19-7440011-C-T

Position:

• chr19-7440011-C-T

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BS1_Supporting

The NM_001367823.1(ARHGEF18):​c.968-333C>T variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000107 in 1,398,250 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.000011 (0 hom.)
• Consequence: ARHGEF18 NM_001367823.1 intron
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.19

Genes affected

ARHGEF18 (HGNC:17090): (Rho/Rac guanine nucleotide exchange factor 18) Rho GTPases are GTP binding proteins that regulate a wide spectrum of cellular functions. These cellular processes include cytoskeletal rearrangements, gene transcription, cell growth and motility. Activation of Rho GTPases is under the direct control of guanine nucleotide exchange factors (GEFs). The protein encoded by this gene is a guanine nucleotide exchange factor and belongs to the Rho GTPase GEF family. Family members share a common feature, a Dbl (DH) homology domain followed by a pleckstrin (PH) homology domain. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Nov 2018]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.026199818).
• BS1: Variant frequency is greater than expected in population sas. gnomad4_exome allele frequency = 0.0000107 (15/1398250) while in subpopulation SAS AF= 0.000189 (15/79172). AF 95% confidence interval is 0.000116. There are 0 homozygotes in gnomad4_exome. There are 11 alleles in male gnomad4_exome subpopulation. Median coverage is 39. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ARHGEF18	NM_001367823.1	c.968-333C>T		intron_variant		ENST00000668164.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ARHGEF18	ENST00000668164.2	c.968-333C>T		intron_variant			NM_001367823.1	A2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.00000641 AC: 1 AN: 156034 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 82770

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000440

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000107 AC: 15 AN: 1398250 Hom.: 0 Cov.: 39 AF XY: 0.0000160 AC XY: 11 AN XY: 689560

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.000189

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

Asia WGS AF: 0.00202 AC: 7 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 09, 2022

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 24 of the ARHGEF18 protein (p.Ala24Val). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with ARHGEF18-related conditions. ClinVar contains an entry for this variant (Variation ID: 1355728). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.21	T
BayesDel_noAF	Benign	-0.55
CADD	Benign	20
DANN	Uncertain	1.0
Eigen	Benign	-0.98
Eigen_PC	Benign	-0.93
FATHMM_MKL	Benign	0.075	N
LIST_S2	Benign	0.50	T
M_CAP	Benign	0.0067	T
MetaRNN	Benign	0.026	T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.31	T
PROVEAN	Benign	-0.75	N
REVEL	Benign	0.033
Sift	Benign	1.0	T
Sift4G	Uncertain	0.020	D
Vest4		0.028
MutPred		0.18		Gain of helix (P = 0.0078);
MVP		0.28
MPC		0.30
ClinPred		0.14	T
GERP RS		1.3
gMVP		0.19

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: rs1291208215; hg19: chr19-7504897;