TABLE 2.
Germline SDHx Mutations and Their Clinical Associations
| SDHA | SDHB | SDHC | SDHD | SDHAF2 | |
|---|---|---|---|---|---|
| Presentation Type | PGL-5 | PGL-4 | PGL-3 | PGL-1 | PGL-2 |
| Chromosome Location | 5p15 | 1p35-36.1 | 1q21 | 11q23 | 11q11.3 |
| Inheritance Pattern | Autosomal dominant | Autosomal dominant | Autosomal dominant | Autosomal dominant, maternal imprinting | Autosomal dominant, maternal imprinting |
| Catecholamine Secreting | Yes | Frequent | Occasionally | Occasionally | Unknown |
| Malignant/Metastatic | Yes | Frequent | Unknown | Occasionally | Unknown |
| Head and Neck PGLs | Yes | Yes | Frequent | Frequent | Frequent |
| PCC (Any Abdominal) | Frequent | Frequent | Occasionally | Occasionally | Unknown |
| Associated with GIST | Frequent | Yes | Yes | Yes | Unknown |
| Associated with Thyroid Cancer | Unknown | Yes | Unknown | Yes | Unknown |
| Associated with Renal Tumors (RCC and Oncocytoma) | Unknown | Yes | Yes | Unknown | Unknown |
| Associated with NBL | Unknown | Yes | Unknown | Unknown | Unknown |
Abbreviations: PGL, paraganglioma: PCC, pheochromocytoma: GIST, gastrointestinal stromal tumor; RCC, renal cell carcinoma; NBL, neuroblastoma.