SCN5A Variant R1321K Detail

We estimate the penetrance of LQTS for SCN5A R1321K around 9% and the Brugada syndrome penetrance around 17%. SCN5A R1321K was found in a total of 1 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. R1321K is present in 1 alleles in gnomAD. R1321K has been functionally characterized in 0 papers. This residue is located in a Mild_Hotspot region for Brugada syndrome and a Non_Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (1 diagnosed with Brugada syndrome) and 5 individuals for LQTS (0 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A R1321K around 9% (0/11) and the Brugada syndrome penetrance around 17% (1/11).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-2.44 0.925 6.72 0.839 28 5
PROVEAN scores less than -2 are considered deleterious. REVEL scores higher than 0.5 or 0.75 are considered likely pathogenic (higher sensitivity with the former cutoff, higher specificity with the latter cutoff). A PolyPhen-2 score of 0.85 or greater is considered likely pathogenic. BLAST-PSSM reflects the evolutionary conservation of residue substitutions, more negative numbers indicate fewer observations of the specific substitution than is expected. Penetrance Density is our previously published method to calculate the average BrS/LQTS probability density in a shell of residues surrounding a residue of interest (Kroncke et al. 2019).

Reported Carrier Data

PubMed ID Year Carriers Unaffected LQT3 BrS1 Other Other Disease
LITERATURE, COHORT, AND GNOMAD: - 1 1 0 0 -
VARIANT FEATURES ALONE: - 15 14 0 1 - -
Summary totals might not agree with the literature table because of duplicate patients, which were excluded from the total counts. We do not distinguish here between multiple missense codons. Missense variants are combined across degenerate codon substitutions since codon-level data were not consistently available for curation.

R1321K has 35 previously observed neighbors within 15 angstroms

A residue within a folded protein on average has nearest neighbors that fall roughly into two shells: a "nearest" neighbor around 5-6 angstroms and a second shell around 11 angstroms. All variants shown in the rightmost column have been observed in at least one individual in the literature or gnomAD.

Neighbor Distance (Angstroms) Variants Observed in Individuals
1328 12 V1328M,
1659 10
1271 12 W1271C,
1480 9 c.4438-1C>T, c.4437+5G>A,
1315 6
1314 9 c.3940_3941delCT,
1320 7 M1320I,
1656 12
1477 13 K1477N,
1313 10
1660 13 I1660V, I1660S,
1329 15 G1329S,
1310 15
1316 7 R1316L, R1316Q,
1319 6 G1319V,
1479 12
1473 14 F1473C, F1473S,
1663 14
1662 13
1324 8
1481 13 G1481V, G1481R, G1481E,
1317 7 F1317C,
1327 13
1318 6
1321 0 R1321K,
1323 9 V1323G,
1212 15 p.I1212del,
1322 7 c.3963+2T>C, c.3963+4A>G,
1312 9
1326 11 A1326S,
1311 13 L1311P,
1476 10 Q1476R, Q1476X,
1655 13
1325 8 N1325S,
1208 15 E1208K, E1208X,