rs778201974
Variant summary
Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PP3_ModerateBP6BS2
The NM_004082.5(DCTN1):c.2633A>G(p.Tyr878Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000266 in 1,614,058 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_004082.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Likely_benign. Variant got -3 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152168Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000278 AC: 7AN: 251472Hom.: 0 AF XY: 0.0000368 AC XY: 5AN XY: 135904
GnomAD4 exome AF: 0.0000267 AC: 39AN: 1461890Hom.: 0 Cov.: 32 AF XY: 0.0000358 AC XY: 26AN XY: 727244
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152168Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74344
ClinVar
Submissions by phenotype
Inborn genetic diseases Uncertain:1
The p.Y878C variant (also known as c.2633A>G), located in coding exon 23 of the DCTN1 gene, results from an A to G substitution at nucleotide position 2633. The tyrosine at codon 878 is replaced by cysteine, an amino acid with highly dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Neuronopathy, distal hereditary motor, type 7B;C1862939:Amyotrophic lateral sclerosis type 1;C1868594:Perry syndrome Uncertain:1
This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 878 of the DCTN1 protein (p.Tyr878Cys). This variant is present in population databases (rs778201974, gnomAD 0.006%). This missense change has been observed in individual(s) with amyotrophic lateral sclerosis (ALS) (PMID: 23143281). ClinVar contains an entry for this variant (Variation ID: 568956). 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. Experimental studies have shown that this missense change does not substantially affect DCTN1 function (PMID: 23143281). 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. -
not specified Benign:1
Variant summary: DCTN1 c.2633A>G (p.Tyr878Cys) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.7e-05 in 1614058 control chromosomes. The observed variant frequency is approximately 26-fold of the estimated maximal expected allele frequency for a pathogenic variant in DCTN1 causing Neuronopathy, distal hereditary motor, type 7B phenotype (1e-06). c.2633A>G has been reported in the literature in cohorts of individuals affected with Amyotrophic lateral sclerosis, without strong evidence for causality (e.g. Stockmann_2013, Pensato_2020, Grassano_2022). These reports do not provide unequivocal conclusions about association of the variant with disease. At least one publication reports experimental evidence evaluating an impact on protein function and found the variant did not result in substantial changes to cellular morphology in vitro (Stockmann_2013). The following publications have been ascertained in the context of this evaluation (PMID: 35896380, 23143281, 32028661). ClinVar contains an entry for this variant (Variation ID: 568956). Based on the evidence outlined above, the variant was classified as likely benign. -
Neuronopathy, distal hereditary motor, type 7B Benign:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -
Perry syndrome Benign:1
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at