SCN5A Variant K249M Detail

We estimate the penetrance of LQTS for SCN5A K249M around 24% and the Brugada syndrome penetrance around 9%. SCN5A K249M was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. K249M is not present in gnomAD. K249M has been functionally characterized in 0 papers. This residue is located in a Non_Hotspot region for Brugada syndrome and a Mild_Hotspot region for LQTS. In silico predictions, functional data (if available), and location in structure are equivalent to phenotyping 10 individuals for Brugada syndrome (0 diagnosed with Brugada syndrome) and 5 individuals for LQTS (1 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A K249M around 24% (1/10) and the Brugada syndrome penetrance around 9% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.909 3 29
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: - 0 0 0 0 -
VARIANT FEATURES ALONE: - 15 14 1 0 - -
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.

K249M has 55 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
414 7 M414V,
1643 11 I1643L,
404 15 L404Q, L404V,
1778 14
249 0 K249X,
247 7 V247L,
240 14 V240M,
254 11
418 9 E418K,
250 6
409 12 L409V, L409P,
928 14 L928P,
925 15 I925F,
1641 14
417 13
933 13
246 6
1779 11 T1779M,
412 9 V412D,
924 14 V924I,
245 5 Q245K,
1776 14
244 9
415 7 A415T,
1640 13
256 14
248 6
241 11
419 12 Q419X,
255 13
1772 15 L1772V,
1645 13 T1645M,
239 15 I239V, I239V ,
251 8
410 10 A410V,
1780 14 E1780G,
242 9 A242D,
929 11
416 12 Y416C,
413 10 A413T, A413E,
408 10
253 9
407 11
1783 14
936 15
422 15
1775 11 F1775V, p.F1775LfsX15,
1642 9 G1642E,
252 8
411 6 V411M,
243 11
932 14
257 15
1646 11
1782 13