Peter Nürnberg and an international team of scientists and clinicians discoverd the causes for a rare genetic disorder called, cblF combined homocystinuria and methylmalonic aciduria. Patients with this disease are hindered to convert the essential Vitamin B(12) (cobalamin) to cofactors. The international team succeeded in identifying LMBRD1 as the gene underlying the cbIF defect of cobalamin metabolism and suggests that LMBD1 is a lysosomal membrane exporter for cobalamin.