SCN5A Variant L1608H Detail

We estimate the penetrance of LQTS for SCN5A L1608H around 17% and the Brugada syndrome penetrance around 19%. SCN5A L1608H was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. L1608H is not present in gnomAD. L1608H has been functionally characterized in 0 papers. This residue is located in a Mild_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 (1 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 L1608H around 17% (0/10) and the Brugada syndrome penetrance around 19% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.979 19 19
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 14 0 1 - -
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.

L1608H has 26 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
1600 11
1606 6 T1606I,
1610 7 D1610G,
1612 12
1615 14 Y1615X,
1572 15
1605 5 G1605D, c.4813+2_4813+5dupTGGG, c.4813+5insTGGG, c.4813+3_4813+6dupGGGT, G1605C,
1611 8 I1611V,
1616 9
1607 4
1599 13
1568 13
1617 10 p.F1617del,
1608 0
1565 13 L1565M,
1604 5 V1604M, c.4810+3_4810+6dupGGGT,
1602 9
1622 13
1618 13
1614 15
1601 10 L1601H,
1609 4 S1609L, S1609W,
1603 7 I1603F,
1598 15 V1598A,
1619 14 P1619L, P1619Q, c.4856delC,
1613 11 Q1613L, Q1613H,