This document discusses neonatal G6PD deficiency, including its epidemiology, pathogenesis, clinical presentation, diagnosis, and management. It notes that G6PD deficiency is one of the most common enzymopathies worldwide and an important cause of neonatal jaundice. The deficiency results in impaired antioxidant defense in red blood cells and can lead to hemolysis when exposed to oxidative stress. Timely diagnosis and avoiding triggering factors are important to prevent severe complications like kernicterus. Newborn screening programs have helped identify at-risk infants.

1. NEONATAL G-6PD
DEFICIENCY
Murtaza Kamal
MBBS, MD, DNB
Division of Neonatology
Department of Pediatrics
Safdarjung Hospital & VMMC, New Delhi
DOP- 04/05/2016

2. Overview
 Neonatal Hyperbilirubemia
 Why are neonates prone to it
 Pathological hyperbilirubemia
 Approach to neonatal hyperbilirubemia
 G6PD & its deficiency
 What is it and its deficiency
 Epidemiology, genetics and pathogenesis
 Clinical presentation, diagnosis and
management
 Neonatal screening program

3. A common, mostly benign
problem
60% terms, 80% preterms
Neonatal Hyperbilirubemia

4. Why neonates are prone to
hyperbilirubemia?
1. Increased bilirubin production
Decrease RBC survival, Increased mechanical fragility, More
prone to oxidant damage
2. Increased enterohepatic circulation
High beta- glucuronidase, Decreased intestinal bacteria and
motility
3. Defective uptake of bilirubin from plasma
Decreased ligandin
4. Immaturity of liver
Defective conjugation, Decreased hepatic excretion

5. When does this turn
pathological?
 Onset in first 24 hours of life
 Rate of rise of serum bilirubin
>0.2mg/dl/hr
 Jaundice requiring phototherapy
 Jaundice staining palms/soles
 Persistence beyond 8 (term) and 14 days
(preterms)

6. How to approach a case of
NNJ?
Increased direct bilirubin
Increased indirect bilirubin
Sepsis
Intrauterine infections Coomb’s test +ve Coomb’s test -ve
Bile duct paucity Isoimmunisation
Biliary atresia Rh, ABO, Mi BG
Choledochal cyst
Tyrosenemia etc Hemoglobin
Jaundice in a neonate
Serum bilirubin

7. Hemoglobin
Normal/ Low High (polycythemia)
Twin-twin transfusion
Reticulocyte count Maternal-fetal transfusion
Delayed cord clamping
Increased SGA babies
Red cell morphology
Characteristic Nonspecific Normal
Spherocytosis G6PD defi.G6PD defi. Enclosed hemorrhage
Elliptocytosis PK defi. Increased E-H circu.
Stomatocytosis Inadequate calorie intake
Fragmented cells Neonatal asphyxia

8. Approach (cont…)
Normal red cell morphology +
Increased/ normal reticulocyte count
Prolonged hyperbilirubemia
Gilbert syndrome
Down syndrome
Hypothyrodism
Crigler-Najjar syndrome
Nelson’s Textbook of Pediatrics- 20th
Edition

9. When to suspect hemolysis in
a neonate?
 Clinical features: Jaundice, anemia,
hepatosplenomegaly
 Laboratory evidence : Peripheral
smear showing evidence of hemolysis,
Indirect hyperbilirubemia, Increase in
reticulocyte count, DCT positivity

10. Causes of hemolysis
Intracorpuscular defects:
 RBC membrane defects
 Hereditary spherocytosis,
elliptocytosis,stomatocytosis,
pyknocytosis
 RBC enzyme abnormalities
 G6PD deficiency, pyruvate
kinase deficiency
 Hemoglobinopathies
 Alpha thalassemia
Extracorpuscular defects:
• Immune mediated
• Rh isoimmunization, ABO or Mi
BG incompatibility
• Macro/microangiopathic
• Large vessel thrombi,
Cavernous hemangioma,
Renal artery stenosis
• Infections
• Sepsis, TORCH ,Parvovirus
B19 (anemia due to RBC
aplasia) ,Malaria
• Drugs- ibuprofen, penicillin,
• Galactosemia
• Acidosis- metabolic/ respiratory

