Simple and rapid characterization of novel large germline deletions in SDHB, SDHC and SDHD-related paraganglioma.

Germline mutations in genes encoding subunits of succinate dehydrogenase (SDH) are associated with hereditary paraganglioma and pheochromocytoma. Although most mutations in SDHB, SDHC and SDHD are intraexonic variants, large germline deletions may represent up to 10% of all variants but are rarely characterized at the DNA sequence level. Additional phenotypic effects resulting from deletions that affect neighbouring genes are also not understood. We performed multiplex ligation-dependent probe amplification, followed by a simple long-range PCR 'chromosome walking' protocol to characterize breakpoints in twenty SDHx-linked paraganglioma-pheochromocytoma patients. Breakpoints were confirmed by conventional PCR and Sanger sequencing. Heterozygous germline deletions of up to 104 kb in size were identified in SDHB, SDHC, SDHD and flanking genes in twenty paraganglioma-pheochromocytoma patients. The exact breakpoint could be determined in sixteen paraganglioma-pheochromocytoma patients of which 15 were novel deletions. In six patients proximal genes were also deleted, including PADI2, MFAP2, ATP13A2 (PARK9), CFAP126, TIMM8B and C11orf57. These genes were either partially or completely deleted, but did not modify the phenotype. This study increases the number of known SDHx deletions by over 50% and demonstrates that a significant proportion of large gene deletions can be resolved at the nucleotide level using a simple and rapid method. This article is protected by copyright. All rights reserved.

Citation

Attje S Hoekstra, Bas van den Ende, Xavier Prado Julià, Lars van Breemen, Kimberly Scheurwater, Carli M Tops, Angelica Malinoc, Peter Devilee, Hartmut Ph Neumann, Jean-Pierre Bayley. Simple and rapid characterization of novel large germline deletions in SDHB, SDHC and SDHD-related paraganglioma. Clinical genetics. 2016 Aug 3

PMID: 27485256

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