rs148968498
Variant summary
Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP6BS2
The NM_172201.2(KCNE2):c.80G>A(p.Arg27His) variant causes a missense change. The variant allele was found at a frequency of 0.0000446 in 1,614,144 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_172201.2 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -5 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
KCNE2 | NM_172201.2 | c.80G>A | p.Arg27His | missense_variant | Exon 2 of 2 | ENST00000290310.4 | NP_751951.1 | |
LOC105372791 | NR_188571.1 | n.729C>T | non_coding_transcript_exon_variant | Exon 2 of 3 | ||||
LOC105372791 | NR_188572.1 | n.729C>T | non_coding_transcript_exon_variant | Exon 2 of 2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000230 AC: 35AN: 152136Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000636 AC: 16AN: 251474Hom.: 0 AF XY: 0.0000368 AC XY: 5AN XY: 135910
GnomAD4 exome AF: 0.0000253 AC: 37AN: 1461890Hom.: 0 Cov.: 31 AF XY: 0.0000261 AC XY: 19AN XY: 727246
GnomAD4 genome AF: 0.000230 AC: 35AN: 152254Hom.: 0 Cov.: 32 AF XY: 0.000161 AC XY: 12AN XY: 74442
ClinVar
Submissions by phenotype
Atrial fibrillation, familial, 4;C3150953:Long QT syndrome 6 Uncertain:1
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not provided Uncertain:1
This variant was found in a 14 yo male with a history of V-fib cardiac arrest, WPW, atrial fibrillation, and LVNC found on cardiac MRI. He had genetic testing with the Invitae laboratory. The following 124 genes associated with heritable arrhythmia syndromes and cardiomyopathies were evaluated for sequence changes and exonic deletions/duplications: ABCC9, ACADVL, ACTC1, ACTN2, AGL, AKAP9, ALMS1, ANK2, ANKRD1, BAG3, CACNA1C, CACNA2D1, CACNB2, CALM1, CALM2, CALM3, CALR3, CASQ2, CAV1, CAV3, CHRM2, CPT2, CRYAB, CSRP3, CTF1, CTNNA3, DES, DMD, DNAJC19, DOLK, DSC2, DSG2, DSP, DTNA, ELAC2, EMD, EYA4, FHL1, FHL2, FKRP, FKTN, FLNC, GAA, GATA4, GATA6, GATAD1, GJA1, GJA5, GLA, GPD1L, HCN4, ILK, JPH2, JUP, KCNA5, KCND3, KCNE1, KCNE2, KCNE3, KCNE5, KCNH2, KCNJ2, KCNJ5, KCNJ8, KCNK3, KCNQ1, LAMA4, LAMP2, LDB3, LMNA, LRRC10, MTO1, MYBPC3, MYH6, MYH7, MYL2, MYL3, MYL4, MYLK2, MYOM1, MYOZ2, MYPN, NEBL, NEXN, NKX2-5, NKX2-6, NPPA, PDLIM3, PKP2, PLEKHM2, PLN, PRDM16, PRKAG2, RAF1, RANGRF, RBM20, RYR2, SCN10A, SCN1B, SCN2B, SCN3B, SCN4B, SCN5A, SGCD, SLC22A5, SLMAP, SNTA1, TAZ, TBX5, TCAP, TGFB3, TMEM43, TMEM70, TMPO, TNNC1, TNNI3, TNNT2, TPM1, TRDN, TRPM4, TTN, TTR, TXNRD2, VCL. The following gene was evaluated for sequence changes only: SDHA. One variant was reported: p.Arg27His (R27H; c.80G>A) in exon 2 of the KCNE2 gene (NM_172201.1; ENST00000290310) Chromosome location: 21:35742857 G / A Based on the information reviewed below, including its appreciable frequency in the broader population, particularly in people with African ancestry such as our patient, we classify it as a Variant of Uncertain Significance (VUS), probably benign, concluding that there is not sufficient evidence for its pathogenicity to warrant using it for diagnosis or predictive genetic testing. This variant has previously been reported in two individuals suspected to have LQTS. Their ethnicity is not reported. There is no published segregation data. The variant was reported in 1 individual in the Familion compendium, which includes 2500 patients referred for clinical long QT genetic testing (Kapplinger et al 2009, PMID: 19716085). Of note, there is no phenotype data on this cohort confirming a diagnosis of LQTS, and genetic testing had a low yield of 36% (vs. 70% in cohorts with firm diagnoses of long QT). There is also a lack of clarity regarding which variants were seen alongside another variant (9% of the cohort had multiple variants). The Arg27His variant was also reported by Sauer and Marc-Aurele (2016) in a 19-day-old female neonate with documented VF and a QTc of 465 msec; the baby also had a second variant in KCNE2, Ile20Asn (which is absent from gnomAD and not yet reported to ClinVar by any genetic testing lab), apparently in trans—given that her mother tested positive only for Arg27His (PMID: 27465075). Her testing was done at Familion. This is a conservative amino acid change, resulting in the replacement of a positively-charged Arginine with a positively-charged Histidine. Arginine at this location is fairly highly conserved across ~100 vertebrate species, although Histidine is the default amino acid in at least 2 species, suggesting that this missense change is tolerated (in two other species it is a Serine or a Glutamine). There are no missense variants at nearby residues (+/- 10) currently listed in ClinVar as Likely Pathogenic or Pathogenic. According to the Invitae report, algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C25". These predictions have not been confirmed by published functional studies. This variant was reported online in 24 individuals in the gnomAD database, which includes variant calls on ~140,000 individuals of European, African, Latino, South Asian, Ashkenazi, and East Asian descent. Specifically, the variant was observed in 20/12,012 individuals with African ancestry like our patient ( -
Long QT syndrome Uncertain:1
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Cardiovascular phenotype Benign:1
This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Long QT syndrome 6 Benign:1
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Congenital long QT syndrome Other:1
This variant has been reported as associated with Long QT syndrome in the following publications (PMID:19716085). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at