Peroxisome biogenesis disorders are generally considered to be severe multisystem disorders, often with a progressive component. However, Ratbi et al, in the recent edition of American Journal of Human Genetics (2015 (97): 535-545) report that Heimler Syndrome, a disorder of hearing loss, abnormal dentition and nails, with or without retinitis pigmentosa, is due to hypomorphic alleles of the peroxisomal genes PEX1 and PEX6. The responsible genes were uncovered using whole exome sequencing in 7 families, and biochemically characterized via functional peroxisome testing of patient derived fibroblasts.
This is an excellent example of the marriage of both molecular and biochemical techiques to prove genetic causation of an inborn error of metabolism.
Hilary Vernon, MD PhD