11. Glucose-6-Phosphate
Dehydrogenase (G6PD)
and its deficiency

12. What is G6PD?
 A house keeping enzyme critical in
redox metabolism of all aerobic cells
 Role in RBCs very critical- The only
source of reduced NADP
 NADPH directly or via reduced
glutathione defends RBCs against
oxidative stress

13. G6PD Deficiency
 The most prevalent RBC enzymes
deficiency
 400 million people are affected worldwide
(4.9%) [1]
 Coincides with the geographic distribution of
endemic malaria
1.Frank JE. Diagnosis and management of G6PD deficiency. Am Fam Physician 2005;72:1277-82

14. Distribution
Highest prevalence in Sub-Saharan Africa, Middle East, Mediterranean
Europe, and Southeast Asia

15. The Indian scenario…
 Incidence: 2-27%[2]
 MC variant: G6PD Mediterranean
 Mostly in:[3]
 Vataliya prajapatis of north india
 Parsis
 Punjab, Kerala, Andhra Pradesh
[2]. Mohanti D, Mukherjee MB, Colah RB. G6PD deficiency in India. Indian J Pediar 2004;71:525-9.
[3]. Pao M, Kulkarni A, Gupta V, Kaul S, Balan S. Neonatal screening for G6PD deficiency. Indian J Pediatr 2005;72:835-7.

16. Genetics
 Gene located on X-chromosome (sex
linked recessive)
 Disease fully expressed in hemizygous
males and homozygous females
 Variable intermediate expression by
heterozygous females

17. Clinical implications of molecular
basis of G6PD deficiency
 A house keeping gene- Deletions of G6PD genes
incompatible with life (hydeletions); death in utero
 Point mutations:
 Sporadic:
 No geographical specificity
 No causal relationship with malaria selection
 Manifests with CNSHA
 Polymorphic:
 Resulted from malaria selection
 Correlate with specific geographical areas

18. WHO Classification of G6PD
variants
WHO Class Level of
deficiency
Enzyme activity Severity of
hemolysis
1 Severe <10% CNSHA
2 Severe <10% Intermittent
hemolysis
3 Moderate 10-60% Intermittent
hemolysis with
stressors
4 Mild to none 60-150% No hemolysis
5 None >150% No hemolysis

19. Pathogenesis
 As red cells age, G6PD activity falls rapidly and
prematurely
 So, diminished NADPH/NADP and GSH/GSSG
ratios
 Impaired elimination of oxidants (H202)
 Oxidation of hemoglobin and sulfhydrl groups in
membrane

20. Pathogenesis (cont.)
 Red cell integrity impaired (on
exposure to oxidant drugs/ oxidant
response to infections and chemicals)
 Oxidized hemoglobin precipitates to
form Heinz bodies, plucked out of the
cell leading to hemolysis and bite cell
blister cell morphology

21. Pathogenesis (cont…)

22. When to suspect G6PD
deficiency in a neonate?
 Development of hyperbilirubemia within
24 hours of life
 History of neonatal jaundice in family
members of siblings
 Have bilirubin level >95th
percentile
 Have evidence of hemolysis with
negative DCT

23. Clinical Presentation
 A. Neonatal hyperbilirubemia
 B. Drug induced hemolysis
 C. Favism
 D. Chronic non-spherocytic hemolytic
anemia

24. Neonatal hyperbilirubemia in
G6PD deficient neonates
 Severe manifestation of G6PD deficiency
and source of potential morbidity from
kernicterus
 Probably starts in utero, but clinical problem
becomes apparent on day 2/3 of life
 10-50% deficient neonates affected
 Indian data: 13.3% of all jaundiced neonates
(and out of these 16% female neonates) [4]
[4]. Seema Kapoor et al. Newborn screening for G6PD deficiency; A 2-year data from north India. Indian J
Public Health.2015.

