COVER STORY

When genes don't fit

The treatment of rare genetic disorders is extremely difficult and expensive

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Aarav Sharma is a cheerful little boy who loves to play chess with his parents. When I met the six-year-old, at his home in suburban Mumbai, he was playing with Lego blocks, creating and recreating. He told me that he loved to draw and paint with his new set of crayons and felt-tip pens. In his school uniform, a white tee with a colourful bumblebee print, and red short pants, he was like any other boy of his age, except that his body was in crutch-braces from neck to toe. He used them while standing, walking, and even as he would sit; each time, every time. “It stays with him throughout, and helps him support and balance his body so that he doesn't fall,” says his soft-spoken mother, Alpana Sharma.

Aarav suffers from spinal muscular atrophy (SMA) type 2, a rare genetic and progressively degenerative disease. The worst fears of his parents are that in a few years, the disease might affect their son's spinal motor nerve cells, and rob him off his ability to not just walk, but also to eat on his own and even breathe. SMA mainly develops in children between ages 6 to12 months, and the affected children, even though they can sit without support until their teens, cannot stand or walk unaided. As Aarav undergoes his numerous therapies, including the chest nebulisation therapy twice a day, Alpana looks at me and says, “I must have asked the universe a million times, why us? We haven't done anything wrong.”

“Nobody is to blame for these diseases, especially since these disorders are essentially the result of mutations in certain specific genes, and the occurrence of these gene mutations is an event beyond human control,” says Dr Mamta Murunjan, clinical geneticist, KEM Hospital and Hinduja Hospital, Mumbai. “SMA is the result of a mutation of the Survival Motor Neuron Gene 1 (SMN1). A gene mutation is a permanent alteration in the DNA sequence that makes up the gene, such that the sequence differs from what is commonly found in normal people. Each of the parents usually carries one mutated copy of the gene, and are referred to as carriers. When two carriers have a child, there is a chance of the child either having SMA or of being a carrier. Each child has a 25 per cent chance to have the condition, 50 per cent chance to be a carrier like each of the parents, and 25 per cent chance to not have the condition or be a carrier,” she explains.

SMA affects 1 in 40 children in India. It is one of the 7,000 plus rare diseases existing in the world, of which a majority are genetic in nature. Prasanna Kumar Shirol, cofounder and executive director of Organisation of Rare Diseases in India (ORDI) says that children are the biggest casualty of rare genetic disorders, which can be divided into seven. The most common are blood disorders, immunodeficiency disorders, bleeding disorders, lysosomal storage disorders, neuromuscular disorders, skeletal dysplasia and small molecule diseases.

Nobody is to blame for these diseases, especially since these disorders are essentially the result of mutations in certain specific genes, and the occurrence of these gene mutations is an event beyond human control. - Dr Mamta Murunjan clinical geneticist, KEM Hospital and Hinduja Hospital, Mumbai.

Often, a family has no idea about members being carriers until a child is born with a recessive disorder. For instance, it was after the birth of their second child, Aarya, that Sheetal Bhatkar and her husband, Vikrant Bhatkar, realised that they were both carriers of Neimann Pick type C, a neurodegenerative disease. It is one among a group of lysosomal storage diseases (LSDs) that affect metabolism and is caused by a genetic mutation. “It is the rarest of rare lysosomal storage disorders, known to afflict one in 10 lakh children. In fact, of the 600 children with LSDs registered at the LSD Support Society, Aarya was the only one who was afflicted by Neimann Pick type C,” says Sheetal, 40, who lost her seven-year-old son to the disease three years ago.

“He was born a normal baby with a decent weight and was developing normally like any other child till he was 15 months, after which his health began to deteriorate,” she recalls. “He then started showing symptoms like development delays, movement problems, seizures and spleen enlargement. About a year later, he was diagnosed with the disease. We were told that there was no cure for it and that it is a terminal illness.” The average life-span of a patient with Neimann Pick type C is 20 years.

But after losing their son, the couple wanted to confirm that their 15-year-old daughter Prachiti didn't have it, especially since Neimann Pick Type C is known to hit a child at any age. Upon testing her DNA, it was revealed that Prachiti was a carrier of the affected gene from her father, but a healthy gene from her mother negated it, and made it possible for her to lead a normal life.

The LSDs are a group of 45 rare disorders, of which diseases such as Pompe, Gaucher, Fabry, mucopolysaccharidosis (MPS) and Neimann Pick type C are found in India. “As of now, Neimann Pick type C has no medicine that can cure it, other than the one that helps in controlling the symptoms. Drugs are under trials,” says Hrishikesh Kumar, head of the department of neurology at the Institute of Neurosciences in Kolkata.

Dr Ratna Puri, senior consultant and chairperson at the Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital, Delhi, says that the treatment options of rare genetic disorders are extremely expensive. “I only know of one patient in the world, from Indonesia, who could afford it, because they were the owners of an oil distribution company. These drugs are either supported by the state, or by insurance. In the UK, it comes under National Health Sservice, in Australia it comes under government funding, and in the US it is covered by insurance,” said Dr Puri. In the case of an LSD, it costs Rs 30 lakh for a 10ml vial for one year. It is a life-long therapy and as the weight of the patient increases, so will the cost. Prasanna, whose 19-year-old daughter has been on ventilator for the past ten years and in coma the last six months, says it took seven years to get the diagnosis. “The treatment for LSD cost around Rs 1.5 crore per year now that she is 30kg. When she will be 40kg it will rise to Rs 1.72 crore, and at 50kg, Rs 3 crore and so on.... It all depends on her weight.”

The cost of treatment for rare diseases is exorbitant because the number of patients is few, and owing to the years of research that go in. To treat Pompe, which is also an LSD caused by the accumulation of glycogen in lysosomes, one vial of 50mg costs $700 (Rs 46,802). Recently the government announced the National Rare Disease policy, by which it has allocated a Rs 100 crore corpus, and has assured that whatever money is required for the treatment will be raised from various sources.

Sensing a need among parents to know what treatment options to look for and how to go about caring for their child while dealing with anxiety, depression and frustration, a number of patient groups have been set up. These act as anchors and help centres for those in similar situations. Sangeeta Barde, cofounder ORDI, says “We all get together, and help families get access to expensive drugs, while at the same time we make them aware of what others in similar situations are doing. That helps.”