By Siti Marlina Binti Saleh, Lecturer, School of Allied Health Sciences
Kacang parang
You can enjoy “kacang parang” or fava bean in a variety of forms: either cooked, eaten raw or dried as your choice of snack. Besides its yummy taste, this bean is rich in Vitamin B and minerals such as phosphorus, iron, magnesium and it is also high in fibre.
However, despite being highly nutritious, these beans are not safe for everyone to consume. People with Glucose-6-phosphate dehydrogenase (G6PD) deficiency may be badly affected after consuming the fava beans. Even worse, the pollen of fava beans may badly affect people who are G6PD deficient.
Glucose-6-phosphate dehydrogenase (G6PD)
G6PD is an enzyme that guards the red blood cells’ membranes in the body. It protects the red blood cells from being broken down upon exposure to infection, medication such as anti-malaria, naphthalene in mothballs, and after consumption of fava beans. Most people with G6PD deficiency usually do not experience any symptoms until they are exposed to any one of these triggers which can lead to lysis of their red cells and eventually causing hemolytic anaemia.
This enzyme deficiency is inherited from the parents where gene mutation has resulted in inadequate production of the G6PD enzyme. Its inheritance is determined by the X chromosome. That is why male are mostly affected while females are the carriers.
G6PD Screening test – Fluorescent spot test
In Malaysia, all babies are screened for G6PD deficiency upon birth. The Medical Laboratory Test (MLT) technician performs the G6PD Screening test on a blood sample that is sent to the Hematology laboratory. The MLT technician will mix the dried-blood sample with a reagent. The MLT technician will then view the reaction paper under UV light. The NADPH produced by the G6PD enzyme will produce a fluorescence that is visible under UV light. The detection of fluorescence shows that the G6PD enzyme is present. If it does not fluoresce, it means that you are G6PD deficient.
Treatment
For people with G6PD deficiency, they will not have any symptoms unless they are exposed or have ingested the causative agents such as fava beans, certain drugs, infection or others. The treatment is based on the causes. G6PD deficiency is a lifelong condition. However, it does not affect the child’s growth and development or has other negative effects.