SCN5A Variant I1521R Detail

We estimate the penetrance of LQTS for SCN5A I1521R around 6% and the Brugada syndrome penetrance around 31%. SCN5A I1521R was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I1521R is not present in gnomAD. I1521R has been functionally characterized in 0 papers. This residue is located in a 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 (3 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 I1521R around 6% (0/10) and the Brugada syndrome penetrance around 31% (3/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.85 42 4
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 12 0 3 - -
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.

I1521R has 39 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
1523 7 D1523N,
1521 0 I1521K, I1521T,
1585 14 Y1585C,
1527 10 K1527R,
1576 8
1517 8
1525 7 V1525A, V1525M,
1519 5
1572 13
1570 15 I1570V, p.I1570dup, p.1570_F1571insI,
1584 15
1515 11 N1515S, c.4542+15G>A,
1529 14
1574 11 c.4719C>T, E1574K,
1524 5 I1524T,
1512 9 R1512Q, R1512W, R1512L,
1530 10
1586 13
1514 12 L1514M,
1518 5
1592 15
1578 9 c.4732_4733dupAA,
1531 13
1573 10
1526 9 T1526P,
1516 11 L1516sp,
1583 11 R1583C, R1583H,
1580 6
1534 15
1511 13
1581 6 A1581S,
1513 9
1582 9 L1582P,
1579 9 L1579fsX53,
1522 6
1520 6
1577 5
1575 11 C1575S,
1510 13