The 28 different diagnoses assigned to the individual cases (Table 5) included patients with rare and novel diseases, such as congenital neuronal ceroid lipofuscinosis caused by mutations in the Cathepsin D gene [19], 2-methylbutyrylglycinuria [20] confirmed by mutation analysis (Andresen B, personal communication), and Cockayne syndrome caused by a novel mutation in the CSA gene [21]. This evidence concerns the gene CTSD and Cockayne syndrome.