Screening for any disorder in individuals is a strategy used for identifying a disease before the onset of signs or symptoms, thus enabling earlier detection and management with the aim to reduce morbidity and mortality.

1. METABOLIC SCREENING IN
NEWBORN
By Dr Prabhakar, 1st year PG
Dept of Pediatrics,
Sri Venkateswara medical college,
Tirupati.

2. What is a screening test?
 Screening for any disorder in
individuals is a strategy used for
identifying a disease before the onset
of signs or symptoms, thus enabling
earlier detection and management
with the aim to reduce morbidity and
mortality.

3. • Screening babies for potentially treatable
conditions, not clinically evident.
• “Catch them early”
Aim to identify early before significant
morbidities set in.

4.  Screening tests
◦ Highly sensitive – but not so specific
◦ Large number to be tested
◦ Economically – draining.

5. Wilson and Jungner criteria for
disease screening
1. The condition sought should be an
important health problem.
2. There should be an accepted treatment for
patients with recognized disease.
3. Facilities for diagnosis and treatment
should be available.
4. There should be a recognizable latent or
early symptomatic stage.
5. There should be a suitable test or
examination.
6. The test should be acceptable to the

6. 7. The natural history of the condition,
including development from latent to
declared disease, should be adequately
understood.
8. There should be an agreed policy on
whom to treat as patients.
9. The cost of case-finding (including
diagnosis and treatment of patients
diagnosed) should be economically
balanced in relation to possible
expenditure on medical care as a
whole.
10. Case-finding should be a continuing
process and not a ‘once and for all’
project.

7. Metabolic
screening in
newborn
Antenatal period
Newborn
screening
Developmental,
Clinical,
Hearing screening
Metabolic
screening in
newborn
Congenital heart
defects.
High risk
screening
Autopsy
When??

8. Metabolic screening
In
newborn

9. Overview
 History
 Why it is needed?
 Indian scenario?
 What diseases to screen for?
 Brief description of common disorders
 When to do?
 Collection of samples and transportation
 Testing methods
 Is it cost effective?

10. How did it all start ?
 Father of newborn screening
 Screening test for phenylketonuria
(PKU) using bacterial inhibition assay.
 Filter paper (Guthrie card) system for
the collection & transportation of small
blood samples.
Robert Guthrie

11.  1960s :-Bacterial inhibition assay for phenylketonuria (PKU) by
Guthrie
Gradual evolution over the years
Over the next two decades:-
• Congenital hypothyroidism (CH)
• Sickle cell disease
• Congenital adrenal hyperplasia (CAH)
• Cystic Fibrosis
• Metabolic disorder
Today:- Screening as many as 40-50 conditions mandatory in
western countries

12.  Incidence of different inborn errors of metabolism
individually is less, but collectively they are
significant.
 Recent data suggest that the overall incidence of
metabolic disorder around the world is 1:1350.
 About 5 to 15 % of all sick neonates in NICU are
expected to have some Inborn Error of Metabolism
 If identified early, Child can lead a normal life, with
simple and effective treatments.
Why it is needed?

14. Indian scenario?
 The major hindrances for establishing
an effective screening program in
India are the
◦ costs involved,
◦ the non-availability of demographic data
and true incidence data of the disease in
question,
◦ massive annual birth cohort and
◦ the limitations of treatment modalities for
some of the diseases.

15. Which disorders to screen?
 Group – A : All newborns
 Group – B : screening in high risk
population
 Group – C : screening in resource rich
settings

16. Group – A
 disorders that can be strongly recommended in the
routine newborn metabolic screening in our
country.
◦ Congenital hypothyroidism,
◦ Congenital Adrenal Hyperplasia,
◦ G 6 PD Deficiency disorder

17.  Reasons :
◦ High incidence,
◦ Easily missed at birth,
◦ Definitive test and treatment available,
◦ If missed early - irreversible damage
◦ treatment - affordable in most settings in
the present scenario

18. Condition Incidence Diagnosis Treatment
CAH 1:2575 ELISA to
detect 17-
hydroxy-
progesterone
levels
Steroids
G6PD
Deficiency
1:15 to 1:200 Enzyme
assay to
detect G6PD
levels
Avoid
hemolysis
inducing
drugs/food
Congenital
Hypothyroi
dism
1:500-600 to
1:3400
ELISA to
detect
TSH/T4
levels
Thyroxine
supplementatio
n

19. Congenital hypothyroidism
 Most infants are asymptomatic at birth,
 This situation is attributed to partial
transplacental passage of maternal T4,
which provides fetal levels that are
approximately 33% of normal at birth.
 Despite this maternal contribution of T4,
hypothyroid infants still have a low serum
T4 and elevated TSH level

20.  Before neonatal screening programs,
congenital hypothyroidism was rarely
recognized in the newborn because
the signs and symptoms are usually
not sufficiently developed.

