| GENE | LOCUS or SYNDROME | AMINO ACID CHANGE | NUCLEOTIDE CHANGE | EXON | ETHNICITY (Number of families) | REFERENCES |
| KCNQ1 (KvLQT1) | Jervell and Lange-Nielson Syndrome | FS150 | 451delCT | exon 2 (S2) | Amish (1) | Chen 1999 |
| IVS2+1G>A* | S2 | N/A (1) | Splawski 2000 | |||
| *Found in Long QT by Splawski 2000 | ||||||
| Y171X | 513C>G | exon 3 (S2-S3) | N/A (1) | Wang 2002 | ||
| FS189 | 567insG | exon 3 (S2-S3) | Scottish (1) | Splawski 1997 | ||
| FS191 | 572delTGCGC* | exon 3 (S2-S3) | Norwegian (1); Norwegian (7); Norwegian (2) | Tyson 1997; Tranebjaerg 1999; Tyson 2000 | ||
| *Found in Long QT by Ackerman 1999 | ||||||
| 585del1 | exon 3 (S2-S3) | N/A (1) | Wang 2002 | |||
| D202N | 604G>A | exon 3 (S2-S3) | N/A (1) | Wang 2002 | ||
| R243H | 728G>A | exon 5 (S4) | French (1); British (1) | Mohammed-Panah 1999; Tyson 2000 | ||
| E261D | 783G>A | exon 6 (S4-S5) | Norwegian (1), Norwegian (1) | Tranebjaerg 1999, Tyson 2000 | ||
| G269D | 806G>A* | exon 6 (S5) | N/A (1) | Wang 2002 | ||
| *Found in Long QT by Donger 1997, Splawski 2000 | ||||||
| G272D | 815G>A | exon 6 (S5) | British (1) | Tyson 2000 | ||
| W305S | 914G>C | exon 6 (Pore) | N/A (1); Moroccan (2) | Chouabe 1997; Neyroud 1998* | ||
| *Heterozygotes were asymptomatic | ||||||
| FS337 | 1008delC | exon 7 (S6) | British (1) | Tyson 2000 | ||
| 395 | 1188delC | exon 9 (C-term) | Haitian (1) | Wei 2000 | ||
| R518X | 1552C>T* | exon 12 (C-term) | Norwegian (4); N/A (1); Norwegian (3), British (1); Caucasian (1) | Tranebjaerg 1999; Splawski 2000; Tyson 2000; Wei 2000 | ||
| *Found in Long QT by Larsen 1999b, Splawski 2000 | ||||||
| Q530X | 1588C>T | exon 12 (C-term) | Norwegian (3); Norwegian (3); N/A (1) | Tranebjaerg 1999; Tyson 2000; Splawski 2000 | ||
| IVS13-1G>A | British (1) | Tyson 2000 | ||||
| 1244del7ins8 | exon 13 (C-term) | Kabylia (2) | Neyroud 1997 | |||
| T587M | 1760C>T* | exon 14 (C-term) | N/A (1) | Neyroud 1999 | ||
| *Found in Long QT by Itoh 1998 | ||||||
| R594Q | 1781G>A* | exon 15 (C-term) | British (1) | Tyson 2000 | ||
| *Found in Long QT by Splawski 2000 | ||||||
| 1892del 20 | exon 15 (C-term) | N/A (1) | Neyroud 1999 | |||
| Long QT Syndrome | 71del3 | 211del9 | exon 1 (N-term) | N/A (1) | Ackerman 1999a, b | |
| Y111C | 332A>G | exon 1 (N-term) | N/A (1) | Splawski 2000 | ||
| F157C | 470T>G | exon 1 (S2) | Danish (1) | Larsen 1999a | ||
| IVS2+1G>A* | S2 | N/A (1) | Splawski 2000 | |||
| *Found in JLNS by Tyson 2000 | ||||||
| IVS2+5G>A | S2 | N/A (1) | Ackerman 1999 | |||
| E160K | 478G>A | exon 3 (S2) | N/A (1) | Splawski 2000 | ||
| F167W168delG | 500delTCG | exon 3 (S2) | N/A (1) | Wang 1996 | ||
| G168R | 502G>A | exon 3 (S2) | N/A (3); N/A (3) | Splawski 1998, Splawski 2000 | ||
| G168R | 502G>C | exon 3 (S2) | French (1) | Donger 1997 | ||
| 504delG | exon 3 (S2) | Caucasian (1) | Wei 2000 | |||
| R174C | 520C>T | exon 3 (S2-S3) | French (1) | Donger 1997 | ||
| R174H | 521G>A | exon 3 (S2-S3) | N/A (1) | Splawski 2000 | ||
