High prevalence of SDHB mutations in head and neck paraganglioma in Belgium.
BACKGROUND
Recent reports have found genetic mutations in up to one quarter of patients harbouring pheochromocytoma and/or paraganglioma. This high prevalence was mainly due to the discovery of the role of SDH genes. While SDHD has been more frequently associated with the pathogenesis of head and neck paragangliomas, SDHB mutations were mainly associated with malignant and/or extra-adrenal pheochromocytoma/paraganglioma.


OBJECTIVE
To look for mutations in susceptibility genes and genotype-phenotype correlations in patients with pheochromocytoma and/or paraganglioma from Belgium.


METHODS
Screening of the coding parts of SDH, VHL and RET genes was performed by SSCP in patients with pheochromocytoma and/or paraganglioma diagnosed at or referred to the Cliniques Universitaires Saint Luc from May 2003 to May 2006.


RESULTS
Fifty-six unrelated patients were included (36 head and neck paragangliomas, including six familial cases and 30 sporadic cases; 18 abdominal pheochromocytoma/paraganglioma and two paraganglioma of the cauda equina). The overall prevalence of mutations was 41% (n = 23 including 19 head and neck paragangliomas and four abdominal pheochromocytoma/paraganglioma), mainly due to SDH mutations. While SDHD mutations were found in all patients with familial head and neck paragangliomas, in sporadic cases, the prevalence of SDHB mutations (n = 8, 27%) was twice that of SDHD mutations (n = 4, 13%). Patients harbouring SDHB mutations had unilateral late-onset head and neck tumours without evidence of recurrence or malignancy.


CONCLUSIONS
This Belgian series confirms the elevated prevalence of predisposing mutations in patients with head and neck and extra-adrenal paragangliomas, but differs from previous reports by the high frequency of SDHB mutations associated with head and neck paragangliomas without evidence of recurrence or malignancy.
Persu
Alexandre
A
Department of Cardiology, Cliniques Universitaires Saint Luc, Université Catholique de Louvain, Brussels, Belgium. alexandre.persu@card.ucl.ac.be
Hamoir
Marc
M
Grégoire
Vincent
V
Garin
Pierre
P
Duvivier
Etienne
E
Reychler
Hervé
H
Chantrain
Gilbert
G
Mortier
Geert
G
Mourad
Michel
M
Maiter
Dominique
D
Vikkula
Miikka
M
D000328:Adult; D000368:Aged; D001530:Belgium; D005260:Female; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing; D005838:Genotype; D006258:Head and Neck Neoplasms / Q000235:genetics*; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D008875:Middle Aged; D009154:Mutation; D010235:Paraganglioma / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D015995:Prevalence; D013385:Succinate Dehydrogenase / Q000235:genetics*
D008565:Membrane Proteins; C108096:SDHC protein, human; C491545:SDHD protein, human; C108095:SDHB protein, human; D013385:Succinate Dehydrogenase