What are the newborn screenings that detect genetic and infectious diseases?

Newborn screenings are a set of important tests performed on infants before they leave the hospital, aimed at the early detection of serious medical conditions that may not show clear symptoms at birth. These screenings are essential because prompt diagnosis and treatment can prevent long-term health problems or even early death [1].

Main Types of Screenings

Newborn screenings include several main types, each aimed at detecting a specific category of diseases:

• Blood tests (heel prick): These tests are performed by taking a few drops of blood from the baby's heel. They aim to detect genetic and metabolic disorders. Some countries test for at least 30 of these conditions, such as phenylketonuria (PKU), galactosemia, and congenital hypothyroidism [1] [2]. For example, phenylketonuria (PKU) is a metabolic disorder that prevents the body from processing the amino acid phenylalanine. If left untreated, it can lead to severe intellectual and developmental disabilities. Early diagnosis allows for a special diet that prevents these complications [2]. Likewise, screenings detect conditions such as 21-hydroxylase deficiency, a genetic disorder that affects the adrenal glands and can cause severe sodium loss in infants [3].
• Hearing screening: This test measures the baby's response to sounds to detect any hearing impairment [1].
• Pulse oximetry (skin test): This test measures oxygen levels in the blood and can indicate the presence of critical congenital heart defects [1].

Importance of Early Detection and Rapid Intervention

The paramount importance of these screenings lies in their ability to identify medical conditions before symptoms appear, allowing treatment to begin immediately. Many conditions detected by these screenings, such as Severe Combined Immunodeficiency (SCID), can cause serious disabilities or death if not treated early [2]. For example, infants with untreated SCID may not survive past the age of two, but with early detection and treatment, they can live longer, healthier lives [2].

What Happens After the Screening?

If the initial screening shows that your baby may have a certain condition, it is essential to follow up promptly with a healthcare provider for confirmatory tests. If a condition is confirmed, treatment must be started immediately [1]. The specific tests performed may vary depending on the geographic region, so it is important to inquire about the screenings available in your area [1].

For more information about newborn screenings, you can visit Newborn screenings: Early detection of genetic and infectious diseases (Arabic).

When Should Emergency Care Be Sought?

In rare cases, serious symptoms may appear that require immediate medical attention, especially if related to conditions like severe 21-hydroxylase deficiency (the salt-wasting type). Symptoms that require emergency care include poor feeding, weight loss, dehydration, and severe vomiting in the first few days after birth [3]. These symptoms may be life-threatening and require urgent medical intervention.

Medical references

• Newborn Screening
• What disorders are newborns screened for in the United States?
• 21-hydroxylase deficiency: MedlinePlus Genetics