rs1060502607
Variant summary
Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM1PM2PP3_ModeratePP5_Very_Strong
The NM_005184.4(CALM3):c.286G>C(p.Asp96His) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).
Frequency
Consequence
NM_005184.4 missense, splice_region
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 14 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD4 exome Cov.: 32
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Long QT syndrome 1 Pathogenic:1
This sequence change replaces aspartic acid with histidine at codon 96 of the CALM3 protein (p.Asp96His). The aspartic acid residue is highly conserved and there is a moderate physicochemical difference between aspartic acid and histidine. It also falls at the first nucleotide of exon 5 of the CALM3 coding sequence. This variant has been observed to be de novo in an individual with clinical features of CALM3-related disease (Invitae), and reported in the literature in an unrelated individual with long QT syndrome (PMID: 28491681). ClinVar contains an entry for this variant (Variation ID: 409870). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies. This variant is not present in population databases (ExAC no frequency). There are three different genes that encode calmodulin (CALM1, CALM2, and CALM3) that all have the same amino acid sequence, which suggests that changes in one version of the gene would have a similar effect on other versions of the gene (PMID: 26969752) A different missense substitution at this codon in CALM2 (p.Asp96Val) has been determined to be pathogenic (PMID: 23388215, 24563457, 24816216, 24958779). This suggests that the aspartic acid residue is critical for CALM3 protein function and that other missense substitutions affecting this residue may also be pathogenic. For these reasons, this variant has been classified as Pathogenic. -
Long QT syndrome 16 Pathogenic:1
Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a likely mechanism of disease in this gene and is associated with long QT syndrome 16 (MIM# 618782). (I) 0107 - This gene is associated with autosomal dominant disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from aspartic acid to histidine. (I) 0251 - This variant is heterozygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0502 - Missense variant with conflicting in silico predictions and uninformative conservation. (I) 0603 - Missense variant in a region that is highly intolerant to missense variation (high constraint region in DECIPHER). This variant is also a binding site within the EF-hand III domain pair (DECIPHER, PMID: 30574507). (SP) 0710 - Another missense variant comparable to the one identified in this case has inconclusive previous evidence for pathogenicity. The p.(Asp96Gly) variant has been identified in one individual with LQTS and classified as a VUS (PMID: 30847666). (I) 0802 - This variant has moderate previous evidence of pathogenicity in unrelated individuals. This variant has been classified once as pathogenic by a clinical diagnostic laboratory (ClinVar). This variant has also been reported in three young children with severe LQTS and/or fetal bradycardia including a female patient from Hong Kong who was internally confirmed to be de novo for the variant (PMIDs: 28491681, 30530868, 31535183). (SP) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1207 - Parental origin of the variant is unresolved. The variant is not maternally inherited (by segregation testing). However, the proband's father has not been tested for the variant and it is unclear if the variant is de novo or paternally inherited. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at