Study finds gene mutation that turns familiar faces into strangers Premium
The Hindu
According to research published in this month’s issue of the journal Genetics, by researchers led by Ye Rao of Capital Medical University, Beijing, when the MCTP2 gene is mutated, our ability to recognise faces is severely impaired.
A simple joy, often taken for granted, is to unexpectedly run into a friend or a relative at a train station or market. Recognising a familiar face in an unfamiliar context or crowded place gives most of us unalloyed pleasure.
We should give thanks to our MCTP2 gene for this ability. According to research published in this month’s issue of the journal Genetics, by researchers led by Ye Rao of Capital Medical University, Beijing, when this gene is mutated the ability to recognise faces is severely impaired.
Individuals with the misfortune of carrying the mutant gene took much longer than is socially acceptable to recognise people with whom they were expected to be familiar — such as spouses, siblings, and children — while they confused strangers with familiar people.
This disorder is called prosopagnosia, or face blindness. Its prevalence worldwide is estimated to be 1.8-2.9% in the general population. Prosopagnosia is one form of visual agnosia, or inability to identify everyday items just by looking at them.
The MCTP2 gene is thus the first found to be required for a higher form of visual social cognition in humans.
The researchers identified a family of 35 individuals spread across three generations. The members of its eldest generation were all older than 60 years. Nine members of the family had daily problems with recognising faces. They also performed very poorly on a standardised face recognition test. Another nine performed normally in the tests, yet they too had difficulty recognising faces.
The remaining 17 — including nine who married into the family — performed normally in the tests and had no difficulty recognising faces.
