SCN5A Variant L250M Detail

We estimate the penetrance of LQTS for SCN5A L250M around 27% and the Brugada syndrome penetrance around 10%. SCN5A L250M was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L250M is not present in gnomAD. L250M 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 L250M around 27% (1/10) and the Brugada syndrome penetrance around 10% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.9 3 33
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.

L250M has 60 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 10 M414V,
1643 10 I1643L,
404 10 L404V, L404Q,
249 6 K249X,
247 5 V247L,
254 5
1771 15 I1771T,
418 14 E418K,
926 13
250 0
409 10 L409P, L409V,
928 9 L928P,
925 11 I925F,
1650 15 L1650F,
260 14
366 15
933 13
258 12 V258A,
246 6
1779 14 T1779M,
412 8 V412D,
924 9 V924I,
927 13 N927S, N927K,
245 9 Q245K,
369 14 M369K,
244 11
415 11 A415T,
1640 14
256 10
921 13
405 11
248 8
261 15
241 13
920 14
930 13 c.2787+17_2787+18insACACACACACACACACACACACA, c.2788-6C>T,
255 9
1772 14 L1772V,
1645 14 T1645M,
251 5
410 9 A410V,
242 12 A242D,
929 9
416 15 Y416C,
413 12 A413E, A413T,
408 6
253 5
407 8
1775 12 p.F1775LfsX15, F1775V,
1642 11 G1642E,
923 14
406 12 N406K, N406S,
252 7
411 6 V411M,
243 11
932 11
1647 14
257 9
931 15
1646 11