A recent study that analysed the age distribution in patients with renal cell carcinoma (RCC) in the SEER-17 database concluded that early age of onset might be a sign of hereditary RCC. Among patients with RCC, 5–8% of cases are hereditary. Moreover, there is evidence to suggest that nearly 60% of patients with RCC have an hereditary predisposition. However, there are no guidelines for patient selection for RCC mutation testing. The age of onset for both hereditary RCC and RCC syndromes is much younger than that observed in the general population—46 years and 64 years, respectively. Generally, family history, bilateral or multifocal tumours, associated clinical manifestation of RCC and specific tumour histologies are important signs in the selection of patients for mutation analysis. This study concluded that early age of onset of kidney cancer should be regarded as a major indicator of a hereditary RCC and, when encountered by clinicians, should trigger referral to a geneticist for counselling and mutation screening.