophobia (sensitivity to light), in addition to other problems such as strabismus, refractive errors of vision or other vision problems . Visual complications affect learning, lifestyle, employment and the ability to drive.
As for skin conditions , we can find a lack of melanin pigment in the skin, and, as a consequence, photosensitivity of the skin and the ease of appearance of sunburn and skin cancer. People with albinism can develop freckles, moles, lentigines, and sunburn after exposure to sunlight.
They are also frequent, in some types of albinism, the appearance of hemorrhages , especially nosebleeds and bleeding gums and after surgery.
Other problems are related to social stigmas that cause depression, stress and low self-esteem in albino people, as well as a certain social isolation.
Diagnosis of albinism
Genetic sequence analysis is the most definitive test for the diagnosis of albinism. Albinism in the fetus can also be detected by amniocentesis between 16 and 18 weeks of pregnancy. Chediak-Higashi syndrome (CHS) is detected by a polymorphonuclear leukocyte function test. For Hermansky-Pudlak syndrome (HPS), bleeding time, platelet aggregation, and electron microscopy tests are performed.
Albinism Treatment
There is no specific treatment to reverse albinism, there is only treatment to prevent or correct complications derived from it.
Glasses, low vision therapies or bifocals can meet the needs of patients to some extent. UV-protective sunglasses, hats, or sun visors can also be used to help reduce photophobia and some visual complications . In the case of babies or children with strabismus, the use of patches or corrective glasses are useful.
To avoid sunburn , sunscreens with a sun protection factor (SPF) preferably greater than 50 are used. It is also important to monitor and care for skin changes and moles, as these changes can cause skin cancer.
There are also some conditions secondary to albinism that may require surgical intervention to be resolved, such as nystagmus, severe strabismus or retinal detachment.
References:
Albinism: Symptoms and Causes (2018). Mayo Clinic. https://www.mayoclinic.org/es-es/diseases-conditions/albinism/symptoms-causes/syc-20369184
Albinism: Types, Symptoms and Causes (2021). Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/21747-albinism#:%7E:text=Albinism%20is%20a%20rare%20genetic,pale%20skin%2C%20eyes%20and%20hair
Bashour, M. (2020). Albinism: Background, Pathophysiology, Epidemiology. Medscape. https://emedicine.medscape.com/article/1200472-overview
Das, S. (2021). Albinism. MSD Manuals. https://www.msdmanuals.com/en/home/skin-disorders/pigmentation-alterations/albinism
What is Albinism? (s.f.). National Organization for Albinism and Hypopigmentation. https://www.albinism.org/information-bulletin-what-is-albinism/
Albinism (2021). NHS. https://www.nhs.uk/conditions/albinism/
