Morquio syndrome, also known as Mucopolysaccharidosis Type IV (MPS IV), is a rare, inherited, and metabolic disorder in which the body cannot process certain types of sugar molecules called glycosaminoglycans (AKA GAGs, or mucopolysaccharides). This birth defect, which is autosomal recessive, is a type of lysosomal storage disorder. The buildup of GAGs in different parts of the body causes symptoms in many different organ systems. This disorder is of two types: Type A and Type B, generally called Morquio A and Morquio B syndrome or MPS IVA and MPS IVB. The basic and immediate difference between these two types is the gene product involved. Type A is recognised by a malfunction in the GALNS gene, while Type B involves a malfunction of the GLB1 gene.
Although people suffering from Morquio A syndrome appear to be healthy at birth, the symptoms of this uncommon but serious disease start appearing between 1 to 3 years of age of the child. Physical growth slows and often is stunted around the age of 8. Skeletal abnormalities like a bell-shaped chest, a flattening or curvature of the spine, shortened long bones, etc., is observed. Restricted breathing, joint stiffness, and heart disease are also common. Children with the more severe form of MPS IV may not live beyond their twenties or thirties. There is no treatment which could be meted out to the patients without their side effects. Currently, prenatal identification and enzyme replacement therapy are the only two accepted treatments for Morquio A Syndrome, out of which the latter has been observed to cause adverse side effects due to a strong immune response towards the enzyme that is administered. Yet, there is still no news about treating Morquio B Syndrome.
Recently, a research team at Saint Louis University tried to counteract the adverse effect of enzyme treatment therapy. Researchers found that feeding mice oral GALNS before enzyme replacement therapy reset the body’s immune system to decrease the immune response towards it and to diminish the accumulation of toxic materials in the body. Although, this improvised therapy has not been tested in humans.
“This model could be extrapolated to other lysosomal storage disorders where the immune response hinders the effectiveness of enzyme replacement therapy,” said Adriana M. Montaño, Ph.D., associate professor of paediatrics at Saint Louis University, who led the research team. Scientists from SLU’s Departments of Pediatrics, Biochemistry and Molecular Biology, Molecular Immunology and Microbiology, Pathology, Internal Medicine and Center for Health Outcomes Research gave their strenuous efforts into this project.
Hopefully, this noble and brilliant work can liberate the people suffering from Morquio A Syndrome without making them meet any effects that can impact them lifelong. The influence of such outstanding research will pave the way for performing studies and experiments to find a treatment for Morquio B Syndrome too.
Dibyasha Das