Written by 29 June, 2015 1:12 am Category Academic Articles Archives, Archives Articles, Invited Articles.

Dr. Saurabh Dani

Member,
The Mumbai Obstetric and Gynaecological Society

What is Newborn Screening (NBS) Test?

Newborn Screening (NBS) Test is done on Newborn babies to detect certain Treatable Metabolic disorders. These disorders are caused by the accumulation of chemicals produced naturally in the body to abnormally high levels.

These Disorders are present in the baby since birth and are hence termed as Inborn Errors of Metabolism.

This test is usually performed when your baby is 24-72 hrs old. The aim of this test is to detect the metabolic disorder as soon as possible after birth (NOT POSSIBLE TO DETECT IT BEFORE BIRTH) so as to make available maximum treatment options and thus achieve a healthy future for the child.

toxic

Why should a baby do Newborn screening?

Only if we detect the presence of an IEM then can we initiate treatment. And the only way presently to detect the presence of an IEM before the onset of symptoms is by NBS.

If we wait for the symptoms to appear then it may become too late and the child could face its consequences which could be Life threatening in some while others may slow down physical development or cause mental retardation or other problems.

When we do detect the problem what can be done?

Logically there are just two options:-

  1. Create the absent enzyme – PRESENTLY NOT POSSIBLE
  2. Avoid/Restrict consuming “A” (As explained in the above figure)

INCIDENCE OF IEM’s (GOA SCREENING PROGRAM)

Over 400,000 babies (or about 1.5%) born in India each year are affected by a metabolic disorder (Inborn Errors of Metabolism (IEM) – An Indian Perspective by Dr. N. B. Kumta) and many of these babies could have lead a normal healthy life if these disorders were detected and treated early. The primary benefit of the screening program is that by identifying and treating disorders before symptoms appear, many affected babies can lead normal healthy lives into adulthood and be productive citizens of the state. NBS is the norm in most Western countries with the United States making it mandatory in all 50 states.

The incidence rate of these disorders in India is virtually unknown but the incidence is believed to be much higher than the world incidence, due to the high levels of consanguinity. In the ‘Heal to Heal’ Newborn Screening program in Goa under the auspices of the State Government, approximately 1 in every 200 babies is diagnosed with a metabolic disorder. While high, this statistic may well be representative of the true incidence rate for these disorders across India. Since June 2008, Goa state Government has been screening all newborns born in Goa government healthcare facilities for 50+ disorders. In the first 12 months of Goa’s ‘Heel to Heal’ Newborn Screening program we have gained astonishing insight into the incidence of these disorders in India.

1st & 2nd Year Goa Data (103 Cases)

table1

How is the Test Performed?

The only internationally accepted method of NBS is by Dried Blood Spot (DBS). The first step is to make a small prick on your baby’s heel (commonly known as a “heelstick”). A few drops of blood from the baby’s heel are then placed on a special type of filter paper.

leg

The paper is allowed to dry and is then sent to a newborn screening laboratory where several different tests are performed.

Which Tests are performed?
The list of test that should be performed is based on American College of Medical Genetics (ACMG) criteria:

a.   Core Panel or High scoring: Those Disorders that can be well detected and Effective Treatment is available.
b.   Secondary Panel or Moderately scoring: Those Disorders that part of the differential diagnosis Core Panel.
c.   Not Appropriate or Low scoring: These are those Disorders that require further scientific evidence to be included into the first 2 categories and hence are not intended to be included for newborn screening at this time.

panel

How to get the test done and costs involved.

A Parent/Doctor needs to get in touch with the laboratory that specializes in performing these tests. The laboratory will provide the filter paper on which the blood needs to be collected and sent to the Newborn Screening Laboratory. The approximate cost for screening 51 Disorders is between Rs4500-Rs5,000 in India.