Indian researchers, who have been studying three generations of a family in Maharashtra, have stumbled upon a cluster of genes whose aberrations may give rise to dyslexia, a learning disability that affects one in 10 persons in the world.

Strong correlation The scientists, led by Subrata Sinha and Nandini C Singh of the Manesar-based National Brain Research Centre (NBRC), found a strong correlation between certain variations in the gene cluster called protocadherin gamma and dyslexia.

“What is significant about the study is that this gene’s association with dyslexia was never reported in the past,” said Singh, who along with Sinha, is the corresponding author of the paper, which appeared in the journal, EBioMedicine .

“There variations were present in the members of the family with the disability as opposed to those with normal reading abilities. More importantly, these variations are inherited as a single block,” said Sinha.

The scientists, however, were quick to point out that this was just a single family study, not a population-based study.

Global trend World over, a number of genes are known to be associated with dyslexia inheritance. However, none of these genetic associations is able to account for more than a small proportion of the disability.

But there seems to be strong correlation between defects in the protocadherin G gene and learning.

“We found the problem of dyslexia in many members of the family across all three generations. If these genetic variants were present in one family member, the chances of he or she getting dyslexia was found to be very strong,” Singh told BusinessLine.

Interestingly, the gene seems to have evolutionary significance. Seven of the 17 dyslexia associated variations of protocardherin G gene were present in most of the primate species, including gorillas, chimpanzees and bonobos. Further, six of them were found to be present in Neanderthals, as shown by a recently-sequenced Neanderthal genome, said Sinha.

Among others who participated in the study were researchers from Institute of Genomics and Integrative Biology, in New Delhi, and Regional Centre for Biotechnology, Faridabad.

Understanding genetic underpinnings of dyslexia is important because studies have shown that early intervention can help improve the condition considerably, said Singh. “Many people want us to share the information about their children’s genetic preponderance to the disability so that early intervention can be made available to them,” she said.

According to Singh, dyslexia-affected individuals are perfect, except in their ability to read and write. Some of them are highly intelligent otherwise, she said. Most of these dyslexics may take double the time to read and comprehend than normal people.

Singh said her team was trying to develop dyslexia-screening tools in different Indian languages as they are currently available in English. Similarly, she has been trying to create awareness among school teachers about the need for having multi-sensory approach in teaching.

“A dyslexic person may have difficulty in reading and understanding, say three pages of matter given to him, but he or she can easily comprehend it if the same thing is graphically represented,” she said.