SCN5A Variant I900N Detail

We estimate the penetrance of LQTS for SCN5A I900N around 9% and the Brugada syndrome penetrance around 50%. SCN5A I900N was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. I900N is not present in gnomAD. I900N 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 (4 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 I900N around 9% (0/10) and the Brugada syndrome penetrance around 50% (4/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.926 75 8
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 11 0 4 - -
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.

I900N has 70 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
364 9
891 13 I891N, I891T,
890 12 I890T,
901 6 S901L, E901K,
919 9
363 8
896 13 C896S,
348 12 P348A,
895 14 L895F,
360 12
894 9 I894M,
355 14 F355I, F355C,
372 6
371 12 Q371E,
1711 14 c.5131delG,
361 13
904 5 W904X,
366 10
365 12
376 10 R376C, R376H,
354 13
897 9 G897R, G897E,
909 14
927 15 N927K, N927S,
369 14 M369K,
1422 13 M1422R,
1418 14
902 6
349 10 D349N,
373 7
898 8
893 9 R893H, R893C,
921 14
922 12 V922I,
362 13
911 15 G911E,
920 10
900 0
918 13
917 13 L917V, L917R,
913 15
916 10
912 13 Q912R,
347 14
906 10
351 12 G351D, G351S, G351V, G351C,
910 15 S910L,
878 14 R878C, R878L, R878H,
1421 14
374 12 W374G,
350 9 H350Q,
903 5 p.M903CfsX29,
367 6 R367C, R367L, R367H,
359 14 A359T, p.A359PfsX12,
370 10 T370M,
877 14
879 13 W879R,
923 11
905 9
375 12
352 10 Y352C,
915 11 C915R,
368 11
899 4
380 14
377 10
908 12
1419 13 K1419E,
353 10 T353I,
907 9