The table below lists the 60 rare (MAF<0.0001 in ExAC) protein-altering TNNT2 variants identified in a cohort of 2912 HCM patients. When this rare variant frequency of 0.02060 is compared with a background population rate of 0.00242, there is a statistically significant case excess of 0.01818 (p<0.0001), which suggests that approximately 53 of these variants may be pathogenic.
| No. | Variant (CDS)▼ | Variant (Protein) | Variant Type▼ | Cases (2912)▼ | LMM class | ExAC frequency |
|---|---|---|---|---|---|---|
| 1. | c.487_489delGAG | inframe | 9 | Pathogenic | 0.000000 | |
| 2. | c.860G>A | p.W287X | nonsense | 4 | Pathogenic | 0.000011 |
| 3. | c.281G>A | p.R94H | missense | 4 | Likely Pathogenic | 0.000000 |
| 4. | c.857G>A | p.R286H | missense | 3 | VUS favour pathogenic | 0.000078 |
| 5. | c.275G>A | p.R92Q | missense | 3 | Pathogenic | 0.000000 |
| 6. | c.274C>T | p.R92W | missense | 3 | Pathogenic | 0.000008 |
| 7. | c.252A>T | p.R84S | missense | 2 | VUS | 0.000000 |
| 8. | c.773A>T | p.K258I | missense | 2 | VUS favour pathogenic | 0.000000 |
| 9. | c.536C>T | p.S179F | missense | 2 | Likely Pathogenic | 0.000000 |
| 10. | c.257A>C | p.D86A | missense | 2 | Likely Pathogenic | 0.000008 |
| 11. | c.236T>A | p.I79N | missense | 2 | Pathogenic | 0.000000 |
| 12. | c.856C>T | p.R286C | missense | 2 | VUS favour pathogenic | 0.000011 |
| 13. | c.388C>T | p.R130C | missense | 2 | Likely Pathogenic | 0.000000 |
| 14. | c.251G>C | p.R84T | missense | 2 | VUS favour pathogenic | 0.000000 |
| 15. | c.247G>A | p.E83K | missense | 1 | VUS | 0.000000 |
| 16. | c.833G>C | p.R278P | missense | 1 | VUS favour pathogenic | 0.000000 |
| 17. | c.833G>A | p.R278H | missense | 1 | VUS | 0.000021 |
| 18. | c.281G>T | p.R94L | missense | 1 | Pathogenic | 0.000000 |
| 19. | c.534G>C | p.L178F | missense | 1 | VUS | 0.000000 |
| 20. | c.311C>T | p.A104V | missense | 1 | VUS favour pathogenic | 0.000008 |
| 21. | c.807C>A | p.N269K | missense | 1 | Likely Pathogenic | 0.000000 |
| 22. | c.244G>A | p.G82R | missense | 1 | Likely Pathogenic | 0.000000 |
| 23. | c.249G>C | p.E83D | missense | 1 | VUS | 0.000000 |
| 24. | c.821+1G>T | essential splice site | 1 | Likely Pathogenic | 0.000000 | |
| 25. | c.785A>G | p.N262S | missense | 1 | VUS | 0.000000 |
| 26. | c.330T>G | p.F110L | missense | 1 | Likely Pathogenic | 0.000000 |
| 27. | c.652G>T | p.V218L | missense | 1 | VUS favour benign | 0.000032 |
| 28. | c.421C>T | p.R141W | missense | 1 | Pathogenic | 0.000000 |
| 29. | c.238C>T | p.P80S | missense | 1 | VUS favour pathogenic | 0.000000 |
| 30. | c.283A>G | p.M95V | missense | 1 | VUS | 0.000016 |
| 31. | c.649A>G | p.K217E | missense | 1 | VUS | 0.000000 |
| 32. | c.106G>C | p.A36P | missense | 1 | VUS | 0.000049 |
1. Roddy Walsh, Kate L. Thomson, James S. Ware, Birgit H. Funke, Jessica Woodley, Karen J. McGuire, Francesco Mazzarotto, Edward Blair, Anneke Seller, Jenny C. Taylor, Eric V. Minikel, Exome Aggregation Consortium, Daniel G. MacArthur, Martin Farrall, Stuart A. Cook and Hugh Watkins. Reassessment of Mendelian gene pathogenicity using 7,855 cardiomyopathy cases and 60,706 reference samples. Genet Med. 2016 doi:10.1038/gim.2016.90.
2. Alfares AA, Kelly MA, McDermott G, Funke BH, Lebo MS, Baxter SB, Shen J, McLaughlin HM, Clark EH, Babb LJ, Cox SW, DePalma SR, Ho CY, Seidman JG, Seidman CE, Rehm HL. Results of clinical genetic testing of 2,912 probands with hypertrophic cardiomyopathy: expanded panels offer limited additional sensitivity. Genet Med. 2015 Nov;17(11):880-8.