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Newborn Screening for Inherited Metabolic Disorders (Newborn screening)

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  • Modify Date:Modify Date:2020/07/29
  • Publish Date:Publish Date:2020/07/17
Newborn Screening for Inherited Metabolic Disorders (Newborn screening) 
    It can help your baby by detecting inherited metabolic abnormalities early, so your baby can have early treatment to reduce physical or cognitive impairment caused by the disease.

Dear parents, 
    Healthy children are the source of joy for a family. If a child becomes ill during the growth phase, it will often bring about different degrees of influence on the family and society. Therefore, we would like to remind you that it is essential for your child to receive newborn screening and related health screening services as soon as possible.
Through newborn screening, it can help children by detecting congenital metabolic abnormalities with inconspicuous symptoms and provide proper care in time to minimize damage to the body or cognition. 
    To determine if your baby is suffering from one of the selective metabolic disorders, the hospital will take a small amount of blood from your baby’s heel when the baby is 48 hours after birth. The sample will then send to the Newborn Screening Center designated by the Health Promotion Administration, Ministry of Health and Welfare for tests. Currently, the government provides subsidize on the following newborn screening conditions:
1.Congenital hypothyroidism: 
    Around one in every 3,000 newborns is diagnosed with this disorder. Newborns with hypothyroidism are almost asymptomatic and usually start developing symptoms at two to three months after birth. Hypothyroidism is the lack of thyroid hormones in the infant, thus affecting the brain and the development of the body. If left untreated 6 months after birth, most likely, the baby has severe intellectual disability, growth delay, and small body size. If detecting early and providing synthetic thyroid hormone within one to two months after birth, the baby can have a normal intellectual and physical development.
2.Phenylketonuria: 
    About one in every 35,000 newborns has is diagnosed with this disorder. Symptoms such as growth delay or the mold smell of the urine and body odor usually appear at three to four months after birth. Phenylketonuria can lead to severe intellectual deficiency. Phenylketonuria is a deficiency of the enzyme that metabolizes dietary protein. If detected early (within two weeks after birth), physicians can provide special diet and regular check-ups; most infants can have normal intellectual development.
3.Homocystinuria: 
    About one in every 100,000 to 200,000 newborns is diagnosed with this disorder. Infants with the disease are unable to metabolize dietary protein effectively. If left untreated, the baby may have complications such as skeletal deformity, learning, and intellectual disabilities, and thrombosis. With early detection and introduction of special diet and vitamin treatment, we can prevent that baby from the intellectual disability.
4.Galactosemia: 
    Around one in a million infants is diagnosed with classical galactosemia. Infants with the disease cannot metabolize galactose, and present vomit and drowsy after feeding, and damage to the eyes, liver, and brain. With early detection, dairy products that are free from lactose and galactose will replace breastfeeding or normal infant formula, to decrease the damage made from the disease. Mothers who have given birth to such a baby should avoid foods containing dairy or lactose such as milk/dairy products/offal during her next and following pregnancy. By doing so may eliminate the possibility of harming a fetus with such condition.
5.Glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency, favism):
    Out of every 100 infants, 3 are diagnosed with the disorder. It is the most common hereditary disease in Taiwan. This disease is mainly the abnormal metabolism of glucose in red blood cells. When an infant with this condition is exposed to certain substances (such as broad beans, naphthalene (mothballs), gentian violet, sulfa drugs, antipyretic, analgesic, etc.), he/she is susceptible to acute hemolytic anemia. Failure to receive timely treatment could lead to jaundice and subsequently, intellectual disabilities or death. Early detection and avoiding the substances mentioned above can reduce the damage to your baby. 
