The rare hereditary metabolic disorder Hurler (a Lysosomal Storage Disease) should be incorporated in the newborn screening program in the Netherlands. If required, children diagnosed with Hurler at the age of two months can have an early stem cell treatment, before damage to brains and backbone occurs. The Dutch Health Council makes this recommendation based on research by Dr. Jaap Jan Boelens of the UMC Utrecht.
The results of the study of Boelens, recently published in Blood, coincide with the opinion of the Health Council of April 8th 2015. After studying more than 200 international cases, researchers from the Wilhelmina Children's Hospital, (part of UMC Utrecht), concluded that patients should receive treatment as early as possible. In order to detect the disease at nearly stage, incorporation into the newborn screening is necessary.
Repair by stem cell therapy
The Hurler's syndrome, or mucopolysaccharidosis, is an inherited metabolic disorder which irreversibly damages children's organs resulting in death at a median age of 5-6 years (all die before the age of 12). The cause of the disease is a missing enzyme, and this can be 'fixed' by stem cell treatment. Patients will receive new bone marrow from a donor - nowadays mainly cord blood - which produces blood cells. White blood cells of the donor will produce the missing enzyme, and give it to the patient. Currently, doctors usually diagnose at the age of one to one and a half years. The patient will undergo a stem cell treatment as quick as possible, but the brains and the skeleton are generally already irreversibly damaged.
"By participating Hurler's syndrome in the newborn screening, we can already diagnose shortly after birth," says Jaap Jan Boelens. "The stem cell treatment can then take place at the age of two months. At that moment no damage has occurred. Furthermore, babies at that age can handle the treatment well. The side effects are minimal and treatment is safer than at a later age. "
The researchers made this recommendation based on a unique, international study. They followed 217 Hurler patients from around the world for an average of 9 years, (range 3 to 23 years), following their stem cell treatment. That's more than 70 percent of the total number of Hurler's patients worldwide. The researchers looked at developing intelligence, growth and a series of other physical properties. The health of these patients varied greatly. But the younger the patients had undergone the treatment, the better they were later in life.
Patients with Hurler's syndrome lack the enzyme α-L-iduronidase. The treatment is carried out using cord blood stem cells from unrelated donors. Since 2005 the UMC Utrecht has treated about 30 Hurler patients with a stem cell transplantation. In the Netherlands only 1 to 2 children are diagnosed with Hurler's syndrome per year. When incorporated into the newborn screening program, it is expected that number is likely to increase.