1. Mutations in TMEM76* cause mucopolysaccharidosis IIIC (Sanfilippo C syndrome).
- Author
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Hrebícek M, Mrázová L, Seyrantepe V, Durand S, Roslin NM, Nosková L, Hartmannová H, Ivánek R, Cízkova A, Poupetová H, Sikora J, Urinovská J, Stranecký V, Zeman J, Lepage P, Roquis D, Verner A, Ausseil J, Beesley CE, Maire I, Poorthuis BJ, van de Kamp J, van Diggelen OP, Wevers RA, Hudson TJ, Fujiwara TM, Majewski J, Morgan K, Kmoch S, and Pshezhetsky AV
- Subjects
- Acetyltransferases chemistry, Acetyltransferases metabolism, Amino Acid Sequence, Animals, Base Sequence, Cell Line, Chromosome Mapping, Chromosomes, Human, Pair 8 genetics, Cloning, Molecular, DNA Mutational Analysis, DNA, Complementary genetics, Exons, Female, Gene Expression, Humans, Male, Mice, Molecular Sequence Data, Pedigree, Polymerase Chain Reaction, Recombinant Fusion Proteins genetics, Recombinant Fusion Proteins metabolism, Sequence Homology, Amino Acid, Transfection, Acetyltransferases genetics, Mucopolysaccharidosis III enzymology, Mucopolysaccharidosis III genetics, Mutation
- Abstract
Mucopolysaccharidosis IIIC (MPS IIIC, or Sanfilippo C syndrome) is a lysosomal storage disorder caused by the inherited deficiency of the lysosomal membrane enzyme acetyl-coenzyme A: alpha -glucosaminide N-acetyltransferase (N-acetyltransferase), which leads to impaired degradation of heparan sulfate. We report the narrowing of the candidate region to a 2.6-cM interval between D8S1051 and D8S1831 and the identification of the transmembrane protein 76 gene (TMEM76), which encodes a 73-kDa protein with predicted multiple transmembrane domains and glycosylation sites, as the gene that causes MPS IIIC when it is mutated. Four nonsense mutations, 3 frameshift mutations due to deletions or a duplication, 6 splice-site mutations, and 14 missense mutations were identified among 30 probands with MPS IIIC. Functional expression of human TMEM76 and the mouse ortholog demonstrates that it is the gene that encodes the lysosomal N-acetyltransferase and suggests that this enzyme belongs to a new structural class of proteins that transport the activated acetyl residues across the cell membrane.
- Published
- 2006
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