SCN5A Variant Q987H Detail

We estimate the penetrance of LQTS for SCN5A Q987H around 9% and the Brugada syndrome penetrance around 8%. SCN5A Q987H was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. Q987H is not present in gnomAD. Q987H 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 Q987H around 9% (0/10) and the Brugada syndrome penetrance around 8% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.318 4 10
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.

Q987H has 31 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
972 15 c.2914_2923delTTTGTCAAGC,
973 14
974 14 K974D,
975 13 R975W, R975Q,
976 13
977 12
978 11
979 11 D979H,
980 10
981 9 C981F,
982 8 C982R,
983 8 G983D,
984 7
985 5
986 4 R986L, R986W, R986Q,
987 0
988 4 R988Q, R988W,
989 5
990 7
991 8 K991E, K991T,
992 8
993 9 A993T, A993S,
994 10 A994V, A994T,
995 11 L995F,
996 11 A996T,
997 12 A997S, A997D, A997T,
998 13
999 13 G999D,
1000 14 p.Gln1000del, Q1000L, Q1000X,
1001 14
1002 15 P1002S, c.3005-3012delCCAGCTGG,