mTOR mutations in Smith-Kingsmore syndrome: Four additional patients and a review

Clin Genet. 2018 Apr;93(4):762-775. doi: 10.1111/cge.13135. Epub 2018 Feb 13.

Abstract

Smith-Kingsmore syndrome (SKS) OMIM #616638, also known as MINDS syndrome (ORPHA 457485), is a rare autosomal dominant disorder reported so far in 23 patients. SKS is characterized by intellectual disability, macrocephaly/hemi/megalencephaly, and seizures. It is also associated with a pattern of facial dysmorphology and other non-neurological features. Germline or mosaic mutations of the mTOR gene have been detected in all patients. The mTOR gene is a key regulator of cell growth, cell proliferation, protein synthesis and synaptic plasticity, and the mTOR pathway (PI3K-AKT-mTOR) is highly regulated and critical for cell survival and apoptosis. Mutations in different genes in this pathway result in known rare diseases implicated in hemi/megalencephaly with epilepsy, as the tuberous sclerosis complex caused by mutations in TSC1 and TSC2, or the PIK3CA-related overgrowth spectrum (PROS). We here present 4 new cases of SKS, review all clinical and molecular aspects of this disorder, as well as some characteristics of the patients with only brain mTOR somatic mutations.

Keywords: MINDS syndrome; Smith-Kingsmore syndrome; constitutive mosaicism; germline mosaicism; gonadal mosaicism; mTOR; macrocephaly; megalencephaly; somatic mosaicism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Brain / metabolism*
  • Brain / physiopathology
  • Cell Proliferation / genetics
  • Child
  • Class I Phosphatidylinositol 3-Kinases / genetics
  • Developmental Disabilities / genetics
  • Developmental Disabilities / physiopathology
  • Female
  • Humans
  • Intellectual Disability / genetics
  • Intellectual Disability / physiopathology
  • Male
  • Megalencephaly / diagnostic imaging
  • Megalencephaly / genetics*
  • Megalencephaly / physiopathology
  • Mutation
  • Neuronal Plasticity / genetics
  • Proto-Oncogene Proteins c-akt / genetics
  • Smith-Lemli-Opitz Syndrome / diagnostic imaging
  • Smith-Lemli-Opitz Syndrome / genetics*
  • Smith-Lemli-Opitz Syndrome / physiopathology
  • TOR Serine-Threonine Kinases / genetics*
  • Tuberous Sclerosis Complex 1 Protein / genetics
  • Tuberous Sclerosis Complex 2 Protein / genetics

Substances

  • TSC1 protein, human
  • TSC2 protein, human
  • Tuberous Sclerosis Complex 1 Protein
  • Tuberous Sclerosis Complex 2 Protein
  • MTOR protein, human
  • Class I Phosphatidylinositol 3-Kinases
  • PIK3CA protein, human
  • Proto-Oncogene Proteins c-akt
  • TOR Serine-Threonine Kinases