Face Blindness Is a Hereditary Disorder

Friend or stranger? People with face
blindness can't tell; © Hemera

In the first systematic study of prosopagnosia (PA), researchers led by Ingo Kennerknecht, M.D. of the Institute of Human Genetics at the University of Muenster in Germany, recruited 689 subjects from local secondary schools and a medical school and administered a questionnaire to identify those with suspected PA. They found 17 cases of the disorder, and of the 14 subjects who consented to further interfamilial testing, all of them had at least one first degree relative who also had it.

All of the PA subjects revealed that they used up to three different strategies for overcoming the disorder. In the compensation strategy, subjects attempt to recognise people by other characteristics such as voice, gait, clothing or hair colour. In the explanation strategy, subjects have a ready set of excuses as to why they can't recognise someone, such as being deep in thought or needing new glasses. In the avoidance strategy, subjects try to avoid situations where they might be unable to recognise faces, such as large functions or crowded places.

Because of the compensation strategies that those with PA learn to utilise at an early age, many of them do not realise that it is an actual disorder or even realise that other members of their family have it. "This could explain why this kind of cognitive impairment is largely unknown to lay persons or even to physicians other than neurologists and psychiatrists," the authors state, adding that there are no established diagnostic tools for PA. Furthermore, PA is one of the few cognitive functions or dysfunctions that has only one symptom and is inherited, the authors note.

MEDICA.de; Source: John Wiley & Sons, Inc.