2-74376741-C-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PVS1_ModerateBS1_SupportingBS2

The NM_004082.5(DCTN1):c.414+1G>A variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.0000623 in 1,604,832 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000072 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000061 ( 1 hom. )

Consequence

DCTN1
NM_004082.5 splice_donor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:3B:1

Conservation

PhyloP100: 5.95

Publications

2 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

DCTN1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.0054730256 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.8, offset of 3, new splice context is: atgGTgtgt. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.

BS1

Variant frequency is greater than expected in population amr. GnomAd4 allele frequency = 0.0000723 (11/152232) while in subpopulation AMR AF = 0.000393 (6/15286). AF 95% confidence interval is 0.00017. There are 0 homozygotes in GnomAd4. There are 7 alleles in the male GnomAd4 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 GnomAd4 at 11 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DCTN1	NM_004082.5 link	c.414+1G>A		splice_donor_variant, intron_variant	Intron 5 of 31	ENST00000628224.3	NP_004073.2	Q14203-1Q6MZZ3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DCTN1	ENST00000628224.3 link	c.414+1G>A		splice_donor_variant, intron_variant	Intron 5 of 31	5	NM_004082.5	ENSP00000487279.2		Q14203-1E7EX90

Frequencies

GnomAD3 genomes

AF:

0.0000723

AC:

AN:

152232

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000393

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00143

GnomAD2 exomes

AF:

0.0000635

AC:

AN:

236150

AF XY:

0.0000473

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000304

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000374

Gnomad OTH exome

AF:

0.000172

GnomAD4 exome

AF:

0.0000613

AC:

AN:

1452600

Hom.:

Cov.:

AF XY:

0.0000568

AC XY:

AN XY:

721322

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33410

American (AMR)

AF:

0.000415

AC:

AN:

43400

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25860

East Asian (EAS)

AF:

0.00

AC:

AN:

39484

South Asian (SAS)

AF:

0.00

AC:

AN:

84104

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52702

Middle Eastern (MID)

AF:

0.000174

AC:

AN:

5738

European-Non Finnish (NFE)

AF:

0.0000551

AC:

AN:

1107796

Other (OTH)

AF:

0.000133

AC:

AN:

60106

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.468

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Exome Hom

Variant carriers

<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:

0.0000723

AC:

AN:

152232

Hom.:

Cov.:

AF XY:

0.0000941

AC XY:

AN XY:

74372

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41452

American (AMR)

AF:

0.000393

AC:

AN:

15286

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5204

South Asian (SAS)

AF:

0.00

AC:

AN:

4836

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68036

Other (OTH)

AF:

0.00143

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.452

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.000102

Hom.:

Bravo

AF:

0.000189

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.000259

AC:

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:3Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Neuronopathy, distal hereditary motor, type 7B;C1862939:Amyotrophic lateral sclerosis type 1;C1868594:Perry syndrome

Uncertain:2

Jan 12, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change affects a donor splice site in intron 5 of the DCTN1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), however the current clinical and genetic evidence is not sufficient to establish whether loss-of-function variants in DCTN1 cause disease. This variant is present in population databases (rs576198476, gnomAD 0.03%). Disruption of this splice site has been observed in individual(s) with clinical features of distal hereditary motor neuropathy (PMID: 33369814). ClinVar contains an entry for this variant (Variation ID: 282607). 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. -

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

See cases

Pathogenic:1

Apr 05, 2019

Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

ACMG classification criteria: PVS1, PM2, PP3 -

not provided

Uncertain:1

Aug 13, 2015

Eurofins Ntd Llc (ga)

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Inborn genetic diseases

Benign:1

Dec 22, 2020

Ambry Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This alteration is classified as likely 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.23

BayesDel_noAF

Pathogenic

0.40

CADD

Pathogenic

(source)

DANN

Uncertain

0.99

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.96

FATHMM_MKL

Pathogenic

0.98

PhyloP100

5.9

GERP RS

5.1

Mutation Taster

=0/100

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.91

Splicevardb

1.0

SpliceAI score (max)

0.060

Details are displayed if max score is > 0.2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over