Type of test Blood

 Normal findings

 Negative

Possible critical values

 Positive for any one of the tests

 Test explanation and related physiology

 Newborn screening (NBS) is the practice of testing every newborn for certain harmful or potentially fatal disorders that are not otherwise apparent at birth. The Recommended Uniform Screening Panel (RUSP) is a list of disorders recommended for testing by the government. In most states, this testing is mandatory. NBS tests take place in the first 12 to 48 hours of life. If these diseases are not accurately diagnosed and treated, they can cause cognitive impairment, severe illness, and premature death in newborns. Many of these are metabolic disorders, often called inborn errors of metabolism. Disorders that may be detected through screening include endocrine and hematologic diseases

Shortly after a child’s birth, a sample of blood is obtained from a heel stick, and the blood is analyzed. The sample, called a blood spot, is tested at a reference laboratory. It is generally recommended that the sample be taken after the first 24 hours of life. Some tests such as the one for phenylketonuria (PKU) may not be as sensitive until the newborn has ingested an ample amount of the amino acid phenylalanine, which is a constituent of both human and cow milk, and after the postnatal thyroid surge has subsided. This is generally after about 2 days.

Tandem mass spectrometry can detect the blood components that are elevated in certain disorders, and it is capable of screening for more than 20 inherited metabolic disorders with a single test. The following disorders are typically included in newborn screening programs:

• PKU: An inherited disease, PKU is characterized by deficiency of the enzyme phenylalanine hydroxylase, which con verts phenylalanine to tyrosine. Phenylalanine is an essential amino acid necessary for growth; however, any excess must be degraded by conversion to tyrosine. An infant with PKU lacks the ability to make this necessary conversion. Thus phenylalanine accumulates in the body and spills over into the urine. If the amount of phenylalanine is not restricted in infants with PKU, progressive mental retardation results. A low-phenylalanine diet will need to be followed throughout childhood and adolescence and perhaps into adult life. (Incidence: 1 in 10,000 to 25,000.)

• Congenital hypothyroidism: Affected babies without treatment experience retarded growth and brain development. If the disorder is detected early, a baby can be treated with oral doses of thyroid hormone to permit normal development. (Incidence: 1 in 4000.)

• Galactosemia: Babies with galactosemia lack the enzyme that converts galactose into glucose, a sugar the body is able to use. As a result, milk and other dairy products must be eliminated from the diet. Otherwise, galactose can build up and cause blindness, severe mental retardation, growth deficiency, and even death. (Incidence: 1 in 60,000-80,000.) There are several less severe forms of galactosemia that may be detected by newborn screening. These may not require any intervention.

• Sickle cell anemia: Sickle cell disease is an inherited blood disease in which red blood cells stretch into abnormal sickle shapes. This can cause episodes of pain, damage to vital organs (e.g., the lungs and kidneys), and even death. Young children with sickle cell anemia are especially prone to certain dangerous bacterial infections. (Incidence: about 1 in 500 African American births and 1 in 1000 to 1400 Hispanic American births.)

 • Biotinidase deficiency: Babies with this condition do not have enough biotinidase, an enzyme that recycles biotin (one of the B vitamins) in the body. This deficiency may cause seizures, poor muscle control, immune system impairment, hearing loss, mental retardation, coma, and even death. If the deficiency is detected early, however, problems can be pre vented by biotin administration. (Incidence: 1 in 126,000.)

 • Congenital adrenal hyperplasia: This is actually a group of dis orders resulting in a deficiency of adrenal hormones. It can affect the development of the genitals and may cause death. Lifelong treatment through hormone supplementation man ages the condition. (Incidence: 1 in 12,000.)

 • Maple syrup urine disease (MSUD): Babies with MSUD are missing an enzyme needed to process the amino acids leu cine, isoleucine, and valine (present in protein-rich foods such as milk, meat, and eggs) that are essential for the body’s normal growth. When these are not processed properly, they can build up in the body, causing urine to smell like maple syrup or sweet, burnt sugar. These babies usually have little appetite and are extremely irritable. If not detected and treated early, MSUD can cause mental retardation, physical disability, and even death. A carefully controlled diet free of high-protein foods can prevent these outcomes. (Incidence: 1 in 250,000.)

