What Is Genetic Newborn Screening Test and Who Can Opt for It?

July 22, 2021

A newborn screening (NBS) test is done to find out different genetic, developmental, and metabolic conditions in the newborn. With a genetic newborn screening test, a doctor can identify genetic disorders in a newborn, and rectify or control the condition by taking proper steps before the symptoms develop. The test helps both the parents and doctors to diagnose the condition, and take timely measurements to manage, intervene or treat the disease. This will help the baby lead a healthy and happy life.

Is It Necessary to Take Genetic Newborn Screen Tests for All Newborns?

The newborn genetic screening test is necessary for every newborn baby for genetic diseases may not be apparent when a baby is born. Hence, medical science suggests all babies be screened at birth whether their physical appearance is healthy or not.

For instance, a child, who has PKU, will not show any unhealthy signs since the condition may not manifest any symptoms. Nevertheless, a baby with this condition cannot metabolize phenylalanine, which is present in milk and sweeteners, and the accumulation of this substance in the blood may lead to brain damage. More than 70 to 80 per cent of any medical conditions in a baby can be managed when diagnosed immediately after birth, but some genetic health conditions such as sickle cell anaemia cannot be cured completely. However, early detection can save the life of the baby; for this reason, every baby must be screened for genetic disorders.

How Is Genetic Newborn Screening Test Conducted?

The newborn screening test is conducted for every baby within 24-48 hours of the birth. The screening test is performed until the time the baby is 13 days old. It is also possible to find the disorders until the age of 2 through genetic screening. However, it is advisable to have the screening as early as possible.

The blood sample of the baby is collected from the heel of the baby by pricking, and the sample is sent to a laboratory for a biochemical test for screening of several inherited conditions.  The inherited health conditions or genetic disorders are generally transferred to the baby through genes or chromosomes. Normally, the newborn screening tests involve:

  • Blood tests: The blood test is done to find out the health conditions such as phenylketonuria (PKU), methylmalonic acidemia, maple syrup urine disease (MSUD), tyrosinemia, citrullinemia, medium chain acyl CoA dehydrogenase (MCAD) deficiency, and sickle cell anaemia. Furthermore, a blood test is also performed to diagnose hormone problems, haemoglobin issues and other diseases.

Newborn screening

What Is Genetic Disorder?

A human body consists of millions of cells and each cell contains 46 chromosomes or matching pairs of 23 chromosomes, where half of the pairs of 23 chromosomes come from the baby’s father and the other 23 chromosomes from the mother. These chromosomes are responsible for the physical, mental, and biological characteristics of an individual. The genetic material gives instructions to the body for growth and development. When some detrimental changes occur in the DNA, it is termed a genetic disorder. It changes the way the child develops and affects the mental and physical growth and well-being of the child.

The genetic disorder may either be inherited from the parents or may happen for the first time. However, in both cases, it will lead to health problems such as brain damage, physical disability, mental retardation, and so on.

Benefits of Genetic Newborn Screening?

By performing the screening test on the newborns, any observable symptoms are identified and treated.  This test is just diagnostic testing and the follow-up tests are suggested if any condition exists in the baby. The screening test also detects the inborn errors of metabolism owing to natural chemicals produced in the body.

What Kind of Disorders Can Be Identified Through New-Born Screening?

With the screening tests, more than 44 metabolic disorders in newborns can be diagnosed by collecting blood samples. Many of the disorders are caused by chemical imbalances inherited from the parents. Such chemical imbalance will have a strong effect on the newborn within a few days or weeks. Parents who have no previous history and have healthy children without any disorder may have babies born with these disorders. The children born with such disorders may behave completely normally, and appear to be healthy.

Furthermore, the mortality rate of such children is 5 to 10 out of 1000 children, even in developed countries. It is nearly 10 times more than that of the developed countries in India.  The newborn screening test helps detect the disorders and reduce the symptoms through proper treatment, healthy diet and medication.

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