21.  Anterior and posterior fontanelle widely open
 Prolonged physiological jaundice beyond 2
weeks
 Cool extremities and mottling of skin
 Sluggish – feeds less and sleeps much
 Umbilical hernia
 Feeding difficulties
 Chocking spells
 Respiratory difficulties
 Constipation
 Edema of genitals and extremities

23.  If the defect is primarily in the thyroid, levels of TSH
are elevated, often to >100 mU/L.
 Serum levels of thyroglobulin are usually low in
infants with thyroid agenesis or defects of
thyroglobulin synthesis or secretion,
 Serum levels of thyroglobulin are elevated with
ectopic glands and other inborn errors of T4
synthesis

25. Congenital Adrenal
Hyperplasia
 More than 90% of CAH cases are caused by 21-
hydroxylase deficiency.
 21-hydroxylase deficiency is often undiagnosed in
affected males until they have severe adrenal
insufficiency
 17-hydroxyprogesterone levels in dried blood
obtained by heelstick and absorbed on filter paper
cards

27. Aldosterone and Cortisol
Deficiency
 These include
◦ progressive weight loss,
◦ anorexia,
◦ vomiting,
◦ dehydration,
◦ weakness,
◦ hypotension,
◦ hypoglycemia, hyponatremia, and hyperkalemia.
 These problems typically first develop in affected
infants at approximately 10-14 days of age.

28. Androgen Excess
 Affected females who are exposed in utero to high
levels of androgens of adrenal origin have
masculinized external genitalia
 Male infants appear normal at birth.
 Electrolyte and water imbalance at 1-4 weeks of
life with non specific signs – poor appetite,
vomitings and failure to grow

29. G 6 PD Deficiency disorder
 The most common manifestations of this disorder are
neonatal jaundice and episodic acute hemolytic
anemia
 The diagnosis depends on direct or indirect
demonstration of reduced G6PD activity in rbcs
 Enzyme activity in affected persons is ≤10% of
normal.
 G6pd deficiency should be considered in any
neonatal patients with hyperbilirubinemia and
borderline low g6pd activity.

30. Drugs to be avoided….
 Antibiotics
◦ Quinolones
◦ Sulfonamides
◦ Chloramphenicol
 Antimalarials – primaquine
 Analgesics – Asprin and Paracetamol
 Etc…..

31. Group – B
 The following disorders can be
screened in the high risk population
◦ Previous children with unexplained mental
retardation, seizure disorder,
◦ previous unexplained sibling deaths with
features suggestive of IEM,
◦ critically ill neonates,
◦ consanguinity
◦ newborns/ children with symptoms/signs/
investigations suggestive of IEM and

32. Features suggestive of IEM
 Sudden and rapid illness in a previously normal
baby precipitated by fever and vomiting
 Nonspecific unexplained features such as poor
feeding, lethargy, vomiting, hypotonia, failure to
thrive respiratory abnormalities, hiccups, apnea,
bradycardia and hypohypothermia, with normal
sepsis screen
 Rapidly progresslv encephalopathy of unknown
etiology, persistent or recurrent hypoglycemia,
intractable metabolic acidosis, unexplained
leukopenia or thrombocytopenia
 Hyperammonemia
 Organomegaly
 Peculiar odor

33.  Phenylketonuria
 Homocystinuria
 Alkaptonuria
 Galactosemia
 Sickle-cell anemia and other
hemoglobinopathies,
 Biotinidase deficiency
 Maple syrup urine disease
 Medium-Chain Acyl-Coenzyme A
Dehydrogenase Deficiency
(MCAD)
 Tyrosinemia
 Fatty Acid Oxidation Defects

34. Phenylketonuria
 PKU is caused by deficiency of Phenylalanine
hydroxylase (PAH).
 PKU is an autosomal recessive disorder with
incidences in Caucasian populations estimated at
1:10,000 but much less frequent in Asian and
African populations.
 If Untreated, phenylalanine deficiency will present
as developmental delay and intellectual disability.
 Analysis of plasma Phe and Tyr will demonstrate
significantly elevated Phe levels and elevated
Phe/Tyr ratio (typically greater than 2.5)

