rs1556388997

Positions:

• chrX-63697129-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001353921.2(ARHGEF9):​c.578A>G​(p.Glu193Gly) 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 Uncertain significance (★).

• Frequency: Genomes: not found (cov: 22)
• Consequence: ARHGEF9 NM_001353921.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.48

Genes affected

ARHGEF9 (HGNC:14561): (Cdc42 guanine nucleotide exchange factor 9) The protein encoded by this gene is a Rho-like GTPase that switches between the active (GTP-bound) state and inactive (GDP-bound) state to regulate CDC42 and other genes. This brain-specific protein also acts as an adaptor protein for the recruitment of gephyrin and together these proteins facilitate receceptor recruitement in GABAnergic and glycinergic synapses. Defects in this gene are the cause of startle disease with epilepsy (STHEE), also known as hyperekplexia with epilepsy, as well as several other types of cognitive disability. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.869

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ARHGEF9	NM_001353921.2	c.578A>G	p.Glu193Gly	missense_variant	4/10	ENST00000671741.2	NP_001340850.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ARHGEF9	ENST00000671741.2	c.578A>G	p.Glu193Gly	missense_variant	4/10		NM_001353921.2	ENSP00000500715	A1

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 22

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy, 8 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 28, 2017

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 ARHGEF9-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glutamic acid with glycine at codon 186 of the ARHGEF9 protein (p.Glu186Gly). The glutamic acid residue is highly conserved and there is a moderate physicochemical difference between glutamic acid and glycine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.51
BayesDel_addAF	Pathogenic	0.29	D
BayesDel_noAF	Pathogenic	0.19
CADD	Uncertain	25
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.52	D;T;.;T;T;T;T;T;T;.;.;T;.;T;T;.;T;.;T;T;.;.;T
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D;D;D;D;.;D;.;.;.;D;D;.;D;.;.;D;.;D;D;D;D;D;D
M_CAP	Pathogenic	0.55	D
MetaRNN	Pathogenic	0.87	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Benign	-0.33	T
MutationAssessor	Benign	1.4	L;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-4.8	D;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;D;.;.;.;.;.;.
REVEL	Uncertain	0.61
Sift	Uncertain	0.016	D;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;D;.;.;.;.;.;.
Sift4G	Uncertain	0.025	D;D;D;.;.;.;.;.;.;D;D;D;.;.;.;.;D;D;.;.;.;.;T
Polyphen		0.95	P;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.
Vest4		0.70
MutPred		0.55		Loss of stability (P = 0.0113);.;Loss of stability (P = 0.0113);.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;.;Loss of stability (P = 0.0113);.;.;.;
MVP		0.94
MPC		2.0
ClinPred		0.99	D
GERP RS		5.7
Varity_R		0.70
gMVP		0.82

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: rs1556388997; hg19: chrX-62917009;