    To provide a more comprehensive screening service for newborns, since July 2006, in addition to the five conditions mentioned above, the government has prioritized the addition of six screening tests for congenital metabolic abnormalities as follows:
6.Congenital Adrenal Hyperplasia (CAH): 
    Around one in every 15,000 newborn infants is diagnosed with the disorder. The most common defect of this condition is due to adrenal 21-hydroxylase deficiency. Clinical presentation is based on the degree of missing "21-hydroxylase" quality and quantity, and is defined as (1) Salt-wasting type – most newborns of this type will lose too much sodium and result in an emergency. If left undiagnosed, it could lead to death. (2) Simple virilizing type – female newborns of this type have ambiguous genitalia, may experience failure to menstruate, over masculine, difficulties getting pregnant, and abnormal growth. Male newborns of this type would also experience abnormalities in growth. Without early detection, it can be difficult to treat physical and psychological conditions. (3) Nonclassic CAH – most symptoms of this type will start to show after infancy. Apart from the nonclassic congenital adrenal hyperplasia, the other types can be detected early via the screening and receive treatment to avoid fatality. When treated appropriately with supplements, the child can have normal development and growth.
7.Maple syrup urine disease: 
    About one in every 100,000 newborns is diagnosed with the disorder locally. It is named maple syrup urine disease because the patient’s body fluids and urine have the sweetness of maple syrup. Infants with this type of disease usually develop symptoms several days after starting feeding. The symptoms include vomiting, lethargy, loss of appetite, shortness of breath, jaundice, seizures, etc. In severe cases, the affected can experience unconsciousness and even death. This disease is due to the abnormal metabolism of certain branched-chain amino acids. The patient is unable to process branch-chain amino acids such as valine, leucine, and isoleucine. Early detection and treatment are vital for the newborn as it will allow a better chance of normal physical and intellectual growth for the child.
8.Medium-chain acyl-CoA dehydrogenase deficiency: 
    Less than one in every 300,000 newborns is diagnosed with the disorder locally. However, there is about one in every 15,000 newborns diagnosed in Europe, and it is one of the most common fatty acids metabolic disorders. Clinical symptoms usually appear in the first two years after birth. The baby is unable to metabolize a group of fats due to the lack of medium-chain acyl-coenzyme A dehydrogenase. The buildup of fats accumulates in the body and becomes toxic, causing damage to the brain and nervous system, triggers vomiting, liver enlargement, hypoglycemia, loss of consciousness, coma, seizures, etc. Although some patients show no symptoms, 25% of the cases may die in the first episode and are often misdiagnosed as sudden infant death. Early screening can prevent the onset of the disease. Combined with rapid treatment of hypoglycemia in the acute phase, and long-term treatment of providing carbohydrate snacks before bedtime, avoid fasting and actively treat unexpected situations such as an infection or gastroenteritis, the disease can be properly managed with good prognosis.
9.Glutaric acidemia type 1: 
    About one in every 100,000 newborns is diagnosed with the disorder locally. It is a rare disease related to the abnormalities of certain organic acids. Due to the lack of glutaryl-CoA dehydrogenase, the infant is unable to breakdown lysine and tryptophan normally. The buildup of toxins, such as glutaric acid in the bloodstream and tissues can cause progressive neurological symptoms and acute metabolic abnormalities. Usually the affected newborn may have no abnormalities or only asymptomatic enlarged head within a few months of birth. But in late infancy, the baby gradually shows symptoms of difficulties in movements, progressive athetosis, hypotonic, muscle stiffness, numbness, opisthotonos (backward arching of the limbs), etc. There may also be an acute episode of epilepsy or slumbering coma. Early detection and treatment are vital for the newborn. It allows the affected to have more normal physical and intellectual development.
10.Isovaleric acidemia: 
    About one in every 80,000 newborns is diagnosed with this disease locally. This is a rare disease that is related to the abnormalities of metabolizing a certain organic acid. The affected cannot normally breakdown leucine due to the lack of isovaleryl-CoA dehydrogenase. The buildup of isovaleric acid accumulates and damages the nervous system and hematopoietic system. According to the severity of the symptoms and the onset of the disease, they are divided into typical and atypical. The typical patient may be asymptomatic at birth but will gradually show symptoms of nausea, vomiting, lethargy, poor appetite and cramps. With a large amount of isovaleric acid accumulates in the body, the infant will have a distinctive odor of sweaty feet from the body or urine. If there is no correct diagnosis and treatment at this time, the patient will gradually become unconscious. The atypical patients have a late-onset and mild symptoms that are not obvious. It is often diagnosed one year after birth and sometimes misdiagnosed as other similar diseases. With early screening, the use of diet control and regular monitoring, the treatment has effective results.
