• Genetics
• metabolic disorders

In a seminal article in 2007, Ropers presented new perspectives for the elucidation of genetic disorders.1 He states what clinical geneticists have known for years—that Mendelian disorders, and in particular, autosomal recessive disorders, deserve more attention. Online Mendelian Inheritance in Man (OMIM) indicates that there are 1638 autosomal phenotypes for which the molecular basis is unknown. Historically, such disorders have been neglected, both because of their rarity and because of the difficulty in identifying the underlying genes and mutations.

Recently, exome capture and sequencing has been shown to be a feasible approach to identifying disease mutations,2–4 in theory using only a single patient. Thus a systematic programme to discover all of these genes is an appropriate and timely objective.

Those of us working in the area of clinical research often give lip service to the concept that we are working for the direct benefit of patients, when in fact our goals are much more basic. The value of gene discovery for Mendelian disorders is that the results can be used immediately—if not for therapy, then at least for diagnosis, prognosis and genetic counselling. Although it is true that gene discovery often leads to a better understanding of pathogenesis and therapy, our short-term goal should be gene discovery for the sake of better diagnosis and genetic counselling.

In the ‘RaDiCAL’ (Rare Disease Consortium for Autosomal Loci) based at McGill, we concentrate our efforts on putative autosomal recessive diseases and start wherever possible with the …