Monash Researcher Discovers Linkage between Gene and Severe Skin Disease

A severe skin disorder particular to ethnic Han Chinese Malaysians has recently gained attention due to the presence of the same gene in Thais and Koreans, a Monash University Sunway campus researcher has found.

Professor Nathorn Chaiyakunapruk said that the Steven-Johnson Syndrome (SJS) has a high mortality rate and severity of pain experienced by those afflicted.

SJS is clinically similar to another skin disease, Toxic Epidermal Necrolysis (TEN). SJS and TEN are both forms of a severe skin reaction which can sometimes even result in death if not treated early. Mortality can be as high as 25 %, Prof Chaiyakunapruk, a Professor of Health Economics at the Discipline of Pharmacy, Monash University Sunway campus said.

By one commonly accepted definition, Prof Chaiyakunapruk elaborated, changes affecting less than 10 % of the body surface area is categorised as SJS, while changes affecting more than 30 % of body surface area is categorised as TEN. An involvement of one to 30 % of the body surface area is considered an SJS-TEN overlap,” he explained.

“While we cannot say for certain which ethnic group has the highest incidence of exhibiting SJS and TEN symptoms, it is shown that ethnic Han Chinese, Thais and Koreans have a higher disposition likely due to the presence of a specific gene in their make-up,” he said.

Prof Chaiyakunapruk’s research, recently published in the prestigious “JAMA Dermatology”, has crucially drawn the link of the genetic predisposition towards SJS and TEN.

“My research has found that a certain gene in the human body increases a person’s affinity to developing SJS and TEN,” he said.

SJS and TEN can be brought on by a number of reasons, but one of the most common triggers is the consumption of certain drugs.

“This gene actually makes a body more reactive to a certain drug, causing the body to react and exhibit symptoms of SJS,” he explained.

Prof Chaiyakunapruk’s research findings have identified this particular gene, making it possible for healthcare practitioners to test for it before deciding on the administration of particular drugs.

“Detecting this gene can be done using a genetic test. If the gene is found to exist in the person, then doctors will not give that medication,” he said.

“There is a long list of drugs that can trigger the onslaught of SJS, but one of the main drugs that is well-known for this trigger-effect is carbamazepine, an antiepileptic or anti-seizure drug,” said Prof Chaiyakunapruk.

He said carbamazepine was a very effective and popular drug to administer for people afflicted with a wide range of diseases, hence why it is often prescribed by healthcare practitioners in this region.

“In this region, namely South China, Malaysia and Thailand, the probability of suffering from this severe cuticle reaction is three in 1000 patients. That is a relatively high number,” he said.

His breakthrough discovery of this gene in the human body will hopefully encourage more research into ways to reduce the occurrence of SJS and TEN.

“Currently, it is already possible to run a test to detect this gene but it is costly to have to run every patient through it before administering drugs, so governments will need to decide if this additional cost is worth it, versus the consequences of SJS and TEN and its associated cost for treatment,” said Prof Chaiyakunapruk.

“More research and work needs to go into this before we can find a financially practical method of testing patients before administering the right drugs,” he said.

Prof Chaiyakunapruk earned his bachelor degree in Pharmaceutical Sciences from Chulalongkorn Univesity and Doctor of Pharmacy (Pharm.D.) from the University of Wisconsin-Madison. He completed his Ph.D. in Pharmaceutical Outcomes Research and Policy Program from the University of Washington in Seattle, USA. Best known for his research expertise in a wide range of research topics in pharmacy, medicine, and public health, Prof Chaiyakunapruk has more than 60 international publications in highly-esteemed journals. He said he hopes to be able to share his vast experience and knowledge in research to Monash University students, making research something that was both intellectually appealing as well as fun, to the students.