Newborn Screening/NEWBORN HEARING

Newborn Screening:Rationale
 early identification of congenital metabolic disorders that can lead to
mental retardation or death if not treated
 involves collection of a few drops of blood by heel prick after the first
48 hours of life
Why is it important to have newborn screening?
 Most babies with metabolic disorder look normal at Birth.
 One will never know that the baby has the disorder until the signs and
symptoms are manifested.
When is newborn screening done?
 Ideally done on the 48th to 72nd hour of life
 May also be done 24hrs from birth
How is newborn screening done?
 Using the heel prick method, a few drops of blood are taken from the
baby’s heel
 Blotted on a special absorbent filter card
 Blood is dried for 4 hours and sent to the Newborn Screening Center.
Which disorders are screened?
In the Philippines:
 Congenital Adrenal Hyperplasia (CAH)
 21 hydroxylase deficiency
 Congenital Hypothyroidism (CH)
 Primary Congenital Hypothyroidism
 Glucose 6-Phosphate Dehydrogenase (G6PD) deficiency
 Galactosemia
 Phenylketonuria (PKU)
 Maple syrup urine disease (MSUD)
Expanded Newborn Screening
 Current panel of (6) disorders + Cystic fibrosis
 Biotinidase Disease
 Organic acid Disorders



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Fatty acid oxidation disorders
Amino acid Disorders
Urea cycle Disorders
Hemoglobin Disorders

CLINICAL MANIFESTATIONS AT BIRTH
DISORDERS

APPEARANCE AT BIRTH

CAH

Hyperpigmentation, ambiguous genitalia on female
infant

CH

NORMAL

GAL

NORMAL

PKU

NORMAL

G6PD

NORMAL

When do typical signs and symptoms appear?
DISORDERS

GOLDEN PERIOD

CAH

7 – 14 DAYS

CH

4 WEEKS

GAL

2 WEEKS

PKU

3 WEEKS

G6PD

Exposure to agent causing Hemolysis

What happens to unscreened and untreated babies?
DISORDERS

UNSCREENED/UNTREATED

CAH

DEATH

CH

Severe growth and mental
retardation

GAL

DEATH/Cataract

PKU

Severe mental retardation

G6PD

Severe Anemia, Jaundice, Kernicterus

Congenital Adrenal Hyperplasia (CAH)


Congenital adrenal hyperplasia (CAH), also termed adrenogenital
syndrome in older literature, is a common inherited form of adrenal
insufficiency.



This group of diseases is due to mutations (genetic defects) in the
genes coding for several enzymes needed to produce vital adrenal
cortex hormones.

Congenital Hypothyroidism (CH)
 a partial or complete loss of function of the thyroid gland
(hypothyroidism) that affects infants from birth (congenital).
 occurs when the thyroid gland fails to develop or function properly.

GALACTOSEMIA

 Galactose


Component of dietary sugars



Converted to GLUCOSE for energy storage (glycogen) and energy
production

 Galactosemia results from a deficiency of Galactose-1-phosphate
uridyltransferase (GALT)


Enzyme responsible for converting galactose to glucose

Phenylketonuria



Phenylalanine




Essential amino acid found in most protein diets

Tyrosine





Produced from phenylalanine



Component of substances that regulate body functions
(hormones/ pigment)

Inefficient production of tyrosine from phenylalanine






Complete absence or profound deficiency of phenylalanine
hydroxylase (PAH) enzyme activity

Very high elevations of blood Phenylalanine


Excessive amounts of waste products of phenylalanine
(phenylketones) in the urine



Gives the urine a characteristic “mousy” odor

Low serum levels of tyrosine


Disturbance in hormone and pigment production

G6PD DEFICIENCY
 Function of G6PD
 Certain food and drug have oxidant properties that causes cell
damage
 Produce H2O2 and other reactive oxidizing products (OH+)
 In the red blood cells (RBC), the only mechanism to neutralize
oxidative substances is through the G6PD activity
 Without G6PD, RBC’s undergo HEMOLYSIS when exposed to oxidative
stress!
Maple syrup urine disease (MSUD)
 is a metabolism disorder passed down through families in which the
body cannot break down certain parts of proteins.
 Urine in persons with this condition can smell like maple syrup.
SCREENING AND CONFIRMATORY TEST
DISORDERS

SCREENING TEST

CONFIRMATORY TEST

CAH

17 OHP

^ 17 OHP

CH

TSH

DEC. T4/INC.TSH

GAL

GALACTOSE

DEC. GALT

PKU

PHENYLALANINE

DEC. PAH

G6PD

G6PD

DEC. G6PD

TREATMENTS
DISORDERS

TREATMENTS

CAH

SUPPLEMENTATION

Glucocorticoids,
Mineralocorticoids,
NaCl

CH

SUPPLEMENTATION

Thyroid Hormone

GAL

AVOIDANCE

Galactose/Lactose

PKU

AVOIDANCE

Protein Diet

G6PD

AVOIDANCE

Oxidative drugs, food,
chemicals

Newborn Hearing Screening Test
 helps to identify babies who have permanent hearing loss as early as
possible.
 This means parents can get the support and advice they need right
from the start.
 One to two babies in every 1,000 are born with permanent hearing loss
in one or both ears.
 This increases to about 1 in every 100 babies who have spent more
than 48 hours in intensive care. Most of these babies are born into
families with no history of permanent hearing loss.
 Permanent hearing loss can significantly affect a baby's development.
Finding out early can give these babies a better chance of developing
language, speech, and communication skills. It will also help babies
make the most of relationships with their family or carers from an early
age.
When is the newborn hearing test done?
 before you are discharged in hospital.
 In some areas it will be done by a health professional, healthcare
assistant or health visitor within the first few weeks.
 Ideally, the test is done in the first four to five weeks, but it can be
done at up to three months of age.
How




is the newborn hearing test done?
The test is called the automated otoacoustic emission (AOAE) test.
It takes just a few minutes.
A small soft-tipped earpiece is placed in your baby's ear and gentle
clicking sounds are played. When an ear receives sound, the inner part
(called the cochlea) responds. This can be picked up by the screening
equipment.

Does my baby have to have the newborn hearing test?
 It's highly recommended, but you don't have to accept it.
 If you decide not to have the screening test, you will be given
checklists to help you check on your baby's hearing as they grow older.
 If you have any concerns, you should speak to your health visitor or
GP.

When will we get the results?
 You will be given your baby's hearing test results as soon as the test is
done. If your baby has a clear response in both ears, they are unlikely
to have permanent hearing loss.
 However, the newborn hearing test doesn't pick up all types of
permanent hearing loss. Children can also develop permanent hearing
loss later on, so it's important to check your child's hearing as they
grow up. The checklist in your baby's personal child health record (red
book) tells you how to do this.
What does it mean if my baby is referred to a hearing specialist?
 If the screening test results do not show a clear response from one or
both of your baby's ears, an appointment will be made with a hearing
specialist at an audiology clinic. Even if this happens, it doesn't
necessarily mean your baby has a permanent hearing loss.
 A hearing specialist should see you within four weeks of your baby's
hearing test. It's very important that you attend the appointment in
case your baby does have permanent hearing loss.
What does it mean if my baby is referred to a hearing specialist?
 Your audiologist will usually be able to explain the results at the end of
the appointment.
 They will explain what the results mean for your baby's hearing and
whether any further tests are necessary.