3-9803984-C-T

Position:

• chr3-9803984-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PS1_Moderate PM2 PP3_Strong PP5

The NM_005718.5(ARPC4):​c.472C>T​(p.Arg158Cys) 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. 11/19 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in same amino acid change has been previously reported as Likely pathogenicin UniProt.

• Frequency: Genomes: not found (cov: 33)
• Consequence: ARPC4 NM_005718.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1 O:1
• Conservation: PhyloP100: 7.57

Genes affected

ARPC4 (HGNC:707): (actin related protein 2/3 complex subunit 4) This gene encodes one of seven subunits of the human Arp2/3 protein complex. This complex controls actin polymerization in cells and has been conserved throughout eukaryotic evolution. This gene encodes the p20 subunit, which is necessary for actin nucleation and high-affinity binding to F-actin. Alternative splicing results in multiple transcript variants. Naturally occurring read-through transcription exists between this gene and the downstream tubulin tyrosine ligase-like family, member 3 (TTLL3), which results in the production of a fusion protein. [provided by RefSeq, Nov 2010]

ARPC4-TTLL3 (HGNC:38830): (ARPC4-TTLL3 readthrough) This locus represents naturally occurring read-through transcription between the neighboring ARPC4 (actin related protein 2/3 complex, subunit 4) and TTLL3 (tubulin tyrosine ligase-like family, member 3) genes. The read-through transcript encodes a fusion protein that shares sequence identity with each individual gene product. [provided by RefSeq, Nov 2010]

ARPC4 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PS1: Transcript NM_005718.5 (ARPC4) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in UniProt
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.984
• PP5: Variant 3-9803984-C-T is Pathogenic according to our data. Variant chr3-9803984-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1339815.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, not_provided=1, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
ARPC4	NM_005718.5	c.472C>T	p.Arg158Cys	missense_variant	5/6	ENST00000397261.8	NP_005709.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
ARPC4	ENST00000397261.8	c.472C>T	p.Arg158Cys	missense_variant	5/6	1	NM_005718.5	ENSP00000380431.2
ARPC4-TTLL3	ENST00000397256.5	c.330+2228C>T		intron_variant		5		ENSP00000380427.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Developmental delay, language impairment, and ocular abnormalities Pathogenic:2

Likely pathogenic, criteria provided, single submitter	curation	SIB Swiss Institute of Bioinformatics	Mar 03, 2024	This variant is interpreted for Developmental delay, language impairment, and ocular abnormalities, autosomal dominant. The following ACMG Tag(s) were applied: Absent from controls (or at extremely low frequency if recessive) in gnomAD (PM2). Prevalence in affected individuals statistically increased over controls (PS4-moderate).De novo data (PM6). Multiple lines of computational evidence support a deleterious effect on the gene or gene product (PP3). -
Pathogenic, no assertion criteria provided	literature only	OMIM	Nov 30, 2022	- -

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 07, 2021

The c.529C>T (p.R177C) alteration is located in exon 5 (coding exon 5) of the ARPC4 gene. This alteration results from a C to T substitution at nucleotide position 529, causing the arginine (R) at amino acid position 177 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Other:1

not provided, no classification provided

phenotyping only

GenomeConnect, ClinGen

-

Variant interpreted as Uncertain significance and reported on 08-20-2019 by Lab or GTR ID 26957. GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.47
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.51	.;D;T;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	0.99	D;D;D;D
M_CAP	Benign	0.059	D
MetaRNN	Pathogenic	0.98	D;D;D;D
MetaSVM	Uncertain	0.51	D
MutationAssessor	Pathogenic	3.6	.;H;.;.
PROVEAN	Pathogenic	-7.6	D;D;.;D
REVEL	Pathogenic	0.82
Sift	Pathogenic	0.0	D;D;.;D
Sift4G	Pathogenic	0.0	D;D;D;D
Polyphen		1.0	.;D;.;.
Vest4		0.81
MutPred		0.91		.;Loss of MoRF binding (P = 0.0087);.;.;
MVP		0.84
MPC		2.6
ClinPred		1.0	D
GERP RS		6.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.58
gMVP		0.98

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr3-9845668;