Newborn screening in the context of "Phenylalanine"

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⭐ Core Definition: Newborn screening

Newborn screening (NBS) is a public health program of screening in infants shortly after birth for conditions that are treatable, but not clinically evident in the newborn period. The goal is to identify infants at risk for these conditions early enough to confirm the diagnosis and provide intervention that will alter the clinical course of the disease and prevent or ameliorate the clinical manifestations. NBS started with the discovery that the amino acid disorder phenylketonuria (PKU) could be treated by dietary adjustment, and that early intervention was required for the best outcome. Infants with PKU appear normal at birth, but are unable to metabolize the essential amino acid phenylalanine, resulting in irreversible intellectual disability. In the 1960s, Robert Guthrie developed a simple method using a bacterial inhibition assay that could detect high levels of phenylalanine in blood shortly after a baby was born. Guthrie also pioneered the collection of blood on filter paper which could be easily transported, recognizing the need for a simple system if the screening was going to be done on a large scale. Newborn screening around the world is still done using similar filter paper. NBS was first introduced as a public health program in the United States in the early 1960s, and has expanded to countries around the world.

Screening programs are often run by state or national governing bodies with the goal of screening all infants born in the jurisdiction for a defined panel of treatable disorders. The number of diseases screened for is set by each jurisdiction, and can vary greatly. Most NBS tests are done by measuring metabolites or enzyme activity in whole blood samples collected on filter paper. Bedside tests for hearing loss using automated auditory brainstem response and congenital heart defects using pulse oximetry are included in some NBS programs. Infants who screen positive undergo further testing to determine if they are truly affected with a disease or if the test result was a false positive. Follow-up testing is typically coordinated between geneticists and the infant's pediatrician or primary care physician.

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Newborn screening in the context of Congenital disorder

A birth defect is an abnormal condition that is present at birth, regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can range from mild to severe. Birth defects are divided into two main types: structural disorders in which problems are seen with the shape of a body part and functional disorders in which problems exist with how a body part works. Functional disorders include metabolic and degenerative disorders. Some birth defects include both structural and functional disorders.

Birth defects may result from genetic or chromosomal disorders, exposure to certain medications or chemicals, or certain infections during pregnancy. Risk factors include folate deficiency, drinking alcohol or smoking during pregnancy, poorly controlled diabetes, and a mother over the age of 35 years old. Many birth defects are believed to involve multiple factors. Birth defects may be visible at birth or diagnosed by screening tests. A number of defects can be detected before birth by different prenatal tests.

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Newborn screening in the context of Cretinism

Congenital hypothyroidism due to iodine deficiency (ICD-11), or congenital iodine deficiency syndrome (CIDS, ICD-10), is a medical condition present at birth marked by impaired physical and mental development, due to insufficient thyroid hormone production (hypothyroidism) caused by insufficient dietary iodine during pregnancy. Iodine deficiency is one cause of underactive thyroid function at birth, called congenital hypothyroidism. If untreated, it results in impairment of both physical and mental development. Symptoms may include: goiter, poor length growth in infants, reduced adult stature, thickened skin, hair loss, enlarged tongue, a protruding abdomen, delayed bone maturation and puberty in children, mental deterioration, neurological impairment, impeded ovulation, and infertility in adults.

In developed countries, thyroid function testing of newborns has assured that in those affected, treatment with the synthetic thyroid hormone thyroxine is begun promptly. This screening and treatment successfully cures the disease.

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LINKED FROM (PARENTS)
← Congenital disorder ← Birth defect ← Congenital ← Congenital deformity ← Congenital abnormalities ← Birth defects ← Cretinism
LINKS TO (CHILDREN)
Public health → Screening (medicine) → Infant → Phenylketonuria → Phenylalanine → Intellectual disability → Robert Guthrie (microbiologist) → Filter paper → United States → Enzyme → Whole blood → Hearing loss → Congenital heart defects → Pulse oximetry → False positive → Geneticists → Pediatrician → Primary care physician →