11.Methylmalonic acidemia: 
    About one in every 100,000 newborns is diagnosed with this disease locally. It is a rare disease that is related to the abnormalities of metabolizing certain organic acids. The affected infant has abnormal function of methylmalonyl-CoA mutase or abnormal cobalamin metabolism that leads to a buildup of organic acids like methylmalonic acid and propionic acid etc. Such buildup can damage the nervous system, and in severe cases, it could cause ketoacidosis, hypoglycemia, hyperammonemia, and hyperglycemia. There is high mortality among newborns and infants. Early screening could detect and prevent the acute onset, replenish fluids at the right time, and avoid acidosis. For patients with abnormal cobalamin metabolism, vitamin B12 should be administered as treatment. For those not responding to vitamin B12, special infant formula and high-calorie diet are given to control the level of methylmalonic acid in the blood and urine at an acceptable range.
12.Citrullinemia type I 
    Citrullinemia type I is one of the urea cycle disorders. The patient often cannot metabolize ammonia and presents hyperammonemia. During infancy, the early symptoms are poor appetite, vomiting, drowsiness, restlessness, shortness of breath, etc. The condition usually changes rapidly, showing more serious neurological and autonomic nervous system problems. If not treated appropriately, most patients will die or have complications. In the long-term treatment, patients need to limit protein intake, use special infant formula to supplement growth and development, use medication to remove excess ammonia from the blood, and regularly monitor blood ammonia and others.
13.Citrullinemia type II: 
    Citrullinemia type II is caused by citrin deficiency. The neonatal onset of type II citrullinemia will experience cholestatic jaundice, abnormal liver function, elevation of several amino acid levels in the blood, galactosemia and hepatic steatosis, etc. Severe cases could present with delayed growth, abnormal bleeding or anemia, hypoglycemia, hepatomegaly, and even liver failure. Treatment includes taking fat-soluble vitamins, maintaining a high protein, and high-fat diet.
14.3-Hydroxy-3-Methylglutaric Aciduria (HMG CoA lyase deficiency): 
    It is a congenital disorder in which the body is unable to metabolize leucine normally. It is one of the organic acidemias. The affected is unable to produce the enzyme to process leucine, The accumulation of such organic acid in the body leads to a high blood ammonia level, causing acidosis and hyperammonemia that may kill or intellectually disable an infant. Apart from being unable to metabolize leucine, the affected is also unable to make ketones. This causes the patient is not able to cope with long-duration of fasting. If detected early, babies can have less dietary protein, have supplement with special infant formula, and avoid long duration of fasting. Therefore patient’s physical and intellectual development can still be normal.
15.Holocarboxylase synthetase deficiency: 
    It is a carboxylase deficiency due to inborn error of biotin metabolism. The affected infants often have symptoms such as difficulties in feeding, tachypnea, exfoliative dermatitis, loss of hair, lethargy, etc. In terms of metabolism, the patient can experience ketolactic acidosis, organic acidemia, organic aciduria, and hyperammonemia. Timely supplementation with biotin can prevent many complications. If left untreated, this condition can cause delayed development, seizures, coma, and may even become life-threatening.
16.Very Long Chain Acyl CoA Dehydrogenase Deficiency (LCAD): 
    This is a condition in which the body is unable to properly breakdown certain fats and transforms into energy, particularly during periods without food (fasting). Signs and symptoms can occur during infancy or childhood and include hypoglycemia, drowsiness, and muscle weakness. The affected babies are also at risk of serious complications such as liver abnormalities and life-threatening heart problems. Signs and symptoms during puberty or adulthood often include intermittent rhabdomyolysis (breakdown of muscle), muscle cramps, and pain. When the muscle is breakdown, a protein called myoglobin is released. Myoglobin passes through the kidney and excretes into the urine, thus making the urine red or brown. In terms of diet, frequent meals with smaller portions are recommended to avoid hunger. The main treatment principles include limiting the intake of long-chain fatty acids and carnitine supplementation.
