tokens: The second patient , a boy of Maltese extraction who was found to have bilateral lamellar cataracts at the age of 4 years , was identified as G6PD deficient only as a result of a survey of children of Mediterranean origin with unexplained cataract formation ; he has approximately 15 % of normal enzyme activity , with another unique combination of biochemical characteristics which has led to its designation as Gd ( - ) Camperdown .