25. Neonatal hyperbilirubemia in
G6PD deficient neonates(cont.)
 Mechanisms:
 Reduced glucuronidation of bilirubin due to
defective G6PD activity in hepatocytes
 Hemolysis triggered on exposure to oxidants like
naphthalene balls
 Co-inheritance of UDP-glucuronyltransferase 1
deficiency of Gilbert syndrome
 Pregnant women ingesting oxidant drugs,
transmitting it to her G6PD deficient fetus

26. Drugs carrying risk of
hemolysis in G6PD deficients
Drugs Definite risk Possible risk Doubtful risk
Antimalarials Primaquine
Dapsone
Chloroquine Quinine
Sulfonamides Sulphametoxazole Sulfasalizine
Sulfadimadine
Sulfisoxazole
Sulfadiazine
Antibiotics Nitrofurantoim
Nalidixic acid
Cotrimoxazole
Niridazole
Ciprofloxacin
Norfloxacin
Chloramphenicol
P-Aminosalicylic
acid
Antipyretics/
Analgesics
Acetanilide Aspirin(>3g/d) Aspirin(<3g/d)
Acetaminophen
Others NaphthaleneNaphthalene
Methylene blue
Vit K analogues
Ascorbic acid >1g
Rasburicase
Doxorubicin
Probenecid
Harrison’s Textbook of Internal Medicine-19th
edition

27. Laboratory diagnosis of G6PD
deficiency
Screening/ Qualitative tests:
Ultraviolet spot test
Methaemoglobin reduction test
Brilliant cresyl blue decolorisation test
Definitive/ Quantitative test:
Spectrophotometric analysis
Molecular diagnostic testing and DNA
analysis

28. Methord used in our case…
 Dried blood spots collected by heel prick on blood
sample collection card (Whatman 903 s & s, GE
Healthcare)
 Analysis done by fluroimmunoassey using Flurometer
 Principal: DBS allowed to react with substrate (G6P
+NADP) for 30 mins at ambient temperature
 Fluorescent measured using excitation wavelength of
355nm and emission wavelength of 460nm
 Values <16U/dl considered deficient

29. Importance of quantitative
tests
Situation 1:
 During a hemolytic attack, old RBCs destroyed, therefore
surviving young RBCs and reticulocytes have relatively
higher G6PD
 Screening test can be false normal
Situation 2:
Heterozygous females diagnosis
 Probability of clinically significant hemolysis in
heterozygote roughly correlates with proportion of G6PD
deficient cells
 Hence, if a normal level of G6PD activity is found in a
heterozygotye, she is unlikely to be at risk of G6PD related
hemolysis

30. Prevention & Treatment
 Phototherapy and exchange transfusion for
neonatal jaundice
 Stop the offending drug
 Blood transfusion if severe anemia
 Folic acid supplementation

31. Initiated back in 1963…
Newborn Screening
Programme

32. Wilson & Juegner 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 population.

33. Wilson & Juegner criteria
for disease screening (cont.)
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

34. Diseases for which neonatal
screening is being done
 Glucose 6 phosphate dehydrogenase
deficiency (G6PD levels)
 Congenital hypothyroidism (TSH)
 Congenital adrenal hyperplasia (17OHP)
 Galactosemia
 Biotinidase deficiency

35. Take home message
 Answer to neonatal hyperbilirubemia is not just photo-
therapy and exchange transfusion, Do investigate for its
cause
 G6PD deficiency is not very uncommon condition as
approximately 5% of world’s population is affected, so
should be kept in mind
 In view of a high gene frequency for a disorder that is
manageable with just elimination of a few drugs and
foodstuffs, newborn screening is the need of the hour