chr6-131583831-G-A

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PM2PM5

The NM_000045.4(ARG1):​c.892G>A​(p.Ala298Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000434 in 1,614,002 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A298P) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

ARG1
NM_000045.4 missense

Scores

7
11

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.78

Publications

3 publications found
Variant links:
Genes affected
ARG1 (HGNC:663): (arginase 1) Arginase catalyzes the hydrolysis of arginine to ornithine and urea. At least two isoforms of mammalian arginase exist (types I and II) which differ in their tissue distribution, subcellular localization, immunologic crossreactivity and physiologic function. The type I isoform encoded by this gene, is a cytosolic enzyme and expressed predominantly in the liver as a component of the urea cycle. Inherited deficiency of this enzyme results in argininemia, an autosomal recessive disorder characterized by hyperammonemia. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2011]
MED23 (HGNC:2372): (mediator complex subunit 23) The activation of gene transcription is a multistep process that is triggered by factors that recognize transcriptional enhancer sites in DNA. These factors work with co-activators to direct transcriptional initiation by the RNA polymerase II apparatus. The protein encoded by this gene is a subunit of the CRSP (cofactor required for SP1 activation) complex, which, along with TFIID, is required for efficient activation by SP1. This protein is also a component of other multisubunit complexes e.g. thyroid hormone receptor-(TR-) associated proteins which interact with TR and facilitate TR function on DNA templates in conjunction with initiation factors and cofactors. This protein also acts as a metastasis suppressor. Several alternatively spliced transcript variants encoding different isoforms have been described for this gene. [provided by RefSeq, Jul 2012]
MED23 Gene-Disease associations (from GenCC):
  • intellectual disability, autosomal recessive 18
    Inheritance: AR Classification: STRONG, MODERATE, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
  • syndromic intellectual disability
    Inheritance: AR Classification: MODERATE Submitted by: ClinGen
  • autosomal recessive non-syndromic intellectual disability
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_000045.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr6-131583831-G-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 419034.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ARG1NM_000045.4 linkc.892G>A p.Ala298Thr missense_variant Exon 8 of 8 ENST00000368087.8 NP_000036.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ARG1ENST00000368087.8 linkc.892G>A p.Ala298Thr missense_variant Exon 8 of 8 1 NM_000045.4 ENSP00000357066.3

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152190
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.000478
GnomAD4 exome
AF:
0.00000342
AC:
5
AN:
1461812
Hom.:
0
Cov.:
31
AF XY:
0.00000275
AC XY:
2
AN XY:
727204
show subpopulations
African (AFR)
AF:
0.0000896
AC:
3
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39674
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111976
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152190
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74356
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41448
American (AMR)
AF:
0.0000654
AC:
1
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68032
Other (OTH)
AF:
0.000478
AC:
1
AN:
2090
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.0296732), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.400
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Arginase deficiency Uncertain:1
Jun 27, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 298 of the ARG1 protein (p.Ala298Thr). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with ARG1-related conditions. ClinVar contains an entry for this variant (Variation ID: 1021041). 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 tolerated. 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
AlphaMissense
Benign
0.14
BayesDel_addAF
Uncertain
0.075
D
BayesDel_noAF
Benign
-0.13
CADD
Benign
23
DANN
Uncertain
0.99
DEOGEN2
Benign
0.38
T;.;.
Eigen
Benign
0.14
Eigen_PC
Benign
0.22
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.81
T;T;T
M_CAP
Benign
0.035
D
MetaRNN
Uncertain
0.59
D;D;D
MetaSVM
Uncertain
-0.14
T
MutationAssessor
Uncertain
2.2
M;.;.
PhyloP100
4.8
PrimateAI
Benign
0.43
T
PROVEAN
Benign
0.19
N;N;.
REVEL
Uncertain
0.29
Sift
Benign
0.051
T;T;.
Sift4G
Benign
0.40
T;T;.
Vest4
0.12
ClinPred
0.93
D
GERP RS
5.1
Varity_R
0.38
gMVP
0.48
Mutation Taster
=60/40
polymorphism

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

Other links and lift over

dbSNP: rs755359126; hg19: chr6-131904971; API