chr1-77942158-T-TA
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 4P and 4B. PVS1_StrongBS2
The NM_144573.4(NEXN):c.1609_1610insA(p.Leu537TyrfsTer7) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000328 in 1,613,672 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. L537L) has been classified as Likely benign.
Frequency
Consequence
NM_144573.4 frameshift
Scores
Clinical Significance
Conservation
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ACMG classification
Our verdict: Uncertain_significance. The variant received 0 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152134Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000804 AC: 2AN: 248826 AF XY: 0.0000148 show subpopulations
GnomAD4 exome AF: 0.0000356 AC: 52AN: 1461538Hom.: 0 Cov.: 31 AF XY: 0.0000413 AC XY: 30AN XY: 727066 show subpopulations
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152134Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74322 show subpopulations
ClinVar
Submissions by phenotype
Dilated cardiomyopathy 1CC;C3151267:Hypertrophic cardiomyopathy 20 Uncertain:2
This sequence change creates a premature translational stop signal (p.Leu537Tyrfs*7) in the NEXN gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 139 amino acid(s) of the NEXN protein. This variant is present in population databases (rs779350415, gnomAD 0.0009%). This premature translational stop signal has been observed in individual(s) with left ventricular noncompaction (PMID: 33500567). ClinVar contains an entry for this variant (Variation ID: 283614). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
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not specified Uncertain:1
Variant classified as Uncertain Significance - Favor Pathogenic. The p.Leu537fs variant in NEXN has not been previously reported in individuals with cardiomyopa thy, but has been identified in 1/66208 European chromosomes by the Exome Aggreg ation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs779350415). This variant is predicted to cause a frameshift, which alters the protein?s amino ac id sequence beginning at position 537 and leads to a premature termination codon 7 amino acids downstream. Although the severe nature of this change increases t he likelihood that the variant is pathogenic, the NEXN gene has not been widely studied and the spectrum of variants leading to disease is not well-defined. Los s of NEXN function has been shown to cause DCM in zebrafish; however, it remains unclear if one or both copies of the gene need to be affected to cause disease (Hassel 2009, Wang 2010). In summary, while there is some suspicion for a pathog enic role, the clinical significance of the p.Leu537fs variant is uncertain. -
not provided Uncertain:1
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Long QT syndrome Uncertain:1
This variant has been identified as part of our research program. Refer to the 'condition' field for the phenotype of the proband identified with this variant. For further information please feel free to contact us. -
Cardiovascular phenotype Uncertain:1
The c.1609_1610insA variant, located in coding exon 11 of the NEXN gene, results from an insertion of one nucleotide at position 1609, causing a translational frameshift with a predicted alternate stop codon (p.L537Yfs*7). This alteration occurs at the 3' terminus of theNEXN gene, is not expected to trigger nonsense-mediated mRNAdecay, and impacts the last 20% of the protein. The exact functional effect of this alteration is unknown. This variant was reported in an individual in a dilated cardiomyopathy (DCM) cohort, but clinical details were limited (Mazzarotto F et al. Circulation, 2020 Feb;141:387-398). Based on the available evidence, the clinical significance of this variant remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at