RET Mutation RET exon Families (n); GC (n) RET Mutation RET exon Families (n); GC (n) G321R Exon 5 1; 4 K666N Exon 11 1; 1 T338I Exon 5 1;2 K666M Exon 11 1; 8 A510V Exon 8 1;1 S686N Exon 11 1; 2 E511K Exon 8 1;1 M700L Exon 11 1; 1 C531R Exon 8 1;1 R770Q Exon 13 1; 3 G550E Exon 9 1;1 N777S Exon 13 1; 4 R600Q Exon 10 1; 6 V778I Exon 13 2; 6 K603Q Exon 10 1; 3 Q781R Exon 13 1; 1 Y606C Exon 10 1;1 E805K Exon 14 1; 1 E616Q Exon 10 1;1 E818K Exon 14 1; 1 F619F Exon 10 1;1 S819I Exon 14 1; 1 C620L Exon 10 1;1 R833C Exon 14 1; 1 E623K Exon 10 1;1 P841L Exon 14 1; 1 C630G Exon 11 1;1 P841P Exon 14 1; 1 C630S Exon 11 1; 4 E843D Exon 14 1; 1 D631V Exon 11 2; 6 R844Q Exon 14 1; 1 D631E Exon 11 1; 1 R844L Exon 14 1; 5 D631D Exon 11 1; 3 A845A Exon 14 1; 1 E632K Exon 11 2; 2 M848T Exon 14 1; 1 R635G Exon 11 2; 2 L881V Exon 15 1; 6 T636P Exon 11 1; 3 R886W Exon 15 1; 2 A640G Exon 11 1; 1 S904C Exon 15 1; 3 V648I Exon 11 2; 5 S904F Exon 15 1; 2 S649L Exon 11 8; 15 R912Q Exon 16 1; 10 H665Q Exon 11 1; 4 M918V Exon 16 1; 2

Table 1: Germline RET point mutations of unknown significance; data derived from “ARUP, MEN 2 RET database, PUBMED and The Human Gene Mutation Database.