Newborn Screening ( A BASIC RIGHT OF NEWBORN)
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Newborn Screening

   

Clinical observation and Physical examination Specialized tests (recommended)

   • Audiological assessment for hearing: ABR (1st test: Full term/at least 34 Gest.wk:if fail, repeat at 3 month age)
   • Examination of Eyes : Ophthalmoscopy
   • Assessment of Heart Disease : Echocardiogram (if murmur present)  
       

Laboratoy test (advised)

 

Preferably be done after 48 hours

   • Neonatal TSH (CHT)  
   • G-6-PD (Enzyme deficiency)  

At 6 month of age

   • Hb electrophoresis (Thalassemia, HbE)
     
     

Optional (done on request)

 
   • Plenylamine (Phenylketomuria)  
   • Galactose
   • 17a-hydroxyprogesterone (Congenital Adrenal Hyperplasia)
   • Biotinidase deficiency
   • Medium chain acyl CoA deficiency
   • Immnoreative trypsinogen (Cystic Fibrosis)
Note : TSH, G-6-PD and Hb electrophoresis are diagonostic. However, optional tests are available as screening or diagnostic tests (test charge will vary accordingly)
       
       
Newborn Screening    
  Newborn Screening is the process of testing newborn babies for treatable genetic, endocrinologic, metabolic and hermatologic diseases.1,2  According to WHO figures, about 140 million children are born every year. 5 million children die in the first month of life in developing countries and 4 million children are born with some congenital anomaly. Thousands of children die of no definable cause e.g. sudden Infant Disease Syndrome (SIDS). Almost 27-30% of these babies are now proved to be having some inborn error of metabolism. The socio-economic burden makes couple desire 1-2 children, free from handicaps.

In Asia, most countries with notable exception of South-Asian countries, have national Neonatal Screening Program for at least 2-3 diseases common in respective countries. In Western countries, according to prevalence, phenylketomuria. Cystic fibrosis, Galactosemia, Congenital adrenal hyperplasia, MCAD are among the listed disorders (Which varies between countries) for newborn screening. However, in Bangladesh, these disorders are probably rare (there is a lack of statistical data available), and considering constrains in health care, presently, we would like to include the following, disorders for neonatal screening.

Congenital hypothyroidism
G-6-PD deficiency
Thalassemia and Hb E
       
       
Purpose of Newborn Screening    
   • Congenital and heritable disorders which can be missed clinical at birth
   • Disorders evertually cause serere illness, or death if not treated early in life
   • Disorders inherited as trait and poses risks of spreading the disease in general population
   • Treatment or intervention that makes a difference if the disease is detected early
   • A high enough prevalence (i.e. >1/1.000-50,000) depending on cost-benefit and resource availability
       
       
If Untreated, Disorders can result in :    
   • Growth and Mental retardation
   • Neurological deficits (deafness, blidness, cerebral palsy, seizures, coma)
   • Milestone development delay
   • Behavioural/emotional problems
  Note : The test parameters may be expanded when more data of such disorders in our neonates will be availble in future.
       
       
Physical/ Anatomical Screening    
   • Congenital heart disease
   • Other congenital malformations including congenital dislocation of the hip, cryptorchilism and undescended tests
   • Congenital cataracts and other media opacities
   • Anatomical abnormalities
   • Hecaring screening at birth, especially for babies spent >48 hours n NICU or SCBU the test should be done after 34 weeks (gestational age) by automated auditory brainstem response (AABR)3. In case of failed or equivocal result, retest at 3 month of age
       
       
Metabolic/Endocrine/Genetic Screening    
Congenital hypothyroidism(1:3000)4
Infants born with congenital bypothyrodism may show no effects, or may display mild effects that aften go unrecognized as a problem: escessive sleeping, reduced interest in nursing, poor muscle tone, low or hoarse cry, infrequent bowel movements, exaggerated jaundice, and low body temperature. If untreated for several months after birth, severe congenital hypothyroidism can lead to growth failure and permanent mental retardation. The goal of newborn screening programs is to detect and start treatment within the first 1-2 weeks of life.

Diagosis based on measurement of TSH or thyroxine (T4) on the second or third day of life (TSH is high, or the T4 low).
       
Thalassaemia & Hb E (Bangladesh: 6.2% (Hb E trait), 4.1%(-Thal trait), 3,00,000/y (E Thal}]5
Thalassamia is an autosomal recessive disorder. While a Thalassamia Major is incompatible with intrauterine life, ß-Thalassamia Major results in life threatening anemia and requires blood transfusions every 4-6 weeks and iron chelation to prevent further illness. Hemoglobin E (Hb E) is a single point mutant in the ß chain of hemoglobin. This is an asymptomatic mutation, except in combination with certain Thalassamia mutations where it provides an increased resistance to malaria (P. falciparum). Hemoglobin E is most prevent in Southeast Asia (Thailand, Indonesia, Bangladesh and Northeast India), where in certain areas carrier rates reach 60% of the population. Half of the patients with HbE/ ß-Thalassamia have a severe phenotype consistent with ß-Thalassamia major. Therefore all partners of known ß-Thalassamia carriers should be screened for HbE irrespective of MCV and MCH to predict for the risk of HbE/ ß-Thalassamia. This is achievable by Hb Chromatography.
       
G6PD deficiency(Incidence is high i.e. >1% in South and South-East Asia6
It's an X-Linked recessive disorder of hemolysis when exposed to drugs( primaquine, sulpha), fava bean ingestion, infection (viral hepaties, typhoid) affercting male while females are carrier. Clinically, it is important to screen newborns for G6PD deficiency and followed such infant more carefully for rising bilirubin at end of first week which cause kernicterus. With the prompt institution of phototherapy or oral Phenobarbital, much of the sever jaundice reqiring exchange transfusion can be averted.
       
       
High risk groups    
Critically ill newborns
Famillier with history of
   • Previous child with mental retardation or Cerebral palsy or congenital anomaly
   • Past history of recurrent abortions
   • History of sudden infant death in previous sib.
   • Mother with significantly low intelligence and microcephaly
   • Family history of haemoglobinopathy
   • Significant degree of consanguinity
       
       
Recommendations    
   • Considering the reported prevalence in Bangladesh, TSH, G-6-PD and Hb profile may be initiated
   • Neonatal screening for PKU, galactosaemia, profound biotinidase deficiency, MCAD deficiency and CAH would be justified on the evidence
   • Tandem MS for newborn screening for PKU, MCAD deficiency and GA1 should be further evaluated by primary research and evidence dose not support evaluation of other inborn errors of metabolism
       
       
References    
   1 Tarini BA(2007). "The current revolation in newborn screening: new technology, old controversies". Archives of pediatrics & adolescent medicine 161(8):767-72.
   2 Kayton A(2007). "Newborn screening: a literature review". Neonata network: NN 26(2):85-95
   3 NHS Newborn Hearing Screening Program
   4 OM1M: Hypothyroidism, congenital, non-goitrous: Online Mendelian Inheritance in Man.
   5 Hemoglobinopathis and Thalassemias [http://web2.airmail.net/utman/hemoglobinopathy/hemoglobinopathy.html]
   6 Kishor Khodke et al, Incidence of G6PD Deficiency in OPD Cases in a Hospital Journal, Indian Academy of Clinical Medicine Vol.2 No. 4:2001