Mother fights daughter’s rare disease

IN OCTOBER 2012, 41-year-old Joselyn Taruc finally learned that her 2-year-old daughter Queen Zina is afflicted with Hurler Syndrome, a rare and progressive genetic disorder that causes her to develop a large head, dark skin, coarse facial features (bulging forehead, depressed nasal bridge, broad mouth, square jaw), short neck, enlarged abdomen, clawed hands, crouched stance and to suffer from vision impairment, hearing loss and stunted growth.

The outlook for children with Hurler Syndrome is grim: they suffer from organ dysfunction particularly of the heart (valve problems and narrowed arteries), bones (misshapen spine and joints), lungs (frequent infection, airway blockages, sleep apnea) and in some cases of the brain (developmental abnormalities, learning difficulties and intellectual disabilities).

Despite being just 5 years old, Queen Zina has been in and out of the hospital for various ailments—recurrent fluid buildup in her head, abnormal heart murmur (she suffers from mild mitral regurgitation), pneumonia and ear infections.

“The reality that my youngest will also die early is difficult for me and I am not going to get ready for my youngest child’s death because I am just not ready to accept that, yet. She has to keep on fighting for her health as I will keep on fighting for access to treatment for her disease,” said Taruc whose 6-year-old first-born son died from complications of cerebral palsy in 2006.

Largely ignored

A rare disease like what Queen Zina has is largely ignored due to poor economic potential and are thus said to be “orphaned.” It is not surprising for most biomedical research companies to focus on developing treatments for common diseases as this would maximize the possibility of them recouping research and development costs.

As a result, the gap between common- and rare-diseases drugs eventually widened to the point where few or no treatments were available for rare conditions.

Taruc said: “In my conversations with doctors, I found that a bone-marrow or cord-blood transplant is the only treatment at the moment that shows promise against the effects of Hurler Syndrome. However, aside from being very expensive, the procedure also carries a high risk of developing life-threatening complications. Besides, it may not undo the damage the disease has already done.”

Fortunate

She related that she was just fortunate that when she sought the assistance of doctors at the Philippine Children’s Medical Center and the Philippine Society for Orphan Disorders, she was referred to the University of the Philippines-National Institutes of Health’s Institute of Human Genetics, which in turn, helped Queen Zina include in Genzyme’s International Charitable Access program (Genzyme is one of the few companies that developed life-saving therapies for ultra-rare diseases).

With the enzyme replacement therapy she is currently receiving every week, Taruc said there is improvement in her daughter’s swollen spleen and liver, joint mobility, breathing, and sleep apnea.

The ERT infusion takes about 4 hours.

Taruc said: “She really helped me realize what’s important. We regularly visit all her 10 specialists and despite my husband’s meager pay as a truck driver, I see to it that my baby gets treatment on time so I borrow money from friends or seek financial assistance from charitable institutions.”

Lacks enzyme

Hurler Syndrome occurs when the body lacks a particular enzyme that breaks down glycosaminoglycans (GAGs), a type of sugar molecule utilized by our cells to help build bones, cartilages, tendons, corneas of the eyes, skin and other types of connective tissues. GAGs also help with many other cellular functions, including growth control, organ development and signaling between cells.

Normally, GAGs are eventually transported to the cell’s digestive system—called lysosomes—wherein the enzymes inside break them down into their basic components.

In children with Hurler Syndrome, the GAGs are not broken down completely and as a result, accumulate in the cells. This damages the different tissues and organs of the body.

When too many GAGs accumulate, organs and tissues become damaged or do not function properly.

The ERT mimics the missing enzyme and during infusion, it stops the progressive accumulation of GAGs, resulting in the delay of Hurler Syndrome’s progression in the organs most affected by this disease.

Taruc and the rest of parents with children suffering from rare disorders are currently depending on a handful individuals and companies for various support. For years several bills, which seek to establish a comprehensive and sustainable health system for rare diseases, have remained pending before both houses of Congress.

Hurler Syndrome is inherited, which means the disease is passed on by the parents to their child. If both parents carry the defective gene related to this condition, each of their children has a 25 percent chance of developing the disease.

Persons with Hurler Syndrome do not make a substance called lysosomal alpha-L-iduronidase. This type of enzyme helps break down long chains of sugar molecules called glycosaminoglycans or GAGs. These molecules are found throughout the body, often in mucus and in fluid around the joints.

Without the enzyme, GAGs build up and damage organs, including the heart. Symptoms can range from mild to severe.