About Newborn Screening
Newborn screening is the practice of testing every newborn for certain harmful
or potentially fatal disorders that aren't otherwise apparent at birth.
With a simple blood test, doctors often can tell
whether newborns have certain conditions that eventually could cause problems. Although
these conditions are rare and most babies are given a clean bill of health, early
diagnosis and proper treatment sometimes can make the difference between lifelong
impairment and healthy development.
Which Tests Are Offered?
Newborn screening varies by state and is subject to change, especially given advancements
in technology. However, the disorders listed here are those usually included in newborn
screening programs:
- phenylketonuria (PKU)
- congenital hypothyroidism
- galactosemia
- sickle cell disease
- biotinidase deficiency
- congenital adrenal hyperplasia (CAH)
- maple syrup urine disease (MSUD)
- tyrosinemia
- cystic fibrosis (CF)
- MCAD deficiency
- severe combined immunodeficiency (SCID)
- toxoplasmosis
All newborns will also have a hearing
screening.
Phenylketonuria (PKU)
Phenylketonuria (PKU) is a metabolic disorder. Metabolism is the
process in the body that converts the fuel from
food into energy needed to do everything from moving to thinking to growing. A metabolic disorder is any disease caused by an abnormal
chemical reaction in the body's cells.
Babies with PKU are missing an enzyme that's needed to process phenylalanine. Phenylalanine
is an amino acid necessary for normal growth in kids and for normal
protein use. Amino acids are the "building blocks" for the proteins that make
up our muscles and other important parts of our bodies.
If too much phenylalanine builds up, it damages brain tissue and can cause developmental
delay.
When PKU is detected early, feeding an infant a special formula low in phenylalanine can prevent intellectual
disability. A low-phenylalanine diet is needed throughout childhood and adolescence
and sometimes into adult life. This diet cuts out all high-protein foods, so people
with PKU often need to take a special artificial formula as a nutritional substitute.
Congenital Hypothyroidism
The thyroid, a gland at the front of the neck, releases special chemicals called
hormones that control metabolism and growth. These hormones control
how fast the body uses up energy and are also key factors in helping kids grow.
Babies with congenital hypothryoidism don't have enough thyroid hormone. The condition
can cause slow growth and brain development.
If congenital hypothryoidism is detected early, a baby can be treated with
oral doses of thyroid hormone.
Galactosemia
Babies with galactosemia lack the enzyme that converts galactose (one of two sugars
found in lactose) into glucose, the major source of energy for the
body's cells.
For a baby with galactosemia, milk (including breast
milk) and other dairy products must be removed from the diet. Otherwise, galactose
can build up in the body and damage cells and organs, leading to blindness, severe
intellectual disability, growth deficiency, and even death.
Many less severe forms of galactosemia may not require any treatment.