If you notice below, under “common considerations in determining whether to screen for disorders”, congenital heart defects and pulse oximetry screening would apply to all 5 considerations. Also, further down, is a list state mandated screenings, including the secondary or expanded screenings, and their incidence rates. These diseases are more rare than CHD, which incidence rate is 1 in 100. Can’t wait to see the day when pulse oximetry screening for CHD and other respiratory issues is mandated in every state!
Newborn screening is the process of testing newborn babies for treatable genetic, endocrinologic, metabolic and hematologic diseases. Newborn screening has been adopted by most countries around the world, though the lists of screened diseases vary widely.
Common considerations in determining whether to screen for disorders:
- disease that can be missed clinically at birth
- high enough frequency in the population
- delay in diagnosis will induce irreversible damages to the baby
- simple and reasonably reliable test exists
- treatment or intervention that makes a difference if the disease is detected early
The following tests are mandated (required to be performed on every newborn born in the state) in most of the United States. According to the U.S. Centers for Disease Control, approximately 3,000 babies with severe disorders are identified in the United States each year using newborn screening programs at current testing rates. States vary, and not all tests are required in every state, and a few states mandate more than this.
- Endocrine disorders: Congenital adrenal hyperplasia (CAH), Congenital hypothyroidism
- Blood cell disorders: sickle-cell disease (SS)
- Inborn errors of carbohydrate metabolism: Galactosemia
- Inborn errors of amino acid metabolism: Phenylketonuria (PKU), Maple syrup urine disease (MSUD), Homocystinuria
- Inborn errors of organic acid metabolism: Biotinidase deficiency
According to this resource, the only tests mandated in every state are the following:
- CH – Congenital hypothyroidism
- H-HPE – Benign hyperphenylalaninemia
- PKU – Phenylketonuria/hyperphenylalaninemia
- HEAR – Hearing
- GALT – Transferase deficient galactosemia
In nearly all of the United States, the newborn screening program is a division of the state health department. State law mandates collecting a sample by pricking the heel of a newborn baby to get enough blood (typically, two to three drops) to fill a few circles on filter paper labeled with names of infant, parent, hospital, and primary physician. It is usually specified that the sample be obtained on the second or third day of life, after protein-containing feedings (i.e., breast milk or formula) have started, and the postnatal TSH surge subsided. Every hospital in the state as well as independent midwives supervising home deliveries are required to collect the papers and mail each batch each day to the central laboratory.
The state health department agency in charge of screening will either run a laboratory or contract with a laboratory to run the mandated screening tests on the filter paper samples. The goal is to report the results within a short period of time. If screens are normal, a paper report is sent to the submitting hospital and parents rarely hear about it.
If an abnormality occurs, employees of the agency, usually nurses, begin to try to reach the physician, hospital, and/or nursery by telephone. They are persistent until they can arrange an evaluation of the infant by an appropriate specialist physician (depending on the disease). The specialist will attempt to confirm the diagnosis by repeating the tests by a different method or laboratory, or by performing other corroboratory or disproving tests. Depending on the likelihood of the diagnosis and the risk of delay, the specialist will initiate treatment and provide information to the family. Performance of the program is reviewed regularly and strenuous efforts are made to maintain a system that catches every infant with these diagnoses. Guidelines for newborn screening and follow up have been published by the American Academy of Pediatrics.
The following list includes most of the disorders detected by the expanded or supplemental newborn screening by mass spectrometry. This expanded screening is not yet universally mandated by most states, but may be privately purchased by parents or hospitals at a cost of approximately US$80. Perhaps one in 5,000 infants will be positive for one of the metabolic tests below (excluding the congenital infections).
The following conditions and disorders were recommended as “core panel” by the 2005 report of the American College of Medical Genetics (ACMG). The incidences reported below are from their report, pages 143-307, though the rates may vary in different populations.
Blood cell disorders
Sickle cell anemia (Hb SS) > 1 in 5,000; among African-Americans 1 in 400
Sickle-cell disease (Hb S/C) > 1 in 25,000
Hb S/Beta-Thalassemia (Hb S/Th) > 1 in 50,000
Inborn errors of amino acid metabolism
Tyrosinemia I (TYR I) Argininosuccinic aciduria (ASA) Citrullinemia (CIT) Phenylketonuria (PKU) > 1 in 25,000
Maple syrup urine disease (MSUD) Homocystinuria (HCY)
Inborn errors of organic acid metabolism
Glutaric acidemia type I (GA I) > 1 in 75,000
Hydroxymethylglutaryl lyase deficiency (HMG) Isovaleric acidemia (IVA) 3-Methylcrotonyl-CoA carboxylase deficiency (3MCC) > 1 in 75,000
Methylmalonyl-CoA mutase deficiency (MUT) > 1 in 75,000
Methylmalonic aciduria, cblA and cblB forms (MMA, Cbl A,B) Beta-ketothiolase deficiency (BKT) Propionic acidemia (PROP) > 1 in 75,000
Multiple-CoA carboxylase deficiency (MCD)
Inborn errors of fatty acid metabolism
Long-chain hydroxyacyl-CoA dehydrogenase deficiency (LCHAD) > 1 in 75,000
Medium-chain acyl-CoA dehydrogenase deficiency (MCAD) > 1 in 25,000
Very-long-chain acyl-CoA dehydrogenase deficiency (VLCAD) > 1 in 75,000
Trifunctional protein deficiency (TFP) Carnitine uptake defect (CUD)
Miscellaneous multisystem diseases
Cystic fibrosis (CF) > 1 in 5,000
Congenital hypothyroidism (CH) > 1 in 5,000
Biotinidase deficiency (BIOT) > 1 in 75,000
Congenital adrenal hyperplasia (CAH) > 1 in 25,000
Classical galactosemia (GALT) > 1 in 50,000
Newborn screening by other methods than blood testing
Congenital deafness (HEAR) > 1 in 5,000
Source: Wikipedia