SCN5A Variant Q1476R Detail

We estimate the penetrance of LQTS for SCN5A Q1476R around 76% and the Brugada syndrome penetrance around 7%. SCN5A Q1476R was found in a total of 3 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 3 had LQTS. Q1476R is not present in gnomAD. Q1476R has been functionally characterized in 1 papers. This residue is located in a Non_Hotspot region for Brugada syndrome and a 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 (3 with LQTS). These data combined with observations of carriers lead us to estimate the LQTS penetrance for SCN5A Q1476R around 76% (6/13) and the Brugada syndrome penetrance around 7% (0/13).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-3.82 0.888 -2.22 0.943 3 88
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
24098284 2013 3 3 0 0
LITERATURE, COHORT, AND GNOMAD: - 3 0 3 0 -
VARIANT FEATURES ALONE: - 15 12 3 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.

Functional Data

Peak and late/persistent current are relative to wildtype (100% being no different from wildtype). V0.5 act/inact are the voltages at which half of the maximal current is reached during an activation and inactivation protocol, each is in units of mV and relative to wildtype.
PubMed ID Year Cell Type Peak Current (%WT) V1/2 Act. (mV) V1/2 Inact. (mV) Late/Persistent Current (%WT)
24098284 2013 tsA201 93 1.6 6.5 206

Q1476R has 48 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
1328 10 V1328M,
1659 14
1480 6 c.4438-1C>T, c.4437+5G>A,
1773 11
1653 15
1472 7 p.N1472del, N1472S,
1315 14
1777 15 V1777M, V1777L,
1487 14 M1487K, M1487L,
1320 12 M1320I,
1333 14
1492 14
1656 12
1477 6 K1477N,
1471 11
1470 11
1478 7 K1478E,
1660 14 I1660V, I1660S,
1329 9 G1329S,
1769 11
1766 11 M1766L, M1766V, M1766T,
1319 10 G1319V,
1774 13 c.5321_5324dupACTT, N1774D,
1479 4
1473 6 F1473C, F1473S,
1468 13 V1468F, V1468A,
1474 7
1324 9
1481 9 G1481V, G1481E, G1481R,
1327 10
1318 13
1330 11 A1330P, A1330T, A1330D,
1772 15 L1772V,
1321 10 R1321K,
1323 8 V1323G,
1770 11 I1770V,
1482 10
1322 5 c.3963+4A>G, c.3963+2T>C,
1326 6 A1326S,
1332 14 P1332L, P1332Q,
1467 15
1476 0 Q1476X, Q1476R,
1484 11
1331 14 I1331V,
1475 6 p.Q1475NfsX6, Q1475L,
1469 11 I1469V,
1483 13 Q1483H,
1325 6 N1325S,