chrX-55023799-T-C

Variant summary

Our verdict is Benign. The variant received -13 ACMG points: 0P and 13B. BP4_StrongBP6BS1BS2

The NM_000032.5(ALAS2):​c.373A>G​(p.Ile125Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000048 in 1,208,599 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 12 hemizygotes in GnomAD. In-silico tool predicts a benign outcome for this variant. 15/23 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.00029 ( 0 hom., 7 hem., cov: 22)
Exomes 𝑓: 0.000024 ( 0 hom. 5 hem. )

Consequence

ALAS2
NM_000032.5 missense

Scores

2
15

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: 1.51

Publications

0 publications found
Variant links:
Genes affected
ALAS2 (HGNC:397): (5'-aminolevulinate synthase 2) The product of this gene specifies an erythroid-specific mitochondrially located enzyme. The encoded protein catalyzes the first step in the heme biosynthetic pathway. Defects in this gene cause X-linked pyridoxine-responsive sideroblastic anemia. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2008]
ALAS2 Gene-Disease associations (from GenCC):
  • X-linked erythropoietic protoporphyria
    Inheritance: XL Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet
  • X-linked sideroblastic anemia 1
    Inheritance: XL Classification: STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -13 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.017120868).
BP6
Variant X-55023799-T-C is Benign according to our data. Variant chrX-55023799-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 434119.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000289 (32/110621) while in subpopulation AFR AF = 0.00105 (32/30342). AF 95% confidence interval is 0.000767. There are 0 homozygotes in GnomAd4. There are 7 alleles in the male GnomAd4 subpopulation. Median coverage is 22. This position passed quality control check.
BS2
High Hemizygotes in GnomAd4 at 7 XL gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
ALAS2NM_000032.5 linkc.373A>G p.Ile125Val missense_variant Exon 4 of 11 ENST00000650242.1 NP_000023.2
ALAS2NM_001037968.4 linkc.376+919A>G intron_variant Intron 4 of 10 NP_001033057.1
ALAS2NM_001037967.4 linkc.304+919A>G intron_variant Intron 3 of 9 NP_001033056.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
ALAS2ENST00000650242.1 linkc.373A>G p.Ile125Val missense_variant Exon 4 of 11 NM_000032.5 ENSP00000497236.1

Frequencies

GnomAD3 genomes
AF:
0.000262
AC:
29
AN:
110572
Hom.:
0
Cov.:
22
show subpopulations
Gnomad AFR
AF:
0.000958
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.00
GnomAD2 exomes
AF:
0.000115
AC:
21
AN:
182721
AF XY:
0.0000446
show subpopulations
Gnomad AFR exome
AF:
0.00160
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000237
AC:
26
AN:
1097978
Hom.:
0
Cov.:
30
AF XY:
0.0000138
AC XY:
5
AN XY:
363342
show subpopulations
African (AFR)
AF:
0.000871
AC:
23
AN:
26401
American (AMR)
AF:
0.00
AC:
0
AN:
35199
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
19385
East Asian (EAS)
AF:
0.00
AC:
0
AN:
30204
South Asian (SAS)
AF:
0.00
AC:
0
AN:
54076
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
40505
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4135
European-Non Finnish (NFE)
AF:
0.00000119
AC:
1
AN:
841986
Other (OTH)
AF:
0.0000434
AC:
2
AN:
46087
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.454
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
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:
0.000289
AC:
32
AN:
110621
Hom.:
0
Cov.:
22
AF XY:
0.000213
AC XY:
7
AN XY:
32917
show subpopulations
African (AFR)
AF:
0.00105
AC:
32
AN:
30342
American (AMR)
AF:
0.00
AC:
0
AN:
10348
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
2627
East Asian (EAS)
AF:
0.00
AC:
0
AN:
3497
South Asian (SAS)
AF:
0.00
AC:
0
AN:
2583
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
5886
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
215
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
52934
Other (OTH)
AF:
0.00
AC:
0
AN:
1509
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.501
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
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:
0.000104
Hom.:
4
Bravo
AF:
0.000268
ESP6500AA
AF:
0.00156
AC:
6
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.000148
AC:
18

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not specified Uncertain:1
Feb 15, 2017
Genetic Services Laboratory, University of Chicago
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Inborn genetic diseases Uncertain:1
Sep 09, 2024
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.373A>G (p.I125V) alteration is located in exon 4 (coding exon 3) of the ALAS2 gene. This alteration results from a A to G substitution at nucleotide position 373, causing the isoleucine (I) at amino acid position 125 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

X-linked sideroblastic anemia 1 Uncertain:1
Dec 19, 2023
Johns Hopkins Genomics, Johns Hopkins University
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This ALAS2 missense variant (rs143995220) is rare (<0.1%) in a large population dataset (gnomAD v4.0.0: 58/1208599 total alleles; 0.005%; 12 hemizygotes, no homozygotes). It has been reported in ClinVar (Variation ID 434119), but has not been reported in the literature, to our knowledge. Two bioinformatic tools queried predict that this substitution would be tolerated, and the isoleucine residue at this position is evolutionarily conserved across many of the species assessed. We consider the clinical significance of c.373A>G in ALAS2 to be uncertain at this time. -

not provided Benign:1
Jan 06, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.065
BayesDel_addAF
Benign
-0.39
T
BayesDel_noAF
Benign
-0.36
CADD
Benign
6.0
DANN
Benign
0.55
DEOGEN2
Benign
0.20
T;T;.;.
FATHMM_MKL
Benign
0.083
N
LIST_S2
Benign
0.64
.;T;T;T
M_CAP
Uncertain
0.12
D
MetaRNN
Benign
0.017
T;T;T;T
MetaSVM
Uncertain
-0.046
T
MutationAssessor
Benign
1.1
L;L;.;.
PhyloP100
1.5
PrimateAI
Benign
0.38
T
PROVEAN
Benign
0.090
.;N;.;.
REVEL
Benign
0.22
Sift
Benign
0.30
.;T;.;.
Sift4G
Benign
0.42
.;T;.;.
Polyphen
0.0
B;B;.;.
Vest4
0.063
MVP
0.58
MPC
0.42
ClinPred
0.027
T
GERP RS
4.2
Varity_R
0.086
gMVP
0.59
Mutation Taster
=99/1
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.20
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.20
Position offset: -42

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs143995220; hg19: chrX-55050232; API