X-100407806-A-C

Position:

• chrX-100407806-A-C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_001184880.2(PCDH19):​c.792T>G​(p.Asp264Glu) variant causes a missense change involving the alteration of a non-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 Uncertain significance (★).

• Frequency: Genomes: not found (cov: 24)
• Consequence: PCDH19 NM_001184880.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.48

Genes affected

PCDH19 (HGNC:14270): (protocadherin 19) The protein encoded by this gene is a member of the delta-2 protocadherin subclass of the cadherin superfamily. The encoded protein is thought to be a calcium-dependent cell-adhesion protein that is primarily expressed in the brain. Mutations in this gene on human chromosome X are associated with sporadic infantile epileptic encephalopathy and to a female-restricted form of epilepsy (EFMR; also known as PCDH19RE). Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2017]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.984

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PCDH19	NM_001184880.2	c.792T>G	p.Asp264Glu	missense_variant	1/6	ENST00000373034.8	NP_001171809.1
PCDH19	NM_001105243.2	c.792T>G	p.Asp264Glu	missense_variant	1/5		NP_001098713.1
PCDH19	NM_020766.3	c.792T>G	p.Asp264Glu	missense_variant	1/5		NP_065817.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PCDH19	ENST00000373034.8	c.792T>G	p.Asp264Glu	missense_variant	1/6	1	NM_001184880.2	ENSP00000362125.4
PCDH19	ENST00000255531.8	c.792T>G	p.Asp264Glu	missense_variant	1/5	1		ENSP00000255531.7
PCDH19	ENST00000420881.6	c.792T>G	p.Asp264Glu	missense_variant	1/5	1		ENSP00000400327.2

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 24

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy, 9 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 15, 2018

This sequence change replaces aspartic acid with glutamic acid at codon 264 of the PCDH19 protein (p.Asp264Glu). The aspartic acid residue is highly conserved and there is a small physicochemical difference between aspartic acid and glutamic acid. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. 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, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with PCDH19-related disease. This variant is not present in population databases (ExAC no frequency). A different missense substitution at this codon (p.Asp264His) has been reported in two individuals affected with seizures and intellectual disability (PMID: 22946748, 27527380). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.49	.;T;.
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.93	D;D;D
M_CAP	Pathogenic	0.55	D
MetaRNN	Pathogenic	0.98	D;D;D
MetaSVM	Uncertain	0.51	D
MutationAssessor	Pathogenic	4.4	H;H;H
PrimateAI	Uncertain	0.78	T
PROVEAN	Uncertain	-3.7	D;D;D
REVEL	Pathogenic	0.81
Sift	Uncertain	0.0010	D;D;D
Sift4G	Uncertain	0.0040	D;D;D
Polyphen		1.0, 1.0	.;D;D
Vest4		0.95
MutPred		0.90		Gain of disorder (P = 0.1738);Gain of disorder (P = 0.1738);Gain of disorder (P = 0.1738);
MVP		1.0
MPC		2.3
ClinPred		1.0	D
GERP RS		4.0
Varity_R		0.98
gMVP		0.97

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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

Other links and lift over

dbSNP: rs373181586; hg19: chrX-99662804;