2-74370974-C-G

Variant names:

• chr2-74370974-C-G
• rs757238618
• NM_004082.5:c.843+5G>C

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 4P and 8B. PP3_Strong BS1 BS2

The NM_004082.5(DCTN1):​c.843+5G>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000821 in 1,461,468 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000082 (0 hom.)
• Consequence: DCTN1 NM_004082.5 splice_region, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.43
• Publications: 0 publications found

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

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• BS1: Variant frequency is greater than expected in population sas. GnomAdExome4 allele frequency = 0.00000821 (12/1461468) while in subpopulation SAS AF = 0.000139 (12/86226). AF 95% confidence interval is 0.00008. There are 0 homozygotes in GnomAdExome4. There are 7 alleles in the male GnomAdExome4 subpopulation. Median coverage is 33. This position passed quality control check.
• BS2: High AC in GnomAdExome4 at 12 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DCTN1	NM_004082.5	c.843+5G>C		splice_region_variant, intron_variant	Intron 9 of 31	ENST00000628224.3	NP_004073.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DCTN1	ENST00000628224.3	c.843+5G>C		splice_region_variant, intron_variant	Intron 9 of 31	5	NM_004082.5	ENSP00000487279.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000319 AC: 8 AN: 250878 AF XY: 0.0000368

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: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000821 AC: 12 AN: 1461468 Hom.: 0 Cov.: 33 AF XY: 0.00000963 AC XY: 7 AN XY: 727048

African (AFR) AF: 0.00 AC: 0 AN: 33474

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: 39700

South Asian (SAS) AF: 0.000139 AC: 12 AN: 86226

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53230

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5590

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60376

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.49
CADD	Pathogenic	26
DANN	Benign	0.91
PhyloP100		2.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.99
SpliceAI score (max)		0.56		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.56		Position offset: 14

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

Other links and lift over

dbSNP: rs757238618; hg19: chr2-74598101;