Mutational analysis of TSC1 and TSC2 genes in Japanese patients with tuberous sclerosis complex

Abstract

We have surveyed the mutations of TSC1 and TSC2 from 38 (25 sporadic, 11 familial, and 2 unknown) Japanese patients with tuberous sclerosis complex. In 23 of 38 subjects, we detected 18 new mutations in addition to 4 mutations that had been previously reported. We also found 3 new polymorphisms. The mutations were not clustered on a particular exon in either of the genes. Seven TSC1 mutations found in 3 familial and 4 sporadic cases were on the exons (3 missense, 2 nonsense point mutations, a 1-base insertion, and a 2-bp deletion). Fifteen TSC2 mutations were found in 5 familial cases, 10 sporadic cases, and 1 unknown case. The 12 mutations were on the exons (8 missense, 1 nonsense point mutations, a 1-bp insertion, a 5-bp deletion, and a 4-bp replacement) and 3 point mutations were on the exon–intron junctions. Although the patients with TSC2 mutations tend to exhibit relatively severe mental retardation in comparison to those with TSC1 mutations, a genotype–phenotype correlation could not yet be established. The widespread distribution of TSC1/TSC2 mutations hinders the development of a simple diagnostic test, and the identification of individual mutations does not provide the prediction of prognosis.

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Received: April 5, 1999 / Accepted: June 12, 1999

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Zhang, H., Nanba, E., Yamamoto, T. et al. Mutational analysis of TSC1 and TSC2 genes in Japanese patients with tuberous sclerosis complex. J Hum Genet 44, 391–396 (1999). https://doi.org/10.1007/s100380050185

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  • Key words Tuberous sclerosis complex
  • TSC1 gene
  • TSC2 gene
  • Hamartin
  • Tuberin
  • Mutation

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