SCN5A Variant A110T Detail

We estimate the penetrance of LQTS for SCN5A A110T around 17% and the Brugada syndrome penetrance around 10%. SCN5A A110T was found in a total of 5 carriers in 1 papers and/or in gnomAD: 0 had Brugada syndrome, 1 had LQTS. A110T is present in 4 alleles in gnomAD. A110T has been functionally characterized in 1 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 A110T around 17% (1/15) and the Brugada syndrome penetrance around 10% (1/15).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density BrS (%) Penetrance Density LQT3 (%)
-3.54 1 -1.09 0.953 14 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
23631430 2013 1 1 0 0
LITERATURE, COHORT, AND GNOMAD: - 5 4 1 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.

Functional Data

Peak and late/persistent current are relative to wildtype (100% being no different from wildtype). V0.5 act/inact are the voltages at which half of the maximal current is reached during an activation and inactivation protocol, each is in units of mV and relative to wildtype.
PubMed ID Year Cell Type Peak Current (%WT) V1/2 Act. (mV) V1/2 Inact. (mV) Late/Persistent Current (%WT)
23631430 2013

A110T 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
95 15 V95I, V95L,
96 14
97 14
98 13
99 13
100 12
101 11 T101I,
102 11
103 10
104 9 R104G, R104Q, R104W,
105 8
106 8 S106T,
107 7
108 5
109 4 N109K,
110 0 A110T,
111 4
112 5 Y112C,
113 7 V113I, V113A,
114 8
115 8 S115G,
116 9
117 10
118 11
119 11 P119S, P119L,
120 12
121 13 R121W, R121Q,
122 13
123 14 A123G, A123V,
124 14 A124D,
125 15 V125L,