SCN5A Variant Q990P Detail

We estimate the penetrance of LQTS for SCN5A Q990P around 6% and the Brugada syndrome penetrance around 7%. SCN5A Q990P was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. Q990P is not present in gnomAD. Q990P has been functionally characterized in 0 papers. This residue is located in a Non_Hotspot region for Brugada syndrome and a Non_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 Q990P around 6% (0/10) and the Brugada syndrome penetrance around 7% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.455 3 5
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.

Q990P 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
975 15 R975Q, R975W,
976 14
977 14
978 13
979 13 D979H,
980 12
981 11 C981F,
982 11 C982R,
983 10 G983D,
984 9
985 8
986 8 R986L, R986Q, R986W,
987 7
988 5 R988W, R988Q,
989 4
990 0
991 4 K991E, K991T,
992 5
993 7 A993T, A993S,
994 8 A994V, A994T,
995 8 L995F,
996 9 A996T,
997 10 A997S, A997D, A997T,
998 11
999 11 G999D,
1000 12 Q1000X, Q1000L, p.Gln1000del,
1001 13
1002 13 c.3005-3012delCCAGCTGG, P1002S,
1003 14
1004 14 C1004R,
1005 15 I1005T, I1005V,