rs773420384

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_ModerateBS1_SupportingBS2

The NM_004082.5(DCTN1):​c.59C>T​(p.Ala20Val) variant causes a missense change. The variant allele was found at a frequency of 0.0000144 in 1,458,150 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. A20A) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.000014 ( 0 hom. )

Consequence

DCTN1
NM_004082.5 missense

Scores

2
17

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 3.80

Publications

1 publications found
Variant links:
Genes affected
DCTN1 (HGNC:2711): (dynactin subunit 1) This gene encodes the largest subunit of dynactin, a macromolecular complex consisting of 10 subunits ranging in size from 22 to 150 kD. Dynactin binds to both microtubules and cytoplasmic dynein. Dynactin is involved in a diverse array of cellular functions, including ER-to-Golgi transport, the centripetal movement of lysosomes and endosomes, spindle formation, chromosome movement, nuclear positioning, and axonogenesis. This subunit interacts with dynein intermediate chain by its domains directly binding to dynein and binds to microtubules via a highly conserved glycine-rich cytoskeleton-associated protein (CAP-Gly) domain in its N-terminus. Alternative splicing of this gene results in multiple transcript variants encoding distinct isoforms. Mutations in this gene cause distal hereditary motor neuronopathy type VIIB (HMN7B) which is also known as distal spinal and bulbar muscular atrophy (dSBMA). [provided by RefSeq, Oct 2008]
DCTN1 Gene-Disease associations (from GenCC):
  • amyotrophic lateral sclerosis type 1
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
  • neuronopathy, distal hereditary motor, type 7B
    Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
  • Perry syndrome
    Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics
  • amyotrophic lateral sclerosis
    Inheritance: AD Classification: MODERATE Submitted by: ClinGen
  • distal hereditary motor neuropathy type 7
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -7 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.09575936).
BS1
Variant frequency is greater than expected in population mid. GnomAdExome4 allele frequency = 0.0000144 (21/1458150) while in subpopulation MID AF = 0.000706 (4/5662). AF 95% confidence interval is 0.000241. There are 0 homozygotes in GnomAdExome4. There are 13 alleles in the male GnomAdExome4 subpopulation. Median coverage is 32. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
BS2
High AC in GnomAdExome4 at 21 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
DCTN1NM_004082.5 linkc.59C>T p.Ala20Val missense_variant Exon 2 of 32 ENST00000628224.3 NP_004073.2 Q14203-1Q6MZZ3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
DCTN1ENST00000628224.3 linkc.59C>T p.Ala20Val missense_variant Exon 2 of 32 5 NM_004082.5 ENSP00000487279.2 Q14203-1E7EX90

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000121
AC:
3
AN:
247772
AF XY:
0.0000223
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000164
GnomAD4 exome
AF:
0.0000144
AC:
21
AN:
1458150
Hom.:
0
Cov.:
32
AF XY:
0.0000179
AC XY:
13
AN XY:
725676
show subpopulations
African (AFR)
AF:
0.0000597
AC:
2
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.0000580
AC:
5
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
49860
Middle Eastern (MID)
AF:
0.000706
AC:
4
AN:
5662
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1111982
Other (OTH)
AF:
0.0000828
AC:
5
AN:
60360
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.482
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.0000868
Hom.:
0
Bravo
AF:
0.0000151
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Neuronopathy, distal hereditary motor, type 7B Uncertain:2
Apr 27, 2019
Genomic Research Center, Shahid Beheshti University of Medical Sciences
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Perry syndrome Uncertain:2
Jan 12, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Apr 27, 2019
Genomic Research Center, Shahid Beheshti University of Medical Sciences
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Neuronopathy, distal hereditary motor, type 7B;C1862939:Amyotrophic lateral sclerosis type 1;C1868594:Perry syndrome Uncertain:1
Aug 27, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 20 of the DCTN1 protein (p.Ala20Val). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with DCTN1-related conditions. ClinVar contains an entry for this variant (Variation ID: 337098). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.083
BayesDel_addAF
Benign
-0.12
T
BayesDel_noAF
Benign
-0.41
CADD
Benign
20
DANN
Benign
0.94
DEOGEN2
Benign
0.086
T;.;T;.;T;.;.;T;T;.;T;T;.;T
Eigen
Benign
-0.40
Eigen_PC
Benign
-0.20
FATHMM_MKL
Uncertain
0.92
D
LIST_S2
Benign
0.77
T;T;T;T;.;T;T;T;T;T;.;T;T;.
M_CAP
Benign
0.010
T
MetaRNN
Benign
0.096
T;T;T;T;T;T;T;T;T;T;T;T;T;T
MetaSVM
Benign
-0.91
T
MutationAssessor
Benign
-0.69
N;N;.;.;.;N;.;.;.;.;.;.;.;.
PhyloP100
3.8
PrimateAI
Uncertain
0.54
T
PROVEAN
Benign
-0.40
N;N;.;N;N;N;N;N;N;N;N;N;N;D
REVEL
Benign
0.15
Sift
Benign
0.33
T;T;.;T;T;T;T;T;T;T;T;T;T;.
Sift4G
Benign
0.37
T;T;T;T;T;T;.;.;T;.;T;T;T;.
Polyphen
0.0
B;.;.;.;.;.;.;.;.;.;.;.;.;.
Vest4
0.13
MutPred
0.16
Loss of helix (P = 0.1299);Loss of helix (P = 0.1299);.;.;.;Loss of helix (P = 0.1299);.;.;.;.;.;.;.;.;
MVP
0.79
MPC
0.58
ClinPred
0.078
T
GERP RS
5.0
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.2
Varity_R
0.019
gMVP
0.48
Mutation Taster
=92/8
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs773420384; hg19: chr2-74605347; COSMIC: COSV62621689; COSMIC: COSV62621689; API