| A178P | 532G>C | exon 3 (S2-S3) | N/A (1) | Wang 1996 | ||
| A178T | 532G>A | exon 3 (S2-S3) | Japanese (1) | Tanaka 1997 | ||
| G179S | 535G>A | exon 3 (S2-S3) | N/A (1) | Splawski 2000 | ||
| Y184S | 551A>C | exon 3 (S2-S3) | Dutch (1); N/A (1) | Jongbloed 1999; Splawski 2000 | ||
| G189R | 565G>A | exon 3 (S2-S3) | N/A (1); Dutch (2) | Wang 1996; Jongbloed 1999 | ||
| R190Q | 569G>A | exon 3 (S2-S3) | N/A (1), French (1) | Wang 1996; Donger 1997 | ||
| FS191 | 572delTGCGC* | exon 3 (S2-S3) | N/A (1) | Ackerman 1999 | ||
| *Found in JLNS by Tyson 1997, Tranebjaerg 1999, Tyson 2000 | ||||||
| A194P | 580G>C | exon 3 (S2-S3) | N/A (1) | Splawski 2000 | ||
| S225L | 674C>T | exon 4 (S4) | Italian (1); N/A (1) | Priori 1999; Splawski 2000 | ||
| D202N | N/A (1) | Wang 2002 | ||||
| D242N | 724G>A | exon 5 (S4-S5) | Japanese (1) | Itoh 1998 | ||
| R243C | 727C>T | exon 5 (S4-S5) | N/A (1) | Splawski 2000 | ||
| W248R | 742T>C | exon 5 (S4-S5) | N/A (1) | Splawski 2000 | ||
| L250H | 749T>A | exon 5 (S4-S5) | Japanese (1) | Itoh 1998 | ||
| V254M | 760G>A | exon 5 (S4-S5) | N/A (1); French (1); N/A (2) | Wang 1996; Donger 1997; Splawski 2000 | ||
| E261K | 781G>A | exon 6 (S4-S5) | French (1) | Donger 1997 | ||
| L266P | 797T>C | exon 6 (S5) | N/A (1) | Splawski 2000 | ||
| G269S | 805G>A | exon 6 (S5) | N/A (1) | Ackerman 1999 | ||
| G269D | 806G>A* | exon 6 (S5) | French (1); N/A (2) | Donger 1997; Splawski 2000 | ||
| *Found in JLNS by Wang 2002 | ||||||
| L273F | 817C>T | exon 6 (S5) | N/A (1); N/A (1) | Wang 1996; Splawski 2000 | ||
| Y281C | 842T>G | exon 6 (S5) | Italian (1) | Priori 1999 | ||
| A300T | 898G>A | exon 6 (S5/Pore) | N/A (1); Italian (1) | Priori 1998*; Priori 1999 | ||
| *Mutation was recessive | ||||||
| G306R | 916G>A | exon 6 (Pore) | N/A (1) | Wang 1996 | ||
| 306 | 921delGGT | exon 6 (Pore) | N/A (1) | Li 1998 | ||
| IVS6+1G>T | Pore | N/A (1) | Splawski 2000 | |||
| IVS6-2A>C | Pore | N/A (1) | Splawski 2000 | |||
| IVS6-1G>T | S6 | N/A (1) | Murray 1999 | |||
| T309I | exon 7 (Pore) | Taiwanese (1) | Ko 2001 | |||
| T309R | 926C>G | exon 7 (Pore) | French (1) | Donger 1997 | ||
| V310I | 928G>A | exon 7 (Pore) | N/A (1) | Splawski 2000 | ||
| T311I | 932C>T | exon 7 (Pore) | Finnish (1) | Saarinen 1998 | ||
| T312I | 935C>T | exon 7 (Pore) | N/A (1); N/A (1) | Wang 1996; Splawski 2000 | ||
| I313M | 939C>G | exon 7 (Pore) | Japanese (1) | Tanaka 1997 | ||
| G314S | 940G>A | exon 7 (Pore) | N/A (1); French (2); Japanese (2); N/A (1); Dutch (1) | Russell 1996; Donger 1997; Itoh 1998; Splawski 1998; Jongbloed 1999 | ||
| Y315C | 944A>G | exon 7 (Pore) | N/A (1); Italian (1) | Splawski 1998; Priori 1999 | ||
| Y315S | 944A>C | exon 7 (Pore) | French (2); Jongbloed (1) | Donger 1997 | ||
| D317N | 949G>A | exon 7 (Pore) | German (1); Finnish (1) | Wollnik 1997; Saarinen 1998 | ||
| K318N | 954G>C | exon 7 (Pore) | N/A (1) | Splawski 1998 | ||
| P320A | 958C>G | exon 7 (Pore) | French (1) | Donger 1997 | ||
