Tests for early detection of diseases and disorders in infants
New born screening tests are a very vital method of early detection of disorders or latent diseases in new borns and infants, long before the symptoms begin to appear. It is with the help of these early lab tests that detection, subsequent testing and treatment of several potentially life threatening ailments can be made possible.
Categories of screening tests:
Based on their utility and diseases they detect, newborn screening tests can be classified into the following three types:
- Screening tests for Infectious Diseases: these tests are done on an infant only when the mother has been known to have been infected by some agents or the baby is showing some symptoms of infection.
- Screening Tests for Congenital Disorders: these tests are done to determine if any disorders are present in the baby from birth, irrespective of whether the symptoms are seen or not. There are a series of 29 tests under this category.
- Screening tests for genetic disorders: these tests are done to find out if the baby is suffering from any inherited disorders, mainly due to specific genes or due to family history or even due to increased probability as a result of being born into a specific race or ethnic group.
Types of neonatal screening tests:
Screening tests trivia:
Screening tests for infants began first in the 1960s.
While neonatal screening is mandatory in many states across US and UK; there are many countries which do not follow these screenings as a regular procedure.
Apart from physical examination, there are two types of screening tests for new borns. These are:
- Blood tests: Today, infants can be screened for almost 55 diseases and disorders using just a spot of blood, with a single prick. The prick is given to the baby’s heel and a few drops of blood are taken as sample; which are then sent for lab analysis. The blood tests are performed for one or all of the above mentioned categories and done between 24 hours to seven days after birth.
- Hearing test: This test is done to check the hearing abilities of the infant. It is done using a tiny earpiece or microphone, which is placed inside the baby’s ear; all while the baby sleeps.
Disorders detected by newborn screening tests:
The following are the disorders that are indicated by the neonatal tests.
- Biotinidase deficiency
- congenital hypothyroidism
- Cystic fibrosis
- Congenital adrenal hyperplasia
- Human immunodeficiency disease (HIV)
- Glucose 6 phosphate dehydrogenase deficiency (G6PD)
- Sickle cell disease and other hemoglobin disorders.
- Amino acid metabolism disorders: these include – Citrullinemia, Maple syrup urine disease, Arginosuccinic academia, Homocystinuria, Tyrosinemia type I, Phenylketonuria (PKU)
- Fatty acid metabolism disorders: These include - Trifunctional protein deficiency, Carnitine uptake deficiency, Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency, Long-chain L-3-hydroxyacyl-CoA dehydrogenase deficiency and Very long-chain acyl-CoA dehydrogenase deficiency (VLCAD)
- Organic acid metabolism disorders: Glutaric acidemia type I, Isovaleric academia, 3-Hydroxy-3-methylglutaric aciduria (HMG), Beta ketothiolase deficiency, 3-Methylcrotonyl-CoA carboxylase deficiency (3MCC), Multiple carboxylase deficiency (MCD), methymalonic academia, Propionic academia
The results of these screening tests may vary from one lab to another and thus, doctors need to be consulted for correct interpretation of the same.