Somatic mosaicism of PCDH19 mutation in a family with low-penetrance EFMR

A. Terracciano, N. Specchio, F. Darra, A. Sferra, B. Dalla Bernardina, F. Vigevano, E. Bertini

Research output: Contribution to journalArticle


The occurrence of epilepsy with mental retardation limited to females (EFMR; MIM 300088) has been recently associated to mutations in the PCDH19 gene, located on chromosome X and encoding for protocadherin 19. EFMR shows a rare X-linked inheritance wherein affected females may be segregating a mutation through unaffected transmitting males (Fabisiak and Erickson Clin Genet 38 (5):353-358, 1990; Juberg and Hellman J Pediatr 79:726-732, 1971; Ryan et al. Nat Genet 17(1):92-95, 1997). The description of a pedigree segregating PCDH19 mutations from unaffected mothers to patients (Depienne et al. Hum Mutat 32:E1959-1975, 2011; Dibbens et al. Neurology 76:1514-1519, 2011) complicates disease inheritance and genetic counseling. In the present study, we describe a PCDH19 mutation segregating from an asymptomatic mother to an EFMR patient. In order to correlate the healthy phenotype with the genotype of the transmitting mother, we quantified in a few tissues the level of the mutant allele by real-time PCR, disclosing a somatic mosaicism. This finding has a great impact on genetic counseling.

Original languageEnglish
Pages (from-to)341-345
Number of pages5
Issue number4
Publication statusPublished - Nov 2012



  • Epilepsy
  • Mosaicism
  • PCDH19

ASJC Scopus subject areas

  • Genetics(clinical)
  • Cellular and Molecular Neuroscience
  • Genetics

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