Fight against genetic disorders

In India, which has a population of around 140 crores, genetic disorders are very common. Despite its high prevalence, doctors say these disorders are very under-reported and more awareness is needed.

The prevalence of various genetic diseases in India is not uncommon, given the size of the population and the custom of consanguineous or endogamous marriages. It is estimated that several million people in India are affected by genetic disorders, explained Dr. Vinu Narayan, MD Pediatrics, DNB-Superspecialty Medical Genetics (Chair Gold medal), Medical Genetics Consultant, Manipal Hospital.

“About 5,000 to 8,000 rare diseases are known to date, representing 6 to 8% of the world’s population. About 40% of rare diseases can be attributed to a genetic cause. Genetic disorders commonly seen in our country include birth defects, blood disorders such as thalassemia and sickle cell disease, deafness, muscle disorders such as spinal muscular atrophy, lysosomal storage disorders, cystic fibrosis, hyperplasia congenital adrenal, inborn errors of metabolism, albinism, primary immunodeficiencies and many other categories, he said.

According to Dr. Yogesh Kumar Gupta, head of the pediatric intensive care unit, Fortis HospitalsGenetic abnormalities can be divided into two categories: common genetic abnormalities and rare genetic diseases with an incidence of one in a million.

“Compared to ten years ago, with greater clinical insight and sophisticated equipment, we can now detect an increasing number of genetic abnormalities. Genetic counseling begins when there is a family history of genetic conditions, and with the help of a few tests, we educate the patient on the likelihood of the disorders in their offspring,” said Dr Kumar.

Dr. Narayan added that preventing various genetic disorders can be done on many levels.

During pregnancy, one can take advantage of screening for genetic disorders such as thalassemia, Down syndrome (the most common cause of intellectual disability in children) by simple blood tests in the mother and fetal abnormalities by ultrasound.

“If a genetic disease is confirmed in a family member, genetic counseling for pregnancy and therefore a diagnosis of the fetus in early pregnancy is possible (prenatal diagnosis).

Awareness, prevention, early diagnosis, availability and early initiation of treatment are some of the key elements to reduce the burden of genetic diseases in India,” he said.

Dr. Kumar said genetic abnormalities are generally non-modifiable; however, certain types of stresses and factors can produce chromosomal mutations and deletions, predisposing offspring to the same. “Increasing maternal age, maternal smoking, alcohol abuse, pollution, and exposure to certain heavy metals can also cause chromosomal breaks, resulting in a genetic abnormality in the infant.”

Down syndrome: the most common disorder

Down syndrome (DS) is the most common chromosomal disorder. aneuploidy disordercaused by an extra copy of chromosome 21 that comes mostly from the maternal component, says Dr Sunitha MaheshMedical Director and Senior Consultant, Feto Maternal Medicine, Milann Fertility & Birthing Hospital.

According to her, the impact of this aneuploidy varies with maternal age and the risk increases with maternal age, especially after age 40.

Why some people are born with an extra copy of chromosome 21 despite both parents being healthy remains unknown.

“As there is a risk of aneuploidy at any maternal age, it is essential to offer screening methods to all couples for early detection.

“If a test shows the unborn baby has DS, parents can choose to maintain the pregnancy or have it medically terminated. It is important to raise awareness about this common disorder,” she says.