Written by ◆ Yang Qianni and compiled by ◆ Liang Yingxiu
G6PD deficiency is commonly known as favismia, and as the name suggests, broad beans are one of the triggering factors.
Sometimes, parents try to be cautious by telling their children to avoid beans, but accidentally give them broad bean products.
(Kuala Lumpur News) The official scientific name of favismia is Glucose-6-Phosphate Dehydrogenase Deficiency (G6PD deficiency). It is one of the common inborn errors of metabolism and is caused by the gene encoding G6PD. Caused by genetic defects.
The so-called metabolic disease mainly involves metabolic enzymes (enzymes), that is, too much or too little of them will lead to too much or too little of the products of the metabolic cycle (such as glucose, protein or fat), affecting metabolism. For example, babies who lack the glucose-metabolizing enzyme galactose enzyme may not be able to metabolize and absorb breast milk normally, resulting in delayed growth and development.
Contact triggers erythrocyte rupture
Consultant pediatrician Dr Vivian Thong Siew Peng pointed out that G6PD deficiency mainly involves the circulation of glucose. Human blood contains red blood cells, white blood cells, platelets and other cells, and G6PD is a very important enzyme in the process of red blood cell decomposition of glucose metabolism. This metabolic process produces a substance that protects red blood cells. Simply put, the function of G6PD is mainly to maintain the stability of red blood cells.
“When G6PD is lacking, red blood cells will become very unstable. At this time, if you are exposed to some triggers such as broad beans, it will easily cause the red blood cells to be damaged and ruptured, which means hemolysis will occur, leading to symptoms or dangerous complications.”
“In fact, most of the time, G6PD deficiency is asymptomatic. On the contrary, it will ‘show’ when hemolysis is induced, which can be mainly divided into neonatal jaundice and hemolytic anemia. When red blood cells are damaged and decomposed, bilirubin (bilirubin) will be released ), therefore patients with G6PD deficiency are more likely to develop severe jaundice than ordinary newborns. In children or adolescents, jaundice can also be manifested in darker urine, brown or cola-colored urine. As for hemolytic anemia Symptoms include paleness, shortness of breath, low blood pressure or shock.”
Newborn umbilical cord blood test
She said that according to a 2004 study by Universiti Kebangsaan Malaysia (UKM) published in the “Malaysian Journal of Pathology” and involving 15,277 newborn screenings, the average prevalence of G6PD deficiency in Malaysian baby boys and girls was respectively are 4.7% and 1.4%. Among 7,737 male infants, the prevalence rates of Malays, Chinese and Indians were 4.6%, 6% and 1.3% respectively.
“Studies also mentioned that 68% of newborns with G6PD deficiency develop jaundice.
One third are at risk of severe hyperbilirubinemia.
Despite phototherapy, the bilirubin level remains 250 μmol/L or higher.
It can be seen that G6PD deficiency is closely related to neonatal jaundice.
Therefore, if a newborn baby is diagnosed with G6PD deficiency,
Generally, patients need to stay in the hospital for observation for 5 days. “
She reminded that in order to avoid permanent damage caused by excessive bilirubin accumulation in the brain, especially auditory nerves and kernicterus, many countries, including Malaysia, screen newborns for metabolic diseases, including G6PD deficiency and congenital diseases. Hypothyroidism.
“The newborn screening method is simple. You only need to collect umbilical cord blood and apply it on filter paper for testing, and then send it to the laboratory for a fluorescent spot test.”
“Screening results can be divided into 3 categories: normal, deficient and intermediate or doubtful. Generally speaking, female babies with G6PD deficiency are rare and will usually undergo further diagnostic testing. All showing as intermediate Based on the results, both men and women will undergo further diagnostic testing.”
G6PD activity less than 10% is serious
She said the confirmatory test for G6PD deficiency is to measure the actual amount of G6PD activity. When G6PD activity is less than 10% it is considered severe, between 10% and 60% it is considered moderate deficiency, and above 60% it is considered mild deficiency. Sometimes, G6PD activity in patients with moderate and mild disease gradually increases with age, but patients with severe disease generally do not change much.
“G6PD deficiency is prevalent in areas including the Mediterranean, Africa, Asia and the Middle East. It is an X-chromosome recessive genetic disease. Most patients are male because the gene responsible for manufacturing G6PD is located on the X chromosome.”
Does not affect lifespan and mental health
Can be screened after birth
Human gender is determined by sex chromosomes, with males being XY and females being XX. When one of the X chromosomes has a G6PD defect, women still have another normal X chromosome that can “neutralize” the defect, while men have only one X chromosome and will get the disease as long as this X chromosome is abnormal.
Women who acquire an abnormal X chromosome will not develop the disease but will become carriers of the G6PD deficiency gene.
