First PEX11β patient extends spectrum of peroxisomal biogenesis disorder phenotypes.

Among the human PEX genes associated with peroxisome biogenesis disorders, only the PEX11 family genes had not previously been associated with human disease. A new study identifies the first patient with a mutation in PEX11β. The patient presents with symptoms atypical for peroxisome biogenesis disorders. Peroxisomes in cells derived from this patient appear enlarged and undivided, complying with the role of PEX11 proteins in peroxisome proliferation and division. These new findings widen the spectrum of clinical and cellular phenotypes of diseases associated with defective peroxisome formation.