Dr. Frauemdienst-Egger and myself also continued our work on our comprehensive database for inborn errors of metabolism now with more than 1000 diseases www.metagene.de
It is worth trying it to better diagnose patients with unknown metabolic diseases before you start with expensive diagnostic procedures like whole exon sequencing. Beside of metabolites you can enter relevant clinical symptoms of your patient and you get most reliable suggestions of possible inborn errors of metabolism.