4-83469053-C-T

Position:

• chr4-83469053-C-T

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP6

The NM_139076.3(ABRAXAS1):​c.575G>A​(p.Ser192Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000548 in 1,460,946 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. S192S) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000055 (0 hom.)
• Consequence: ABRAXAS1 NM_139076.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: -0.0340

Genes affected

ABRAXAS1 (HGNC:25829): (abraxas 1, BRCA1 A complex subunit) This gene encodes a protein that binds to the C-terminal repeats of breast cancer 1 (BRCA1) through a phospho-SXXF motif. The encoded protein recruits ubiquitin interaction motif containing 1 protein to BRCA1 protein and is required for DNA damage resistance, DNA repair, and cell cycle checkpoint control. Pseudogenes of this gene are found on chromosomes 3 and 8. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2016]

MRPS18C (HGNC:16633): (mitochondrial ribosomal protein S18C) Mammalian mitochondrial ribosomal proteins are encoded by nuclear genes and help in protein synthesis within the mitochondrion. Mitochondrial ribosomes (mitoribosomes) consist of a small 28S subunit and a large 39S subunit. They have an estimated 75% protein to rRNA composition compared to prokaryotic ribosomes, where this ratio is reversed. Another difference between mammalian mitoribosomes and prokaryotic ribosomes is that the latter contain a 5S rRNA. Among different species, the proteins comprising the mitoribosome differ greatly in sequence, and sometimes in biochemical properties, which prevents easy recognition by sequence homology. This gene encodes a 28S subunit protein that belongs to the ribosomal protein S18P family. The encoded protein is one of three that has significant sequence similarity to bacterial S18 proteins. The primary sequences of the three human mitochondrial S18 proteins are no more closely related to each other than they are to the prokaryotic S18 proteins. Pseudogenes corresponding to this gene are found on chromosomes 8p, 12p, 15q, and 22q. [provided by RefSeq, Jul 2008]

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=0.036838263).
• BP6: Variant 4-83469053-C-T is Benign according to our data. Variant chr4-83469053-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 411327.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Likely_benign=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ABRAXAS1	NM_139076.3	c.575G>A	p.Ser192Asn	missense_variant	6/9	ENST00000321945.12
ABRAXAS1	NM_001345962.2	c.248G>A	p.Ser83Asn	missense_variant	5/8
ABRAXAS1	XR_001741334.3	n.603G>A		non_coding_transcript_exon_variant	6/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ABRAXAS1	ENST00000321945.12	c.575G>A	p.Ser192Asn	missense_variant	6/9	1	NM_139076.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251390 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135868

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: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000548 AC: 80 AN: 1460946 Hom.: 0 Cov.: 30 AF XY: 0.0000578 AC XY: 42 AN XY: 726782

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000683

Gnomad4 OTH exome AF: 0.0000498

GnomAD4 genome Cov.: 32

Bravo AF: 0.0000113

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 01, 2022

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 output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The asparagine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. ClinVar contains an entry for this variant (Variation ID: 411327). This variant has not been reported in the literature in individuals affected with ABRAXAS1-related conditions. This variant is present in population databases (rs368006283, gnomAD 0.003%). This sequence change replaces serine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 192 of the ABRAXAS1 protein (p.Ser192Asn). -

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 25, 2024

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.096
BayesDel_addAF	Benign	-0.41	T
BayesDel_noAF	Benign	-0.76
CADD	Benign	6.7
DANN	Benign	0.79
DEOGEN2	Benign	0.0016	T;.;T;.
Eigen	Benign	-0.92
Eigen_PC	Benign	-0.80
FATHMM_MKL	Benign	0.033	N
LIST_S2	Benign	0.61	T;T;T;T
M_CAP	Benign	0.0062	T
MetaRNN	Benign	0.037	T;T;T;T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.29	T
PROVEAN	Benign	-1.2	N;N;.;.
REVEL	Benign	0.035
Sift	Benign	0.44	T;T;.;.
Sift4G	Benign	0.54	T;T;T;T
Polyphen		0.0010	B;.;.;.
Vest4		0.18
MVP		0.22
MPC		0.096
ClinPred		0.023	T
GERP RS		1.7
Varity_R		0.044
gMVP		0.34

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs368006283; hg19: chr4-84390206;