rs148810193

chr2-74372939-G-Achr2-74372939-G-Cchr2-74372939-G-T

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 0P and 5B. BP4 BS2

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
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: 3.07

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]

ACMG classification

Verdict is Likely_benign. Variant got -5 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.27709365).
• BS2: High AC in GnomAdExome at 19 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DCTN1	NM_004082.5	c.442C>T	p.Arg148Trp	missense_variant	7/32	ENST00000628224.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DCTN1	ENST00000628224.3	c.442C>T	p.Arg148Trp	missense_variant	7/32	5	NM_004082.5	A1

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152124 Hom.: 0 Cov.: 32

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

GnomAD3 exomes AF: 0.0000756 AC: 19 AN: 251420 Hom.: 0 AF XY: 0.0000589 AC XY: 8 AN XY: 135880

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 SAS exome AF: 0.0000327

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

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.0000383

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.0000187

Gnomad4 NFE exome AF: 0.0000773

Gnomad4 OTH exome AF: 0.000132

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152242 Hom.: 0 Cov.: 32 AF XY: 0.0000537 AC XY: 4 AN XY: 74438

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000319 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:3 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1 Benign:1

Likely benign, criteria provided, single submitter	clinical testing	Athena Diagnostics	Nov 16, 2017	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Mar 10, 2023	- -

Neuronopathy, distal hereditary motor, type 7B Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

Sep 06, 2019

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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 13, 2024

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;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
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

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

LitVar

Other links and lift over

dbSNP: rs148810193; hg19: chr2-74600066; COSMIC: COSV100720860; COSMIC: COSV100720860;