Table 1.

Risk stratification in MEN 2.

Risk group	Risk type	RET codon	Youngest patient	Age for prophylactic surgery1)
3	Highest	922, 918, 883	9 months	<2 years
2a	Very high	634, 630	12 months	<2 years
2b	High	620, 618, 611, 609	5 years	<5 years
1	Low	891, 804, 791, 790, 768	6 to 22 years	<10 years

¹Based on the youngest observed patient.