When Lysosomes 'Malfunction', The Body Gets Sick

By Hazlinda Hamzah A lysosome is an organelle found in the cytoplasm of most cells. As lysosomes are subcellular organelles responsible for the physiologic turnover of cell constituents, their malfunction result in Lysosomal Storage Disease (LSD). This is the first of two features on LSD. KUALA LUMPUR, Feb 18 (Bernama) -- The Lysosomal Storage Disease, known as LSD, results when the lysosome, which is a specific organelle in the body's cells, malfunctions. LSD is characterised by the accumulation of undigested or partially digested macromolecules, which ultimately results in cellular dysfunction including the nervous system, connective tissue and others. To the layperson, terms such as Metachromatic Leukodystrophies, Multiple Sulfatase Deficiency and Galactosialidosis, are foreign. Some may say that these terms make no sense, and since they are too difficult to comprehend, these terms continue to be ignored. However, these rather unfamiliar words have proven to be grim to the unfortunate few, as they refer to a rare group of genetic disorders that fall under the category of LSDs. According to the medical fraternity, over 50 LSDs have been described. Some types of LSD include the Fabry, Gaucher, MPS and Pompe diseases. DIFFICULT TO DIAGNOSE According to Kuala Lumpur Hospital's Dr L.H. Ngu, a specialist in LSD, the disease is caused by an inherited genetic problem and is very rare. "It causes a malfunction of the enzymes in lysosomes, which should function to rid the cells of their waste," he said. The clinical geneticist and metabolic pediatrician said wastes collected in the lysosomes of the cells will disrupt the cell functions. "When this disease manifests, it will result in developmental delay, movement disorders, seizures, dementia, deafness and blindness, among other signs," he said. Dr Ngu also said it takes longer for an adult to show signs of LSD but they are not spared the severity of the disorder. NO EASY TASK The task of diagnosing the LSD by doctors and geneticists is not easy, said the LSD specialist. "The lysosome is an organelle in the cell and it helps to process the waste. There are more than 40 types of enzymes in a human body needed to break down different types of molecules. "The LSD is caused by the deficiency of a particular lysosome enzyme activity," he explained. As there are some 45 types of inter-related diseases make up the family of LSD diseases, Dr Ngu said, diagnosing LSD is a difficult task because the early symptoms are very similar to more common diseases. He said the problem grows bigger when genetic mutation causes an inability to synthesize thus lysosome accumulates and the cells simultaneously accumulate as well. The disease sometimes progresses slowly and outward signs are easily overlooked. "And because of all that, crucial treatment time is lost," Dr Lock explained. BEFORE BIRTH LSD effects can begin even before birth and it can be so severe that young patients normally do not survive. Some succumb at a very early age. In some cases, it can be milder and develop over time, according to the specialist. Those born with this inherited disease and survive it into their early years, will face a variety of complications that will be a continuous struggle for both their families and themselves. "Patients have to endure lengthy hospital stays and varying treatment courses. Sadly, there is no known cure available for LSD, and by large, treatment is symptomatic instead of dealing with the underlying enzyme problem, which is often treated as a secondary measure," he explained further. The patient eventually faces digression, losing the ability to walk and to talk. VIRAL ILLNESS "A viral illness may follow, or even a minor head injury may accelerate it. "The face of a LSD patient gets coarse eventually. They look older than they are supposed to, their eyes become cloudy and a small rash breaks out at the umbilical area. Some contract the Pompe disease. "This is when their heart gets enlarged and they develop a floppy body structure," Dr Ngu explained. -- BERNAMA