SCN5A Variant L938Q Detail

We estimate the penetrance of LQTS for SCN5A L938Q around 19% and the Brugada syndrome penetrance around 15%. SCN5A L938Q was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L938Q is not present in gnomAD. L938Q has been functionally characterized in 0 papers. This residue is located in a Mild_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 (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 L938Q around 19% (0/10) and the Brugada syndrome penetrance around 15% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.98 12 22
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 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.

L938Q has 72 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
939 5 L939F,
937 5
1765 13
839 9 L839P,
842 11
943 9 S943N,
1340 14 V1340I,
1457 12
1455 13
1472 14 N1472S, p.N1472del,
1461 9 T1461S,
409 12 L409P, L409V,
1333 15
1344 15 F1344S, F1344L,
836 13 V836M,
417 12
934 5
1458 12 S1458Y,
933 9
1471 11
935 6 L935P,
412 12 V412D,
1470 10
1464 6 L1464P, c.4389_4396delCCTCTTTA,
1466 9 c.4396_4397insG,
944 11
830 14
833 13 G833R,
1769 14
415 15 A415T,
1768 14 I1768V,
940 7 S940N,
1341 14
1468 10 V1468A, V1468F,
831 9
1462 11
420 13
938 0
840 13
942 5
843 13 T843A,
1456 12
930 12 c.2787+17_2787+18insACACACACACACACACACACACA, c.2788-6C>T,
1459 11 c.4376_4379delTCTT,
834 12 N834D,
1772 14 L1772V,
827 14
1460 7 F1460L,
837 13
239 14 I239V , I239V,
410 14 A410V,
929 15
416 10 Y416C,
413 11 A413T, A413E,
841 14 p.N841TfsX2, N841K,
941 6 S941N, S941F,
1337 12
846 15 L846R,
936 6
238 14
838 10
1465 11 p.F1465_L1480dup,
1467 7
1761 15 c.5280delG, L1761H, L1761F,
1469 12 I1469V,
829 14
932 10
832 10
835 9 S835L, S835A,
828 11 L828V,
931 11
1463 7 N1463Y,