• Homocystinuria: This metabolic disorder results from a deficiency in cystathionine β-synthase, responsible for the metabolism of methionine and homocysteine. If untreated, it can lead to dislocated lenses of the eyes, mental retar dation, skeletal abnormalities, and hypercoagulability. However, a special diet combined with dietary supplements may help prevent most of these problems. (Incidence: 1 in 50,000-150,000.)

 • Tyrosinemia: Babies with this disorder cannot metabolize tyrosine. If it accumulates in the body, it can cause mild retar dation, language skill difficulties, liver problems, and even death from liver failure. A special diet and sometimes a liver transplant are needed to treat the condition. Early diagnosis and treatment seem to offset long-term problems. (Incidence: not yet determined.)

 • Cystic fibrosis: This is an inherited disorder expressed in the lung and gastrointestinal tract that causes cells to release a thick mucus, leading to chronic respiratory disease, problems with digestion, and poor growth. There is no known cure; treatment involves trying to prevent the serious lung infections associated with it and providing adequate nutrition. (Incidence: 1 in 2000 white births.)

• Toxoplasmosis: Toxoplasmosis is a parasitic infection that can be transmitted through the mother’s placenta to an unborn child. The disease-causing organism, which is found in under cooked meat, can invade the brain, eye, and muscle, possibly resulting in blindness and mental retardation. (Incidence: 1 in 1000.)

Certain other rare disorders can also be detected and may include Duchenne muscular dystrophy, HIV, and neuroblastoma. Hematologic disorders such as glucose-6-phosphate dehydrogenase (G6PD) deficiency and thalassemia can also be identified.

Most, but not all, states require newborns’ hearing to be screened before they are discharged from the hospital. The hearing test involves placing a tiny earphone in the baby’s ear and measuring his or her response to sound (p. 398, evoked potentials).

Interfering factors

 • Premature infants may have false-positive results because of delayed development of liver enzymes.

 • Infants tested before 24 hours of age may have false-negative results.

 • Feeding problems may cause false-negative results.

 Procedure and patient care

Before

* Inform the parents about the purpose and method of the test.

 • Assess the infant’s feeding patterns before performing the test. An inadequate amount of protein ingested before performing the test can cause false-negative results.

During

• Place a few drops of blood from a heel stick in each circle on the filter paper.

 After

* Inform the parents that if test results are positive they will be notified by their healthcare provider, and further testing or treatment will be recommended.

Abnormal findings

- Metabolic diseases

- Endocrine diseases

- Hematologic diseases

اخر الاخبار

اخبار العتبة العباسية المقدسة

مجلة تسليم تدعو الباحثين والأكاديميين للمشاركة في أعدادها القادمة

المجمع العلمي يواصل إقامة محاضراته الأسبوعية في مقام الإمام المهدي (عجل الله فرجه)

جامعة الكفيل تطلق الدورة التدريبية الصيفية لطلبة كلية الهندسة التقنية

استعدادًا لزيارة الأربعين العتبة العباسية المقدسة تعقد الورشة التنسيقية الرابعة الخاصة بمراكز إرشاد التائهين

المزيد

الآخبار الصحية

دراسة علمية تكشف مفاجأة حول الأسباب الحقيقية للسمنة

دراسة: الأطباء يتجاهلون "سببا شائعا" لارتفاع ضغط الدم

نظامك الغذائي غني بالبروتين؟.. احذر هذه الآثار الجانبية

لا تتجاهلها.. أعراض تنذرك بأنك مهدد بالإصابة بالسكري

المزيد

الآخبار التكنلوجية

ISOFIX: معيار الأمان الذهبي لمقاعد الأطفال في السيارات

هل المحرك الأكبر دائمًا الأفضل للسيارة؟

اختبارات ناجحة لمحرك "VK-800" الروسي وتطويره لطائرة بايكال الخفيفة

رئيس إنفيديا: الذكاء الاصطناعي الصيني "محفز للتقدم العالمي"

المزيد

مواضيع ذات صلة

Neuron-specific enolase (NSE)

Natriuretic peptides

Mycoplasma pneumoniae antibodies, IgG and IgM

mononucleosis rapid test (Mononuclear heterophil test, Heterophil antibody test, Monospot test)

microglobulin (Beta2-microglobulin [β2m], Alpha-1-microglobulin, Retinol binding protein)

Immunoelectrophoresis

Graded Agglutination Reactions

Blood Group Antigens

Evaluation of Platelet Function In Vitro with PFA-100

Platelet Alterations

microalbumin (MA)

methylated septin 9 DNA (mSEPT9, ColoVantage)