Tang Xiuping gave an example. When the father is a G6PD deficiency patient and the mother is normal, the son born will not inherit the disease, but the daughter will become a carrier. When a father has G6PD deficiency and a mother is a carrier, the son has a 50% chance of being affected, while the daughter has an equal chance of being affected or a carrier. If the father is unaffected and the mother is a carrier, the son has a half chance of being affected, and the daughter has an equal chance of being a carrier or unaffected.
She said that although it is a hereditary disease, G6PD deficiency is not included in the prenatal screening program because the result of this genetic defect is not simply “yes” or “no”. Even male patients with G6PD deficiency have different symptoms and severity. Therefore, no matter whether you have no family history or are not sure whether you are a carrier, you do not need to worry too much before giving birth. You can just screen the baby after birth.
Do not allow patients to come into contact with mothballs
“G6PD deficiency will not affect a child’s normal life span, mental state or height. As long as you pay more attention to avoid contact with substances that can induce hemolysis, you can be ‘immune’ for life.”
There is no clinical treatment that can normalize deficient G6PD activity. The main care is to prevent the occurrence of symptoms and avoid exposure to factors that can induce hemolysis.
“In my clinical experience, at least two or three patients have symptoms caused by eating broad bean products by mistake. Therefore, you need to pay attention to the ingredients when educating children or giving them food.”
In addition, mothballs should not be placed in places where patients come into daily contact, and mosquito coils, peppermint essential oil, violet liquid, and methylene blue that require ignition should also be avoided.
Aspirin causes hemolysis
She said that certain tuberculosis (tuberculosis) drugs, antipyretic and analgesics such as aspirin, sulfonamide antibiotics, anti-malarial drugs and certain diabetes drugs, as well as Chinese herbal medicines include skullcap, goldenrod, honeysuckle and pearl powder. etc. can cause hemolysis. Therefore, patients with G6PD deficiency need to inform their medical history when seeking medical treatment to ensure that the doctor prescribes appropriate drugs.
“Infection is also one of the causes. If a newborn is born with pneumonia or bacterial infection, coupled with the lack of G6PD, the bilirubin will rise very high. As for children or adult patients, if they appear pale, short of breath or If you have symptoms such as tea-colored urine, you must seek medical attention promptly to avoid entering a state of acute hemolytic anemia, which may lead to acute decline in renal function, hypotension, shock, or life-threatening conditions.”
Jaundice does not equal G6PD deficiency
Question 1. Is jaundice in newborns suffering from G6PD deficiency?
Answer 1.G6PD deficiency is an X-chromosome recessive genetic disease and one of the common inborn errors of metabolism. Neonatal jaundice is not the same as G6PD deficiency. 8 to 9 out of 10 newborns will have jaundice, with varying degrees of severity.
First of all, the life span of normal red blood cells is about 3 months, while the life span of newborn red blood cells is shorter, only 6 to 8 weeks. After birth, some of the red blood cells obtained from the mother during fetal life are old and need to be replaced, so they are destroyed by the spleen and release bilirubin. When bilirubin accumulates, it can cause the skin to turn yellow, which is jaundice.
Secondly, the fetus does not need to breathe on its own while it is still in the abdomen. All nutrients and oxygen are transported to the body through the umbilical cord. From the moment of birth, he has to be “self-reliant” and his metabolic rate will increase. However, the concentration of bilirubinase in his liver and gastrointestinal tract is not sufficient, so the process of excreting metabolites will be slower. To put it simply, the production and discharge are not directly proportional, causing the accumulation of metabolites such as bilirubin, resulting in more obvious jaundice.
When newborns also have G6PD deficiency, their red blood cells are prone to rupture and produce more bilirubin, so their jaundice index will be higher or last longer. Therefore, the standard care for newborns with G6PD deficiency is to stay in the hospital for 5 days. If the jaundice index is too high, phototherapy or even exchange transfusion is required.
Severe illness may require blood transfusion
Question 2. How to treat patients with G6PD deficiency?
Answer 2.Patients with G6PD deficiency are hospitalized with hemolysis and usually rely on intravenous infusion to replenish fluids. This is to dilute excessively ruptured red blood cells so that they can be excreted more easily and avoid renal blood vessel embolism, which may cause renal damage or ischemic shock.
If the condition is severe, blood transfusion or exchange transfusion may be required. If it is determined that the hemolysis is due to infection, antibiotics will be given.
G6PD deficiency does not require iron supplementation
Question 3. Do patients with G6PD deficiency need to supplement iron?
Answer 3.The cause of patients with G6PD deficiency is the lack of G6PD enzyme. The number of red blood cells is sufficient, but it is not stable enough, so iron supplementation is ineffective.