SCN5A Variant M748R Detail

We estimate the penetrance of LQTS for SCN5A M748R around 16% and the Brugada syndrome penetrance around 12%. SCN5A M748R was found in a total of 0 carriers in 0 papers and/or in gnomAD: 0 had Brugada syndrome, 0 had LQTS. M748R is not present in gnomAD. M748R 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 M748R around 16% (0/10) and the Brugada syndrome penetrance around 12% (1/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
NA NA NA 0.911 7 17
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.

M748R has 31 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
737 10
747 6 E747A,
811 14 c.2435_2436+3delTGGTAinsCGCCT, R811G, R811H,
735 12 A735E, A735T, A735V,
733 7 F733L,
751 6 V751F, V751I,
754 11
736 9 L736P,
732 11
741 10 p.M741_T742delinsI ,
808 15 R808H, R808C, R808P,
745 5
734 12 M734V, c.2201dupT,
756 11
730 11 N730K,
750 8 Q750R,
753 9
729 11 p.L729del,
749 4
757 15
746 8 E746K,
743 9
748 0 M748I,
738 13
744 7
742 9 T742A,
752 7 G752R,
755 11
740 14 p.N740del,
731 13 T731I,
726 15