Recently, autosomal dominant genetic mutations of the subunits of succinyl dehydrogenase (SDHx), a protein within the mitochondrial electron transport chain, have been associated with hereditary paraganglioma syndromes
(PGL1 through PGL4).
Hoffmann et al., "Impact of screening kindreds for SDHD p.Cys11X as a common mutation associated with paraganglioma syndrome type 1," The Journal of Clinical Endocrinology and Metabolism, vol.
Cecchini et al., "The endemic paraganglioma syndrome type 1: Origin, spread, and clinical expression," The Journal of Clinical Endocrinology and Metabolism, vol.
The discovery of the succinate dehydrogenase genes associated with the development of familial paraganglioma syndromes, in particular the SDHB gene, frequently associated with malignant tumors, brought new insights into the management and prognosis of paragangliomas.
Bilateral pheochromocytoma in childhood can occur as part of familial tumor syndromes such as MEN 2A/2B, neurofibromatosis Type 1, familial paraganglioma syndromes
, and VHL syndrome (2,6,8).
MEN 2, neurofibromatosis type 1 (NF1), von Hippel-Lindau (VHL) syndrome, and familial paraganglioma syndromes
due mutations of succinate dehydrogenase subunits B and D (SDHB and SDHD) represent the 5 main hereditary syndromes causing PPGLs among a diverse variety of other neoplasms.
The hereditary cases tend to run in families as a component of disease syndromes of the genetic origin, such as von Hippel Lindau disease, Multiple Endocrine Neoplasia type II, Neurofibromatosis type I (NF1), familial carotid body tumours and paraganglioma syndromes
Pacak, "Genetics of pheochromocytoma and paraganglioma syndromes
: new advances and future treatment options," Current Opinion in Endocrinology, Diabetes and Obesity, vol.
(3) Familial paraganglioma syndromes
are caused by germline mutations in the genes that encode for the mitochondrial enzyme succinyl dehydrogenase, and they often occur as multiple paragangliomas.
(8) Major hereditary disorders associated with paraganglioma or pheochromocytoma are multiple endocrine neoplasia, von Hippel-Lindau disease, neurofibromatosis, and familial paraganglioma syndromes 1 to 4.
Paragangliomas and paraganglioma syndromes. CMS Curr Top Otorhinolaryngol Head Neck Surg.
Loss of SDHB expression is regarded as a surrogate marker for some of the familial paraganglioma syndromes
caused by SDHx mutations (36); therefore, immunohistochemical testing for SDHB has become a part of the routine assessment of these lesions in many centers.