Newborn screening is a crucial preventive measure for conditions such as intellectual disabilities and brain damage. In developed countries like the United States, the United Kingdom, Japan, and almost all European nations, newborn screening is a standard practice. Every newborn undergoes screening for a range of conditions using advanced technology known as Tandem Mass Spectrometry (MS/MS), which now allows for the screening of up to 40 metabolic genetic disorders, compared to just 2 previously.
In Thailand, newborn screening currently covers two conditions nationwide: congenital hypothyroidism (CH) and phenylketonuria (PKU). These are managed by the Department of Medical Sciences under the Ministry of Public Health but do not include other metabolic disorders.
Metabolic genetic disorders can present symptoms similar to other childhood illnesses and may affect one or multiple systems in the body. Common symptoms include neurological, gastrointestinal, and cardiac issues. Some conditions may not manifest until the child is older or may appear within hours after birth. Examples include:
- Maple syrup urine disease
- Phenylketonuria (PKU)
- Isovaleric acidemia
Patients may show symptoms as infants, such as loss of appetite, poor feeding, weight loss, high-pitched crying, tremors, and a maple syrup-like urine odor. Subsequently, a metabolic crisis may occur, with symptoms including drowsiness, mood swings, and vomiting. Without treatment, complications like seizures, brain swelling, or metabolic acidosis can arise, potentially leading to blindness, brain damage, or death. Untreated patients often survive only a few months.
Q: Is it necessary for newborns to be screened?
A: Every newborn should undergo metabolic genetic disorder screening to detect potential abnormalities before symptoms arise, allowing for timely treatment. Parents interested in expanded newborn screening services should discuss this with their child’s healthcare provider.
Q: At what age can a newborn be tested?
A: Metabolic genetic disorder screening can be performed on infants aged 3-5 days who have received at least four feedings. The test requires only 2-3 drops of blood from the baby’s heel.
Q: What are the benefits of screening?
A: Early diagnosis and treatment of metabolic disorders can significantly improve treatment outcomes and prevent intellectual disabilities and brain damage. Developed countries have found that expanded newborn screening is more cost-effective compared to the expenses associated with managing intellectual disabilities, benefiting both the state and families.
Expanded screening can identify many more preventable conditions that are not included in standard screening programs, such as Inborn Errors of Metabolism (IEM), which can cause intellectual disabilities or death if untreated. These conditions are rare and often present with non-specific symptoms, leading to delayed diagnosis and treatment. The goal of newborn screening is to detect these conditions before symptoms appear or while they are still minimal, allowing for diagnosis and treatment within two weeks, thus preventing death or disability.
Many of the 40 conditions tested for are genetic disorders caused by recessive genes. Even if there is no family history of these conditions, parents may still be carriers or come from similar genetic backgrounds. A newborn may initially show no symptoms but later develop signs such as lethargy, poor feeding, vomiting, labored breathing, acidemia, seizures, coma, or eventually brain damage.
Brain abnormalities result from a lack of enzymes needed to break down substances in the body, leading to the accumulation of toxins or the inability to produce energy. Early diagnosis before symptoms develop allows for timely treatment, helping to prevent complications and improve long-term quality of life.
