NM_004082.5:c.442C>T

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4BS1_SupportingBS2

The NM_004082.5(DCTN1):​c.442C>T​(p.Arg148Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000626 in 1,614,012 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R148G) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000066 ( 0 hom. )

Consequence

DCTN1
NM_004082.5 missense

Scores

12
7

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:1

Conservation

PhyloP100: 3.07

Publications

6 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: Likely_benign. The variant received -6 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.27709365).
BS1
Variant frequency is greater than expected in population nfe. GnomAdExome4 allele frequency = 0.0000664 (97/1461770) while in subpopulation NFE AF = 0.0000773 (86/1111968). AF 95% confidence interval is 0.0000641. There are 0 homozygotes in GnomAdExome4. There are 40 alleles in the male GnomAdExome4 subpopulation. Median coverage is 30. 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 97 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
DCTN1NM_004082.5 linkc.442C>T p.Arg148Trp missense_variant Exon 7 of 32 ENST00000628224.3 NP_004073.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
DCTN1ENST00000628224.3 linkc.442C>T p.Arg148Trp missense_variant Exon 7 of 32 5 NM_004082.5 ENSP00000487279.2

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152124
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000242
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000756
AC:
19
AN:
251420
AF XY:
0.0000589
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:
0.000158
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000664
AC:
97
AN:
1461770
Hom.:
0
Cov.:
30
AF XY:
0.0000550
AC XY:
40
AN XY:
727186
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.0000383
AC:
1
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86252
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53356
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000773
AC:
86
AN:
1111968
Other (OTH)
AF:
0.000132
AC:
8
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.468
Heterozygous variant carriers
0
4
9
13
18
22
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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
AF:
0.0000263
AC:
4
AN:
152242
Hom.:
0
Cov.:
32
AF XY:
0.0000537
AC XY:
4
AN XY:
74438
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41526
American (AMR)
AF:
0.00
AC:
0
AN:
15290
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10592
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.538
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome 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
Alfa
AF:
0.0000326
Hom.:
0
Bravo
AF:
0.0000416
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.000140
AC:
17
EpiCase
AF:
0.00
EpiControl
AF:
0.000119

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:4Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:1Benign:1
Mar 10, 2023
Mayo Clinic Laboratories, Mayo Clinic
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nov 16, 2017
Athena Diagnostics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
Nov 19, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: DCTN1 c.442C>T (p.Arg148Trp) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 7.6e-05 in 251420 control chromosomes (gnomAD). This frequency is not higher than the estimated maximum for a pathogenic variant in DCTN1 causing Amyotrophic lateral sclerosis type 1, allowing no conclusion about variant significance. c.442C>T has been reported in the literature in a cohort of individuals affected with motor neuron disease (MND) (Stockmann_2013). Authors of this study also reported experimental evidence evaluating an impact on protein function and demonstrated that this variant didn't affect the filamentous pattern of microtubules in non-neuronal cells (Stockmann_2013). The following publication have been ascertained in the context of this evaluation (PMID: 23143281). ClinVar contains an entry for this variant (Variation ID: 447238). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Neuronopathy, distal hereditary motor, type 7B Uncertain:1
Sep 06, 2019
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -

Neuronopathy, distal hereditary motor, type 7B;C1862939:Amyotrophic lateral sclerosis type 1;C1868594:Perry syndrome Uncertain:1
Sep 06, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 148 of the DCTN1 protein (p.Arg148Trp). This variant is present in population databases (rs148810193, gnomAD 0.01%). 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: 447238). 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. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.51
BayesDel_addAF
Benign
-0.0086
T
BayesDel_noAF
Uncertain
0.010
CADD
Pathogenic
31
DANN
Uncertain
1.0
DEOGEN2
Benign
0.28
T;.;T;.;.;T;.
Eigen
Uncertain
0.42
Eigen_PC
Uncertain
0.48
FATHMM_MKL
Uncertain
0.86
D
LIST_S2
Uncertain
0.97
D;D;D;D;D;.;D
M_CAP
Benign
0.061
D
MetaRNN
Benign
0.28
T;T;T;T;T;T;T
MetaSVM
Uncertain
-0.25
T
MutationAssessor
Uncertain
2.0
M;.;.;.;.;.;.
PhyloP100
3.1
PrimateAI
Uncertain
0.77
T
PROVEAN
Benign
-2.2
N;N;.;.;D;N;N
REVEL
Uncertain
0.31
Sift
Uncertain
0.0050
D;D;.;.;D;D;D
Sift4G
Benign
0.092
T;D;T;D;D;T;.
Polyphen
1.0
D;.;.;D;.;.;.
Vest4
0.52
MVP
0.89
MPC
0.88
ClinPred
0.22
T
GERP RS
5.1
Varity_R
0.14
gMVP
0.33
Mutation Taster
=76/24
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs148810193; hg19: chr2-74600066; COSMIC: COSV100720860; COSMIC: COSV100720860; API