chr6-24301742-AT-A

Variant names:

• chr6-24301742-AT-A
• rs904944428
• NM_016356.5:c.529delA

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_016356.5(DCDC2):​c.529delA​(p.Ile177SerfsTer3) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: DCDC2 NM_016356.5 frameshift
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.780
• Publications: 4 publications found

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 Gene-Disease associations (from GenCC):

• ciliopathy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen, Ambry Genetics
• isolated neonatal sclerosing cholangitis

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
• nephronophthisis 19

  Inheritance: AR Classification: STRONG Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• hearing loss, autosomal recessive

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Senior-Boichis syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• nonsyndromic genetic hearing loss

  Inheritance: AR Classification: LIMITED Submitted by: ClinGen
• autosomal recessive nonsyndromic hearing loss 66

  Inheritance: Unknown, AR Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, Ambry Genetics

ACMG classification

Our verdict: Pathogenic. The variant received 10 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

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_016356.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	DCDC2	NM_016356.5	MANE Select	c.529delA	p.Ile177SerfsTer3	frameshift	Exon 4 of 10	NP_057440.2
	DCDC2	NM_001195610.2		c.529delA	p.Ile177SerfsTer3	frameshift	Exon 5 of 11	NP_001182539.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	DCDC2	ENST00000378454.8	TSL:1 MANE Select	c.529delA	p.Ile177SerfsTer3	frameshift	Exon 4 of 10	ENSP00000367715.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.78
Mutation Taster		=3/197	disease causing (fs/PTC)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs904944428; hg19: chr6-24301970; COSMIC: COSV101016141;