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Newborn Screening


Newborn Screening Baylor College of Medicine Anoop Agrawal, M.D. – PowerPoint PPT presentation

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Title: Newborn Screening

Newborn Screening
  • Baylor College of Medicine
  • Anoop Agrawal, M.D.

History of Newborn Screening
  • Began in the early 1960s
  • In 1961, Dr. Robert Guthrie developed an assay
    that could detect elevated levels of
    phenylalanine from a single drop of an infants
  • By 1965, over half of U.S. states had mandated
    PKU testing.
  • In 1995, most states screened for five disorders
    on average.

Expansion of Screening
  • In the 1990s, a new technology was developed
    known as tandem mass spectromety or MS/MS. This
    tool was able to screen for multiple biochemical
    markers (and hence disorders) using the same drop
    of blood.
  • In March 2005, the American College of Medical
    Genetics (ACMG) issued a report advocating for a
    mandated uniform panel of 29 disorders.
  • Prior to 2005, there was significant variablity
    amongst states in mandated screening ranging
    from zero to eight
  • By 2005, average number of conditions tested for
    by states increased to 24

Newborn Screening
  • Currently, how many genetic diseases are
    available for newborn screening?
  • The ACMG recommends states screen for 48 genetic
  • How many genetic diseases are currently screened
    for in the state of Texas?
  • As of Dec 09, Texas now screens for 28.

Extent of Mandatory Expanded Screening
Fourteen states do not mandate the expanded
testing. Parents are offered the testing through
a voluntary pilot program.
Screening in Texas
  • In 2005, HB790 was passed requiring expansion of
    the newborn screening program using the ACMG
    (American College of Medical Genetics)
    recommended panel as funds allowed.
  • As of Dec 09, the number of diseases screened
    increased to from 27 to 28.
  • Prior to that, only five diseases were screened
    PKU, hypothyroidism, galactosemia, sickle cell
    disease, congenital adrenal hyperplasia
  • In Texas, the Department of State Health Services
    (DSHS) operates the newborn screening case
    management program.

What conditions are screened for in Texas?
Newborn Screens for Texas
Incidence of inborn errors
  • Which of the following inborn errors of
    metabolism has the highest incidence?

A. congenital adrenal hyperplasia
B. congenital hypothyroidism
C. cystic fibrosis
D. galactosemia
E. phenylketonuria
1 in 12,000
1 in 3,500
1 in 4,000
1 in 60,000-80,000
1 in 10,000-25,000
Cystic fibrosis is now tested for in the state
of Texas.
Most common congenital defect
  • What is the most common congenital defect
    screened for?
  • The overall number one most common disease
    screened for is hearing loss.
  • It has an incidence of 2-3 in 1,000. Almost 20x
    more common than PKU
  • Currently screened for via OAE, ABER
  • DNA testing for hearing loss is already possible,
    but not yet employed.
  • 50 of newborns with hearing loss is due to
    genetic factors
  • 90 of newborns with hearing loss are born to
    hearing parents

Estimated Expansion Statistics
  • In Texas
  • Approximately 400,000 births a year
  • Approximately 800,000 specimens a year collected
    and tested
  • Follow-up on approximately 15,000 abnormal
    screens a year
  • Approximately 600 diagnosed cases per year

More is better, right?
  • Expanded newborn screen has raised concerns
    amongst some.
  • The identification of an abnormality that does
    not become clinically apparent is termed
  • Several of the newly added biochemical disorders
    maybe pseudodiseases.
  • Currently research suggests 3-MCC (is done in
    Texas) and SCAD (not in Texas) may not lead to
    significant disease.
  • Histidenemia is one that has been removed from
    screening due to lack of clinical disease in
    long-term studies

More is better, right?
  • This raises the question of How many more of the
    conditions added to the expanded list will become
  • Expanded screen for multiple rare disorders
    inevitably leads to more false positive results
    even when specificity is high
  • Indirect costs of expanded newborn screening
  • Parental anxiety
  • Cost of more diagnostic testing
  • Potential lack of meaningful intervention

Scenario One
  • You receive a phone call from the Texas
    Department of State Health Services. A six day
    old patient you saw yesterday has a positive
    newborn screening test for increased methionine
    and may have Homocystinuria. A review of the
    chart shows the child had a normal exam and
    seemed to be doing well.
  • What should you do next?
  • Where do you go for more information?

What do you do next?
  • Know what resources are available to assist you.
  • FACT sheets created by the AAP to provide
    pediatricians and parents with general
    information on the condition
  • Can be found on AAP website or Texas State
    Department of Health website
  • These are also available in spanish on the Texas
  • ACT sheets created by the American College of
    Medical Genetics. Provides physicians with the
    action plan diagnostic workup and clinical
    manifestations to watch for.
  • Also found on Texas website or on ACMGs website

FACT Sheets
  • Example of FACT sheet from Texas Department of
    State Health Services
  • FACT sheets on AAP website are geared more
    towards physicians.
  • This covers causes, symptoms, overview of
    treatment and outcomes.
  • This sheet by DSHS is designed for parents and

ACT Sheets
  • Example from ACMG for increased methionine -
    Texas Dept of State Health Services has adapted
    the same information on their website.
  • In this case, obtain quantitative amino acids,
    plasma homocysteine level and urine homocysteine
  • Consult with metabolic specialist.
  • Counsel and educate family about homocystinuria.
  • Report findings to newborn screening program.

Scenario Two
  • You are seeing a newborn infant in the Level I
    nursery. The parents tell you they do not want
    their child to have newborn screening testing.
    They feel that such testing is not part of Gods
    plan. What should you do?
  • In the state of Texas, a parent has the right to
    object to screening if it conflicts with their
    religious tenets or practices.

Scenario Three
  • You are examining a two week old female in your
    office. The family has recently moved to Houston
    from Miami. After your exam, you inform the
    parents the infant will need a newborn screen.
    The parents ask you why she needs a second
    screen? In Florida, their older child only had
    newborn screening performed once.
  • Texas mandates ALL infants have two newborn
    screens. The first must be collected between
    24-48 hours of life. The second may be performed
    between 7-14 days of life.
  • What if the baby is 6 months old and has only one
    newborn screen on file?
  • In Texas, every child must have 2 newborn screens
    documented by age of 12 months.

Hot off the presses!
The Future
  • Current screening relies on detecting biochemical
    markers via tandem mass spectrometry (MS/MS).
  • This methodology enabled expansion of newborn
    screening in an inexpensive, rapid and easy
  • The future lies in DNA-based screening.
  • This will undoubtedly raise the specter of
    diseases screened for along with requiring more
    of the pediatrician.
  • DNA testing also raises a host of privacy,
    societal and medical issues which will need to be

  • Tarini, BA, Freed GL. Keeping up with the
    newborn screening revolution. Contemporary
    Pediatrics 2007244, 36-49.
  • Texas State Department of Health Services,
  • National Newborn Screening and Genetics Resource
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