Introduction: Great progress has been achieved in the fields, especially genetics in pheochromocytomas/ paragangliomas . However, these findings were obtained mainly from Europe and USA. Therefore, it remains obscure whether genetic mutation plays indeed pathological role in populations outside these geographic locations. Major aim of this lecture is to overview the recent progress of genetic testing in Japan.
Results: 1) Since 2007, we have carried out genetic testing in 277cases in Japan. In 227 index cases, we found 81cases whose genetic mutations were
positive and summarized herein : SDHB 39 cases, SDHD 11 cases, SDHA 1 case,VHL 16 cases, RET 4 cases, TMEM 127 5 cases, MAX 5 cases. Consequently, notably high degree (81/227=35.7%) of patients carry genetic mutation, similar to those of previous reports from USA and Europe.
2) Growing evidence suggest that mutation of SDHB is highly associated with abdominal paraganglioma and the following distant metastasis.
In the present study, in 39 patients whose SDHB mutations were positive,
14 patients (14/39=35.9%) were developed to malignant status. Also, they mainly suffered from paraganglioma (34/39=87.2). On the contrary, analysis of blood taken from 46 cases of malignant pheochromocytomas subjects led to the identification of 14 SDHB mutations(14/46=30.4%). These findings regarding SDHB mutations are, in agreement with previous reports.
Conclusion and perspective: Also in Japan, 1) remarkable high degree of patients (around 40%) carry genetic mutation and 2)SDHB is highly involved in pathogenesis of malignant pheochromocytomas. Thus, genetic testing is prerequisite for diagnosis and treatment of pheochromocytomas/ paragangliomas in our country.