17.Primary carnitine deficiency: 
    This disease is also known as carnitine transporter deficiency. About one in every 30,000 babies is diagnosed with the disease. Carnitine is responsible for bringing fatty acids into mitochondria to produce energy. Patients with primary carnitine deficiency may experience hyperammonemic encephalopathy before the age of one, and cardiomyopathy after the age of one. As long as the disease is diagnosed early, taking carnitine regularly can avoid the onset of those unwanted symptoms.
18.Carnitine Palmitoyltransferase I deficiency: 
    Carnitine Palmitoyltransferase I (CPT I) deficiency is a condition that prevents the body from using certain fats for energy, particularly during periods without food (fasting). The severity of this condition varies among affected individuals. Signs and symptoms of CPT I deficiency often appear during early childhood. The affected cannot effectively produce energy from fatty acids and leads to hypoketotic hypoglycemia. Patients with CPT I deficiency can also have an enlarged liver (hepatomegaly), liver malfunction, etc. Individuals with CPT I deficiency are at risk for nervous system damage, liver failure, seizures, coma, and sudden death. The prevention of hypoglycemia reduces the risk of nervous system damage. In order to prevent hypoglycemia, infants need to increase the feeding frequency during the day, and then add corn starch during the night. Patients should not go on for more than 12 hours fasting especially when they are sick or undergoing specific medical treatment such as surgery. Adult patients need to be on high sugar and low-fat diet to ensure that the body uses sugar as the main source of energy.
19.Carnitine Palmitoyltransferase II deficiency: 
    Carnitine Palmitoyltransferase II (CPT II) deficiency is a condition that prevents the body from using certain fats for energy, particularly during periods without food (fasting). The lethal neonatal form of CPT II deficiency becomes ill soon after birth. Infants with this form develop respiratory failure, seizures, liver failure, a weakened heart muscle (cardiomyopathy), an irregular heartbeat (arrhythmia), and hypoketotic hypoglycemia. The other forms can appear later during childhood. Treatment is mainly based on restricted intake of long-chain fatty acids, avoidance of hunger, preventing hypoglycemia, as well as adding more sugar to the diet to produce energy when needed. 20.Glutaric Acidemia type II: 
    This disorder is due to the lack of multiple acyl CoA dehydrogenase and causes metabolic problems with fatty acids and branched-chain amino acids. The affected newborns may have symptoms of low blood sugar (hypoglycemia), acidemia, muscle weakness, enlarged liver (hepatomegaly), etc. In addition, glutaric acidemia type II may also present with an odor resembling that of sweaty feet. Some affected individuals have less severe symptoms that begin later in childhood or adulthood. Treatment includes riboflavin and carnitine supplement, using a high carbohydrate, low fat and low protein diet, avoiding hunger, preventing hypoglycemia, as well as adding more sugar to the diet for energy when needed.
21.Propionic Acidemia: 
    Babies with the most severe form of propionic acidemia become apparent ill within a few weeks after birth. The signs and symptoms include poor feeding, vomiting, seizures, weak muscle tone (hypotonia), dehydration, lethargy, sluggishness, and brain damage, etc. The late-onset form of this condition is less common. The affected patients need to restrict protein intake, especially the amino acids that produce propionic acid. Therefore, in addition to a small amount of normal diet, special formulas are supplied to provide a sufficient supply of protein and calories for growth. 
    Before you receive the screening results, please do not let your baby get in contact with naphthalene (mothballs), and do not medicate the baby at will. If the baby has a health problem, be sure to consult your pediatrician. If the screening result of your baby comes back as a positive, it does not mean that the baby has the disease. The original blood collection hospitals or the confirmational referred hospital will assist your baby to undergo further testing within the shortest time. The screening results of the initial (re-) examination can be obtained in about 2 weeks after the blood collection. Please contact the original blood collection hospitals or search online(https://www.ntuh.gov.tw/gene-lab-nbsc/Index.actionhttps://www.cfoh.org.tw/https://www.tipn.org.tw/). For disease-related information, please call the Hotline:+886-2-23123456#71930; +886-2-87681020#15; +886-2-85962050#408.