| G325R | 973G>A | exon 7 (S6) | Japanese (1); French (1); N/A (2) | Tanaka 1997; Donger 1997; Splawski 2000 | ||
| 340delF | 1017delCTT | exon 7 (S6) | N/A (1); N/A (1) | Ackerman 1998a; Splawski 2000 | ||
| A341E | 1022C>A | exon 7 (S6) | N/A (2); N/A (1); N/A (2) | Wang 1996; Berthet 1999*; Splawski 2000 | ||
| *Patients also had mutations in HERG | ||||||
| A341V | 1022C>T | exon 7 (S6) | N/A (5); N/A (2); French (1); Japanese (1), White (1); N/A (?) | Wang 1996; Russell 1996; Donger 1997; Li 1998; Splawski 2000 | ||
| L342F | 1024C>T | exon 7 (S6) | French (1) | Donger 1997 | ||
| A344V | 1031C>T | exon 7 (S6) | French (1) | Donger 1997 | ||
| G345R | 1033G>C | exon 7 (S6) | Dutch (1) | van den Berg 1997 | ||
| G345E | 1034G>A | exon 7 (S6) | N/A (1) | Wang 1996 | ||
| S349W | 1046C>G | exon 7 (S6) | N/A (1) | Splawski 2000 | ||
| L353P | 1058T>C | exon 7 (S6) | N/A (1) | Splawski 1998 | ||
| IVS7-1G>A | S6 | Italian (1), Irish (1), American (2); N/A (1); French (2); N/A (1); N/A (1) | Li 1998; Kanters 1998; Murray 1999; Ackerman 1999; Splawski 2000 | |||
| IVS7-1G>C | S6 | N/A (1) | Murray 1999 | |||
| Q356X | 1066C>T | exon 8 (C-term) | N/A (1) | Splawski 2000 | ||
| R366W | 1096C>T | exon 8 (C-term) | N/A (1); Danish (1) | Splawski 1998; Larsen 1997a | ||
| R366Q | 1097G>A | exon 8 (C-term) | N/A (1) | Splawski 2000 | ||
| R366P | 1097G>C | exon 8 (C-term) | Japanese (1) | Tanaka 1997 | ||
| A371T | 1111G>A | exon 8 (C-term) | French (1) | Donger 1997 | ||
| S373P | 1117T>C | exon 8 (C-term) | Dutch (1) | Jongbloed 1999 | ||
| T391I | 1172C>T | exon 9 (C-term) | N/A (1) | Splawski 2000 | ||
| W392R | 1174T>C | exon 9 (C-term) | Dutch (1) | Jongbloed 1999 | ||
| 1343delC | exon 10 (C-term) | N/A (1) | Neyroud 1999 | |||
| P448R | 1343C>G | exon 10 (C-term) | N/A (2); American (1) | Splawski 2000; Yang 2002* | ||
| *Identified as a polymorphism | ||||||
| ~Variant has been found in 22%-28% of asymptomatic Japanese subjects - M. Horie, W. Shimizu | ||||||
| R518X | 1552C>T* | exon 12 (C-term) | Swedish (1), N/A (2) | Larsen 1999b, Splawski 2000 | ||
| *Found in JLNS byTranebjaerg 1999, Splawski 2000, Tyson 2000, Wei 2000 | ||||||
| A525T | 1573G>A | exon 12 (C-term) | Swedish (1) | Larsen 1999b | ||
| Q530X | 1558C>T | exon 12 (C-term) | N/A (1) | Splawski 2000 | ||
| R539W | 1615C>T | exon 13 (C-term) | N/A | ?? | ||
| R555C | 1663C>T | exon 13 (C-term) | French (1) | Donger 1997 | ||
| S566F | 1697C>T | exon 14 (C-term) | N/A (3) | Splawski 2000 | ||
| R583C | 1747C>T | exon 15 (C-term) | N/A (1), American (1) | Splawski 2000, Yang 2002 | ||
| T587M | 1760C>T* | exon 15 (C-term) | Japanese (1) | Itoh 1998 | ||
| *Found in JLNS by Neyroud 1999 | ||||||
| R591H | 1772G>A | exon 15 (C-term) | N/A (1) | Neyroud 1999 | ||
| R594Q | 1781G>A* | exon 15 (C-term) | N/A (1) | Splawski 2000 | ||
| *Found in JLNS by Tyson 2000 | ||||||
| FS631 | 1893insC | exon 16 (C-term) | N/A (1) | Neyroud 1999 | ||