rs587783535

Positions:

• chrX-111410167-G-A

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_001195553.2(DCX):​c.232C>T​(p.Arg78Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R78H) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 22)
• Consequence: DCX NM_001195553.2 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.81

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]

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrX-111410166-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 158443.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.939
• PP5: Variant X-111410167-G-A is Pathogenic according to our data. Variant chrX-111410167-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 158442.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DCX	NM_001195553.2	c.232C>T	p.Arg78Cys	missense_variant	2/7	ENST00000636035.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DCX	ENST00000636035.2	c.232C>T	p.Arg78Cys	missense_variant	2/7	2	NM_001195553.2	A1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 22

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Ectopic tissue Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Feb 08, 2013

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jul 15, 2022

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Arg78 amino acid residue in DCX. Other variant(s) that disrupt this residue have been observed in individuals with DCX-related conditions (PMID: 23365099), which suggests that this may be a clinically significant amino acid residue. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 158442). This missense change has been observed in individual(s) with agyria–pachygyria–subcortical band heterotopia spectrum (PMID: 23365099). In at least one individual the variant was observed to be de novo. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 78 of the DCX protein (p.Arg78Cys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.64	D
BayesDel_noAF	Pathogenic	0.68
CADD	Pathogenic	34
DANN	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Pathogenic	0.89	D
MetaRNN	Pathogenic	0.94	D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Pathogenic	0.87	D
Vest4		0.87, 0.90, 0.90
MVP		1.0
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.98
gMVP		0.95

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.32		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.32		Position offset: -5

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

Publications

LitVar

Other links and lift over

dbSNP: rs587783535; hg19: chrX-110653395; COSMIC: COSV57570498;