SCN5A Variant D1550H Detail

We estimate the penetrance of LQTS for SCN5A D1550H around 5% and the Brugada syndrome penetrance around 21%. SCN5A D1550H was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. D1550H is not present in gnomAD. D1550H has been functionally characterized in 0 papers. This residue is located in a Mild_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 (2 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 D1550H around 5% (0/10) and the Brugada syndrome penetrance around 21% (2/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.916 22 2
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 13 0 2 - -
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.

D1550H 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
277 7
271 13 L271V,
266 14 L266H,
276 11 L276P, L276Q,
348 15 P348A,
270 10 Q270K,
360 13
279 14
1552 7 Q1552R, Q1552L,
355 11 F355I, F355C,
1549 5
278 11 H278D, H278R,
1556 12
356 6 D356N,
1557 12 I1557V,
361 13
343 7
384 15 S384T,
354 10
1546 14 M1546T,
1545 14
1550 0
1560 14 L1560F,
357 9
272 11
274 6 G274C,
273 5
1553 10 S1553R,
269 9
345 11
275 9 N275K,
347 11
1548 9 E1548K, G1548K,
351 13 G351S, G351V, G351D, G351C,
1555 15 E1555K,
265 15 A265V,
358 13
342 13
1551 4 D1551Y, D1551N,
346 12 E346X, E346G, E346D, E346K,
359 13 p.A359PfsX12, A359T,
1547 12 V1547L,
1554 12
344 10 A344S,
352 15 Y352C,
268 12 G268S,
353 14 T353I,
1623 14 c.4867delC, R1623X, R1623Q, R1623L,