3 “Orphan” Genetic Disorders found in the Philippines

Written by: Elizabeth Fernandez

Cartoon by: Briane Delo

Defined as genetic disorders affecting less than 1 in 20,000 individuals, rare or “orphan” disorders are unique afflictions in the Philippines. While individuals with “common” genetic disorders themselves are often stigmatized and marginalized in society, individuals with orphan disorders have the added trouble of little information and understanding of their affliction that often lead to them being isolated, especially in the face of elusive medical help in the country. Here are some orphan disorders found in the Philippines to educate yourself about some of the rarest conditions in this country and Earth:

Maple Syrup Urine Disease (MSUD)

Named after the characteristic sweet-smelling odor of urine, MSUD is the most common congenital error of metabolism in the Philippines while also being considered an “orphan” or rare disorder with it affecting 1 in 185,000 infants. MSUD stems from an enzyme dysfunction affecting the metabolism of several key amino acids leucine, isoleucine, and valine. In effect, infants tend to showcase poor feeding, vomiting, lethargy, and seizures, and can quickly progress to coma and death, but these can also develop in juvenility. Current treatment involves strict dietary management to avoid the aforementioned amino acids with supplementations often offered. Liver and kidney transplants are also an option. Early detection is key for early treatment as there is no cure at the moment (De Castro-Hamoy et al., 2017). 

Gaucher Disease (GD)

Affecting 1 in 57,000-100,000 individuals in the Philippines, GD is caused by a deficiency of the enzyme glucocerebrosidase (due to  mutations in the GBA1 (glucosidase beta acid) gene), leading to the abnormal accumulation of a type of fat called glucocerebroside in various organs, especially the spleen, liver, and bone marrow. This leads to a myriad of issues like  damage, enlargement of these organs, and other complications, including anemia, bleeding disorders, bone pain and fractures, lung problems, and neurological symptoms. There are 3 main types: (1) most common and mild affecting the spleen and liver, (2) severe and rapidly progressing to the brain and spinal cord starting from infancy, and (3) intermediate and affecting visceral organs and brains that affects adults and children. Current treatment options include enzyme replacement therapy, substrate reduction therapy, and bone marrow transplantation (Chiong et al., 2018).

Hunter Syndrome (HS)

Also known as Mucopolysaccharidosis type II, HS is an extremely rare X-linked metabolic disorder caused by a deficiency of iduronate-2-sulfatase (I2S), which is responsible for breaking down certain glycosaminoglycans (GAGs) in the body, leading to GAG accumulation. It has an incidence of 0.3–0.71 in 100,000 live births but are mostly seen in men while women who are afflicted are often due to random X chromosome inactivation resulting in a mosaic of normal and affected cells. It has a varied age of onset and symptoms typically include developmental delays, coarse facial features, enlargement of the liver and spleen, skeletal abnormalities, joint stiffness, and a decrease in cognitive and/or motor skills. GAGs accumulation in the brain also causes speech and vision impairments. Current treatments include enzyme replacement therapy, substrate reduction therapy, which aims to reduce the production of GAGs, and stem cell transplantation (Chiong et al., 2017).

​