Towbin, in his article on minimal brain dysfunction (p 1207) again proposes the hypothesis that all of us have a "touch of mental retardation or cerebral palsy" as a result of minor perinatal brain damage. It is not controversial that a continuum from complete normality to total brain destruction must exist, but current thinking has more and more left the classical etiologies of birth trauma and hypoxia behind as factors to be considered in perinatal minimal brain damage. Their role in producing nervous damage is too well documented to be ignored, but other causes seem to be equally important in this regard.
For example, certain genetically inherited metabolic pecularities are very likely to be responsible for less than optimal brain function. Certain types of phenylalanine-hydroxylase deficiency and hyperphenylalaninemia causing borderline intelligence deficit1 are instances of the many variants of the full-blown biochemical abnormality.
Early malnutrition is also being recognized