Mutations in SPTLC1, encoding serine palmitoyltransferase, long chain base subunit-1, cause hereditary sensory neuropathy type I

Nat Genet. 2001 Mar;27(3):309-12. doi: 10.1038/85879.

Abstract

Hereditary sensory neuropathy type I (HSN1) is the most common hereditary disorder of peripheral sensory neurons. HSN1 is an autosomal dominant progressive degeneration of dorsal root ganglia and motor neurons with onset in the second or third decades. Initial symptoms are sensory loss in the feet followed by distal muscle wasting and weakness. Loss of pain sensation leads to chronic skin ulcers and distal amputations. The HSN1 locus has been mapped to chromosome 9q22.1-22.3 (refs. 3,4). Here we map the gene SPTLC1, encoding serine palmitoyltransferase, long chain base subunit-1, to this locus. Mutation screening revealed 3 different missense mutations resulting in changes to 2 amino acids in all affected members of 11 HSN1 families. We found two mutations to be located in exon 5 (C133Y and C133W) and one mutation to be located in exon 6 of SPTLC1 (V144D). All families showing definite or probable linkage to chromosome 9 had mutations in these two exons. These mutations are associated with increased de novo glucosyl ceramide synthesis in lymphoblast cell lines in affected individuals. Increased de novo ceramide synthesis triggers apoptosis and is associated with massive cell death during neural tube closure, raising the possibility that neural degeneration in HSN1 is due to ceramide-induced apoptotic cell death.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyltransferases / chemistry
  • Acyltransferases / genetics*
  • Amino Acid Sequence
  • Apoptosis / genetics
  • Base Sequence
  • Chromosome Mapping
  • Chromosomes, Human, Pair 9 / genetics
  • DNA Primers / genetics
  • Exons
  • Glucosylceramides / biosynthesis
  • Hereditary Sensory and Autonomic Neuropathies / enzymology*
  • Hereditary Sensory and Autonomic Neuropathies / genetics*
  • Hereditary Sensory and Autonomic Neuropathies / pathology
  • Humans
  • Molecular Sequence Data
  • Mutation*
  • Protein Subunits
  • Sequence Homology, Amino Acid
  • Serine C-Palmitoyltransferase

Substances

  • DNA Primers
  • Glucosylceramides
  • Protein Subunits
  • Acyltransferases
  • SPTLC2 protein, human
  • Serine C-Palmitoyltransferase

Associated data

  • GENBANK/AF286703
  • GENBANK/AF286704
  • GENBANK/AF286705
  • GENBANK/AF286706
  • GENBANK/AF286707
  • GENBANK/AF286708
  • GENBANK/AF286709
  • GENBANK/AF286710
  • GENBANK/AF286711
  • GENBANK/AF286712
  • GENBANK/AF286713
  • GENBANK/AF286714
  • GENBANK/AF286715
  • GENBANK/AF286716
  • GENBANK/AF286717
  • GENBANK/Y08685