35. Homocystinuria
 Homocystinuria classically presents in the
first or second decade of life with
◦ marfanoid habitus,
◦ ectopia lentis,
◦ myopia,
◦ mental retardation, and
◦ increased risk for thromboembolic events.
 elevated methionine and possibly elevated
free homocysteine levels

36. Galactosemia
 Galactosemia denotes the elevated level of
galactose in the blood and is found in 3
distinct inborn errors of galactose
metabolism in one of the following
enzymes:
◦ Galactose-1-phosphate uridyl transferase,
◦ Galactokinase and
◦ uridine diphosphate galactose-4-epimerase.

37.  Classic galactosemia is a serious disease with
onset of symptoms typically by the second half of
the 1st wk of life.
 Without the transferase enzyme, the infant is
unable to metabolize galactose-1-phosphate, the
accumulation of which results in injury to kidney,
liver, and brain.

38. When to suspect?
 jaundice,
 hepatomegaly,
 vomiting,
 hypoglycemia,
 seizures,
 lethargy,
 irritability,
 feeding difficulties,
 poor weight gain or
failure to regain birth
weight,
 aminoaciduria,
 nuclear cataracts,
 vitreous hemorrhage,
 hepatic failure,
 liver cirrhosis,
 ascites,
 splenomegaly, or
 intellectual disability.

39.  The preliminary diagnosis- reducing substance in
several urine specimens
 Direct enzyme assay using erythrocytes
establishes the diagnosis.

40. Biotinidase deficiency
 Biotin is a required cofactor for acetyl-CoA, 3-
methylcrotonyl-CoA, propionyl-CoA, and pyruvate
carboxylases.
 estimated worldwide incidence of 1:50,000 to
1:75,000
 Biotinidase enzyme assay in serum will show
profound or partial deficiency for biotinidase

41. Tyrosinemia
 Tyrosinemia is an inborn error of Tyr metabolism
caused by deficiency of fumarylacetoacetate
hydrolase (FAH).
 Tyrosinemia can present as a severe infantile
progressive hepatopathy or later in infancy as a
renal tubulopathy with rickets, failure to thrive, and
hepatopathy.
 Untreated individuals can display porphyria-like
intermittent episodes of acute neurological crises
and progress to fatal hepatic failure and/or
hepatocellular carcinoma.

42. Group – C
 Group C ( Screening in Resource Rich
Settings): ‘Expanded Newborn screening’ for 30-
40 inherited IEM’s done by TMS can be offered to
the ‘well to do’ especially in urban settings where
facilities for sending samples to the TMS laboratory
are available.

43. Fatty acid oxidation disorders
 Carnitine / Acylcarnitine Translocase Deficiency (CACT)
 Carnitine Palmitoyl Transferase Deficiency Type I (CPT-
I) *
 2,4-Dienoyl-CoA Reductase Deficiency (DE-RED) *
 Long Chain Hydroxy Acyl-CoA Dehydrogenase
Deficiency
 Neonatal Carnitine Palmitoyl Transferase Deficiency
Type II
 Short-chain Acyl-CoA Dehydrogenase Deficiency
(SCAD)
 Short chain Hydroxy Acyl-CoA Dehydrogenase
Deficiency
 Trifunctional Protein Deficiency (TFP)
 Very Long Chain Acyl-CoA Dehydrogenase Deficiency
 Carnitine Uptake Deficiency (CUD) *

44. Aminoacid disorders
 Hypermethioninemia (MET)
 5-oxoprolinuria (5-OXO or Pyroglutamic Aciduria)
 Liver Disease
 Hyperalimentation
 Hyperprolinemia 1 and 2
 Pyruvate decarboxylase deficiency
 Hypervalinemia
 Hyperglycinemia
 Hyperornithinemia with Gyral Atrophy (HOGA) *

