The Genes Behind ‘Intellectual Disability’
Whether you call it “fate” or “karma” or anything else, certain aspects of our life are totally out of our control. One such aspect is the nature of our genes; these are segments of DNA that are passed down from parents to their children. Apart from being the reason why children share physical attributes with their parents, genes are also the reason why some physical and mental illnesses are passed down from one generation to another. That is why doctors ask for the history of a certain disease in the family, such as cancer or diabetes or heart disease. But certain other traits and disorders can be passed on through genes too.
Recently, in a study, researchers found that certain genes can also be responsible for a disorder known as ‘intellectual disability’. This is not a mental illness, but a disability that lessens the grasping power of the brain, when compared with the commonly accepted average standard of intelligence. People diagnosed with intellectual disability usually have an intelligence quotient below 70 – with the average being between 90 and 110 – and they currently make up around 3% of the world’s population.
Hyperactivity, being impulsive or restless are some behavioural symptoms of intellectual disability; some of the general symptoms include difficulty in thinking and understanding. This disorder hampers the intellectual development of the patient and causes them to have trouble with learning practical skills to cope with day-to-day activities. These people often have difficulty adjusting to a regular routine and need constant supervision to ensure their own safety and that of people around them. While a sizeable part of the society has learnt to care for such people, they are still taunted and ridiculed by some.
The study was conducted over a span of five years, in a collaborative effort across three institutions, namely the University of Maryland School of Medicine in the USA, Radboud University Medical Centre in the Netherlands and the University of Health Sciences in Pakistan. The researchers chose a test group of 121 families in rural Pakistan for this study, a region that has a relatively large number of marriages between cousins and blood relatives.[Source]
More than 15,000 DNA samples were collected during the study, which were then analysed using advanced genetic sequencing. The study identified and categorised 30 genes that were found to demonstrate a high potential for causing intellectual disability and other brain disorders.
The study has the potential to help couples perform DNA screenings and determine if there is a possibility of having a child who could, some day, develop an intellectual disability. While the conservative view may be that such methods are inhumane, the other side of the argument is that it would not be fair for the child to be born with a high chance of mental disability. Not having such an offspring would be the practical path for parents to choose.
In fact, this study is just one example of how scientists are finding new methods of preventing the spread of various diseases and disorders through genetic studies. In a utopian future, parents would be able to ensure that they do not pass on any unhealthy genes to their offspring. It is an interesting future that we are looking at, where medicine, ethics, gene technology and culture are all converging to decide the best course of future for humanity.