Genetic Variant DCDC2:p.Ile177AsnfsTer20 (chr6-24301742-A-AT) – ACMG Classification: Pathogenic (18 pts)

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_016356.5(DCDC2):c.529dupA(p.Ile177AsnfsTer20) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,613,970 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

DCDC2
NM_016356.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 0.780

Variant links:

Genes affected

DCDC2 (HGNC:18141): (doublecortin domain containing 2) This gene encodes a doublecortin domain-containing family member. The doublecortin domain has been demonstrated to bind tubulin and enhance microtubule polymerization. This family member is thought to function in neuronal migration where it may affect the signaling of primary cilia. Mutations in this gene have been associated with reading disability (RD) type 2, also referred to as developmental dyslexia. Alternatively spliced transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jan 2013]

DCDC2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 6-24301742-A-AT is Pathogenic according to our data. Variant chr6-24301742-A-AT is described in ClinVar as [Pathogenic]. Clinvar id is 417769.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DCDC2	NM_016356.5 link	c.529dupA	p.Ile177AsnfsTer20	frameshift_variant	Exon 4 of 10	ENST00000378454.8	NP_057440.2
DCDC2	NM_001195610.2 link	c.529dupA	p.Ile177AsnfsTer20	frameshift_variant	Exon 5 of 11		NP_001182539.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DCDC2	ENST00000378454.8 link	c.529dupA	p.Ile177AsnfsTer20	frameshift_variant	Exon 4 of 10	1	NM_016356.5	ENSP00000367715.3		Q9UHG0-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152094

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251436

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135888

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 SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000123

AC:

AN:

1461876

Hom.:

Cov.:

AF XY:

0.0000124

AC XY:

AN XY:

727234

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000144

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152094

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74298

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000151

EpiCase

AF:

0.000109

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:2

Apr 11, 2017

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 18, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed at a significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 30078246, 27469900) -

Isolated neonatal sclerosing cholangitis

Pathogenic:1

Mar 28, 2017

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Autosomal recessive nonsyndromic hearing loss 66;C4479344:Isolated neonatal sclerosing cholangitis

Pathogenic:1

Oct 30, 2019

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in DCDC2 are known to be pathogenic (PMID: 25557784). This variant has been reported in siblings affected with neonatal sclerosing cholangitis (PMID: 27469900). ClinVar contains an entry for this variant (Variation ID: 417769). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Ile177Asnfs*20) in the DCDC2 gene. It is expected to result in an absent or disrupted protein product. -

Autosomal recessive nonsyndromic hearing loss 66;C4015542:Nephronophthisis 19;C4479344:Isolated neonatal sclerosing cholangitis

Pathogenic:1

Apr 23, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.030

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

Below is the list of publications found by LitVar. It may be empty.

6-24301742-AT-ATT

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over