45. Organic acid disorders
 Isovaleric Acidemia (IVA)
 Glutaric Acidemia-Type I (GA-I)
 2-Methylbutyryl-CoA Dehydrogenase Deficiency (2MBG)
 3-Methylcrotonyl-CoA Carboxylase Deficiency (3MCC)
 3-Methylglutaconyl-CoA Hydratase Deficiency (3MGA)
 Methylmalonic Acidemias (MMA)
 Methymalonyl-CoA Mutase Deficiency (MUT)
 Some Adenosylcobalamin Synthesis Defects (CBL A, B/CBL C,D)
 Maternal Vitamin B12 Deficiency
 Mitochondrial Acetoacetyl-CoA Thiolase Deficiency (BKT)
 Propionic Acidemia (PROP)
 Malonic Aciduria (MAL)
 Multiple CoA Carboxylase Deficiency (MCD)
 Medium Chain Triglyceride (MCT) Oil Administration
 HMG Co A lyase deficiency
 2-methyl-3-hydroxybutyryl CoA dehydrogenase deficiency

46. Urea cycle disorders
 Argininemia (ARG)
 Argininosuccinic Aciduria (ASA Lyase)
 Carbamoylphosphate Synthetase Deficiency (CPS)
*
 Citrullinemia (CIT-I or ASA Synthetase)
 Ornithine transcarbamylse (OTC)
 N- Acetylglutamate synthatase (NAGS)
 Lysinuric protein Intolerance (LPI)
 Hyperammonemia, Hyperornithinemia,
Homocitrullinemia

47. When to do ?
 Screening should be done after 2 days and before
7 days of age .
 Infants screened before 24 hours of life should be
re-screened by 2 weeks of age to detect possible
missed cases.
 Sick and premature babies should also have
metabolic screening performed by 7 days of life.
 Gestational age and birth weight to be documented

48. • Radioimmunoassay for TSH and thyroxine (T4) :
congenital hypothyroidism.
• ELISA for congenital hypothyroidism and CAH
• Tandem mass spectrometry : inborn errors of
organic acids, fatty acids and amino acid
metabolism.
• Newer methods have been developed for using this
technique, to screen for lysosomal storage disorders
also.
• New biochemical and genetic tests have been
approved for newborn screening for cystic fibrosis
and severe combined immunodeficiency.
What tests?

49. Mass spectrometry (MS)
Mass spectrometry is a powerful analytical
technique that is used to identify unknown
compounds, to quantify known materials and to
elucidate the structure and chemical properties
of molecules
A mass spectrometer is a device that
measures the mass-to-charge (m/z) ratio of ions.
Tandem mass spectrometry (MS/MS)
A tandem mass spectrometer is a mass
spectrometer that has more than one analyser,
usually two, with a collision chamber in
between.

51. TMS allows the screening of a numerous array of
metabolic disorders in a single analytical run:
• Amino Acid Disorders
PKU, MSUD, Tyr, Cit, etc
• Fatty Acid Oxidation Disorders
• Organic Acid Disorders

53. Advantages of TMS as a screening
tool
in NBS
• Sensitive
• Specific
• Accurate Quantitation
• Internal standards: gold standard for accuracy
• High impact
• Multiple Metabolite, Multiple Disease Screening
• Cost effective

54. Sample Collection

56.  




57. Transportation of dried blood
spot specimens.
 every day if possible or twice a week .
 If samples are not being transported the same day,
the cards should be kept in the collection centers in
refrigerators and protected from moisture.

58. What is follow up action if a
screening test is positive?
 On receiving abnormal screening results, the first
action a pediatrician should take is to confirm
whether the child is well and asymptomatic. Any
child who is not well should be urgently assessed
and may need to be admitted to hospital for
support or specific treatment
 Diagnostic test should follow the positive screening
test
 Genetic counseling is also part of this stage,
including the detection of other carriers in the
family, the recurrence risk, and the possibilities for
prenatal diagnosis in couple’s future pregnancies

59. Is it cost effective??
v
s
Lifelong
disability
??

60. Some labs where screening
can be done
Sandor, Hyderabad
http://sandorlifesciences.co.in
Babyshield www.babyshield.com
NIMHANS, Bangalore
Neogen labs www.neogenlabs.com
Sir Gangaram Hospital, Delhi

61. Summary
 Most of affected newborns are look
and act apparently at birth
 By the time symptoms and signs
appear, damage has already started.
 Widow period is available
 Screening will help us in timely
diagnosis.
 Timely diagnosis and specific
treatment can give a normal life to the
child.

62. References
 NNF clinical practical guidelines –
2011
 IJPP- Newborn Metabolic Screening (Vol.17
No.1)
 Oxford monographs - IEM
 Care Of Newborn – Meharban Singh
 Nelson textbook of Pediatrics