The behavioural phenotype in velo-cardio-facial syndrome

The concept of a ‘behavioural phenotype’ was initially coined by William Nyhan in a presidential address to the Society of Pediatric Research (Nyhan 1972). In a vivid description of the aggressive self-mutiliation he observed in patients with Lesch–Nyhan syndrome, Nyhan emphasized the role of organic factors in the development of these behaviours and referred to the behavioural phenotype as ‘behaviours which are an integral part of certain...