Hereditary pheochromocytoma\/paraganglioma (HPP) syndromes are genetic diseases based on heterozygous pathogenic variants in an SDH<\/em> gene, the MAX<\/em> gene, or the TMEM127<\/em> gene. They are characterized by typically benign tumors originating in the neural crest. Extra-adrenal parasympathetic paragangliomas are frequently located in the area of the brain base, neck, and upper mediastinum and are generally not secretory. In contrast, sympathetic paragangliomas are usually located in the area of the lower mediastinum, abdomen, and pelvis and are hormone-producing. In addition, there is an association with gastrointestinal stromal tumors, renal cell tumors, and papillary thyroid adenomas.<\/p>\n<\/div> Synonyms:<\/p>\n<\/div><\/div><\/div> Familiar glomus tumors, familiar non-chromaffinic paragangliomas<\/p>\n<\/div><\/div><\/div><\/div> Genes:<\/p>\n<\/div><\/div><\/div> SDHx (SDHA, SDHB, SDHC, SDHD, SDHAF2)<\/i><\/p>\n MAX<\/i><\/p>\n TMEM127<\/i><\/p>\n<\/div><\/div><\/div><\/div> Gen\u00ade products:<\/p>\n<\/div><\/div><\/div> SDH (succinate dehydrogenase) with subunits A-D, SDHAF2 Function:<\/p>\n<\/div><\/div><\/div> Tumorsuppressoren<\/p>\n<\/div><\/div><\/div><\/div> Erb\u00adgang:<\/p>\n<\/div><\/div><\/div> Autosomal dominant: SDHA, SDHB, SDHC, TMEM127<\/em> Prevalence:<\/p>\n<\/div><\/div><\/div> The incidence is around 1:300.000 per year.<\/p>\n<\/div><\/div><\/div><\/div> Genotype-phenotype correlation:<\/p>\n<\/div><\/div><\/div> SDHB<\/em>:<\/p>\n SDHD, SDHC, SDHAF2:<\/em><\/p>\n Penetrance:<\/p>\n<\/div><\/div><\/div> Pathogenic SDHD<\/em> variants: 90%
\nMAX (MYC-associated factor X)
\nTMEM127 (transmembrane protein)<\/p>\n<\/div><\/div><\/div><\/div>
\nPaternal transmission: SDHD, SDHAF2, MAX<\/em><\/p>\n<\/div><\/div><\/div><\/div>\n
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\nPathogenic SDHB<\/em> variants: 30%-50%
\nPathogenic SDHA<\/em>, SDHC<\/em>, SDHAF2<\/em>, and TMEM127<\/em> variants: unclear to date<\/p>\n<\/div><\/div><\/div><\/div><\/div><\/div>