SCN5A Variant L939H Detail

We estimate the penetrance of LQTS for SCN5A L939H around 15% and the Brugada syndrome penetrance around 10%. SCN5A L939H was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L939H is not present in gnomAD. L939H 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 (0 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A L939H around 15% (0/10) 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 0.935 3 16
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 15 0 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.

L939H has 68 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 12 M414V,
939 0 L939F,
937 7
1773 11
1765 13
839 13 L839P,
842 14
943 7 S943N,
1472 12 p.N1472del, N1472S,
1771 14 I1771T,
1461 13 T1461S,
418 14 E418K,
409 10 L409P, L409V,
1333 15
417 9
934 9
933 10
1471 7
935 7 L935P,
412 11 V412D,
1470 7
1464 9 c.4389_4396delCCTCTTTA, L1464P,
1466 8 c.4396_4397insG,
1776 12
944 10
1769 11
415 12 A415T,
1768 12 I1768V,
940 5 S940N,
1473 13 F1473C, F1473S,
1468 9 V1468A, V1468F,
831 12
1462 14
420 11
1474 11
938 5
942 7
419 15 Q419X,
930 14 c.2787+17_2787+18insACACACACACACACACACACACA, c.2788-6C>T,
1459 15 c.4376_4379delTCTT,
834 15 N834D,
1772 10 L1772V,
1460 12 F1460L,
239 15 I239V, I239V ,
410 11 A410V,
242 15 A242D,
1770 15 I1770V,
416 9 Y416C,
413 8 A413E, A413T,
941 7 S941N, S941F,
1337 15
936 5
238 15
838 13
1465 12 p.F1465_L1480dup,
1467 6
1775 14 F1775V, p.F1775LfsX15,
421 13
1475 14 p.Q1475NfsX6, Q1475L,
1469 10 I1469V,
406 14 N406S, N406K,
411 13 V411M,
932 11
832 14
835 13 S835L, S835A,
828 14 L828V,
931 13
1463 10 N1463Y,