chrX-111400988-AC-A

Variant names:

• chrX-111400988-AC-A
• rs1556401725
• NM_001195553.2:c.705+1delG

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_001195553.2(DCX):​c.705+1delG variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: DCX NM_001195553.2 splice_donor, intron
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.91
• Publications: 0 publications found

Genes affected

DCX (HGNC:2714): (doublecortin) This gene encodes a member of the doublecortin family. The protein encoded by this gene is a cytoplasmic protein and contains two doublecortin domains, which bind microtubules. In the developing cortex, cortical neurons must migrate over long distances to reach the site of their final differentiation. The encoded protein appears to direct neuronal migration by regulating the organization and stability of microtubules. In addition, the encoded protein interacts with LIS1, the regulatory gamma subunit of platelet activating factor acetylhydrolase, and this interaction is important to proper microtubule function in the developing cortex. Mutations in this gene cause abnormal migration of neurons during development and disrupt the layering of the cortex, leading to epilepsy, cognitive disability, subcortical band heterotopia ("double cortex" syndrome) in females and lissencephaly ("smooth brain" syndrome) in males. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2010]

DCX Gene-Disease associations (from GenCC):

• lissencephaly spectrum disorders

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen
• lissencephaly type 1 due to doublecortin gene mutation

  Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P
• subcortical band heterotopia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.30971843 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5.7, offset of 0 (no position change), new splice context is: acaGTaggt. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-111400988-AC-A is Pathogenic according to our data. Variant chrX-111400988-AC-A is described in ClinVar as Pathogenic. ClinVar VariationId is 434903.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001195553.2. 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
	DCX	NM_001195553.2	MANE Select	c.705+1delG		splice_donor intron	N/A	NP_001182482.1
	DCX	NM_000555.3		c.948+1delG		splice_donor intron	N/A	NP_000546.2
	DCX	NM_001369370.1		c.705+1delG		splice_donor intron	N/A	NP_001356299.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	DCX	ENST00000636035.2	TSL:2 MANE Select	c.705+1delG		splice_donor intron	N/A	ENSP00000490614.1
	DCX	ENST00000358070.10	TSL:1	c.885+1delG		splice_donor intron	N/A	ENSP00000350776.6
	DCX	ENST00000356220.8	TSL:5	c.705+1delG		splice_donor intron	N/A	ENSP00000348553.4

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Subcortical laminar heterotopia, X-linked Pathogenic:1

Jun 20, 2017

Genetic Services Laboratory, University of Chicago

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.9
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.99		Position offset: 3
DS_DL_spliceai		1.0		Position offset: 2

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

Other links and lift over

dbSNP: rs1556401725; hg19: chrX-110644216;