HomeResearchIntramural ResearchResearch Branches at NHGRIMedical Genetics Branch Huizing Lab

Marjan Huizing, Ph.D. Associate Investigator Medical Genetics Branch Head Cell Biology of Metabolic Disorders Unit M.Sc. Wageningen University, Netherlands, 1992 Ph.D. Nijmegen University, Netherlands, 1998 (301) 402-2797 (301) 496-7184 mhuizing@mail.nih.gov Building 10, Room 10C-103 10 Center Drive, MSC 1851 Bethesda, MD 20892-1851 Selected Publications

The Section on Human Biochemical Genetics investigates rare and informative human genetic disorders to understand normal and abnormal intracellular processes. These studies can provide guidance for treatment of specific metabolic defects.

My particular area of interest involves Hermansky-Pudlak syndrome (HPS), a disorder of intracellular formation and trafficking of lysosome-related organelles. Affected patients have defects in their melanosomes (causing albinism), platelet dense bodies (causing bleeding), and lysosomes (perhaps causing granulomatous colitis or a fatal pulmonary fibrosis). We described the characteristics of the various HPS subtypes by examining 120 affected individuals. On the genetic level, our lab has identified the genes causing HPS type 2 and type 3, and we continue to search for new genes causing unique HPS subtypes. On the cellular level, we visualize the vesicular transport defects using different imaging techniques, including live cell imaging. The patients? cells allow us to identify intracellular membrane trafficking pathways, novel protein interactions, and functions of vesicular transport genes, increasing our understanding of lysosomal biogenesis.

Another of my areas of interest is sialic acid metabolism and its disorders, including sialuria (a defect in feedback inhibition of the rate-limiting step in sialic acid synthesis), infantile free sialic acid storage disease (a lysosomal transport disorder of free sialic acid), and hereditary inclusion body myopathy (a defect in the bifunctional enzyme UDP-GlcNAc 2-epimerase/ManNAc kinase, which catalyzes two committed steps in sialic acid biosynthesis). Sialic acid modifications of glycoconjugates expressed at the cell surface are crucial for many biological processes, including cell adhesion and signal transduction.

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Last Updated: June 2004