Combined loss of LAP1B and LAP1C results in an early onset multisystemic nuclear envelopathy

Nat Commun. 2019 Feb 5;10(1):605. doi: 10.1038/s41467-019-08493-7.


Nuclear envelopathies comprise a heterogeneous group of diseases caused by mutations in genes encoding nuclear envelope proteins. Mutations affecting lamina-associated polypeptide 1 (LAP1) result in two discrete phenotypes of muscular dystrophy and progressive dystonia with cerebellar atrophy. We report 7 patients presenting at birth with severe progressive neurological impairment, bilateral cataract, growth retardation and early lethality. All the patients are homozygous for a nonsense mutation in the TOR1AIP1 gene resulting in the loss of both protein isoforms LAP1B and LAP1C. Patient-derived fibroblasts exhibit changes in nuclear envelope morphology and large nuclear-spanning channels containing trapped cytoplasmic organelles. Decreased and inefficient cellular motility is also observed in these fibroblasts. Our study describes the complete absence of both major human LAP1 isoforms, underscoring their crucial role in early development and organogenesis. LAP1-associated defects may thus comprise a broad clinical spectrum depending on the availability of both isoforms in the nuclear envelope throughout life.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abnormalities, Multiple / genetics*
  • Abnormalities, Multiple / metabolism
  • Base Sequence
  • Child
  • Child, Preschool
  • Cytoskeletal Proteins
  • DNA Mutational Analysis
  • Fatal Outcome
  • Female
  • Genetic Predisposition to Disease / genetics*
  • Humans
  • Male
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism
  • Microscopy, Electron, Transmission
  • Mutation*
  • Nuclear Envelope / genetics*
  • Nuclear Envelope / metabolism
  • Nuclear Envelope / ultrastructure
  • Nuclear Proteins / genetics*
  • Nuclear Proteins / metabolism
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism


  • Cytoskeletal Proteins
  • Membrane Proteins
  • Nuclear Proteins
  • Protein Isoforms
  • TOR1AIP1 protein, human