NM_000071.3:c.1479G>A

Variant summary

Our verdict is Benign. The variant received -7 ACMG points: 0P and 7B. BP4_StrongBP6BP7BS2_Supporting

The NM_000071.3(CBS):​c.1479G>A​(p.Thr493Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. In-silico tool predicts 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. T493T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0 ( 0 hom., cov: 0)
Exomes 𝑓: 0.00035 ( 2 hom. )
Failed GnomAD Quality Control

Consequence

CBS
NM_000071.3 synonymous

Scores

2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:6

Conservation

PhyloP100: -2.33

Publications

1 publications found
Variant links:
Genes affected
CBS (HGNC:1550): (cystathionine beta-synthase) The protein encoded by this gene acts as a homotetramer to catalyze the conversion of homocysteine to cystathionine, the first step in the transsulfuration pathway. The encoded protein is allosterically activated by adenosyl-methionine and uses pyridoxal phosphate as a cofactor. Defects in this gene can cause cystathionine beta-synthase deficiency (CBSD), which can lead to homocystinuria. This gene is a major contributor to cellular hydrogen sulfide production. Multiple alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Feb 2016]
CBS Gene-Disease associations (from GenCC):
  • classic homocystinuria
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Orphanet, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, PanelApp Australia, ClinGen, Genomics England PanelApp

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -7 ACMG points.

BP4
Computational evidence support a benign effect (REVEL=0.012).
BP6
Variant 21-43056876-C-T is Benign according to our data. Variant chr21-43056876-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 212834.We mark this variant Likely_benign, oryginal submission is: [Conflicting_classifications_of_pathogenicity].
BP7
Synonymous conserved (PhyloP=-2.33 with no splicing effect.
BS2
High Homozygotes in GnomAdExome4 at 2 AR geneVariant has number of homozygotes lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CBSNM_000071.3 linkc.1479G>A p.Thr493Thr synonymous_variant Exon 16 of 17 ENST00000398165.8 NP_000062.1 P35520-1Q9NTF0

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CBSENST00000398165.8 linkc.1479G>A p.Thr493Thr synonymous_variant Exon 16 of 17 1 NM_000071.3 ENSP00000381231.4 P35520-1

Frequencies

GnomAD3 genomes
AF:
0.00
AC:
0
AN:
2474
Hom.:
0
Cov.:
0
Gnomad AFR
AF:
0.00
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:
0.000368
AC:
59
AN:
160528
AF XY:
0.000331
show subpopulations
Gnomad AFR exome
AF:
0.000220
Gnomad AMR exome
AF:
0.000239
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000858
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000676
Gnomad OTH exome
AF:
0.000443
GnomAD4 exome
AF:
0.000346
AC:
56
AN:
162074
Hom.:
2
Cov.:
0
AF XY:
0.000319
AC XY:
28
AN XY:
87886
show subpopulations
African (AFR)
AF:
0.000422
AC:
2
AN:
4734
American (AMR)
AF:
0.000157
AC:
2
AN:
12772
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3714
East Asian (EAS)
AF:
0.00
AC:
0
AN:
10710
South Asian (SAS)
AF:
0.000155
AC:
5
AN:
32332
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
6944
Middle Eastern (MID)
AF:
0.00157
AC:
1
AN:
638
European-Non Finnish (NFE)
AF:
0.000524
AC:
43
AN:
82044
Other (OTH)
AF:
0.000366
AC:
3
AN:
8186
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
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

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
Data not reliable, filtered out with message: AC0;AS_VQSR
AF:
0.00
AC:
0
AN:
2482
Hom.:
0
Cov.:
0
AF XY:
0.00
AC XY:
0
AN XY:
1250
African (AFR)
AF:
0.00
AC:
0
AN:
94
American (AMR)
AF:
0.00
AC:
0
AN:
1090
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
58
East Asian (EAS)
AF:
0.00
AC:
0
AN:
184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
150
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
98
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
20
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
734
Other (OTH)
AF:
0.00
AC:
0
AN:
42
Alfa
AF:
0.000238
Hom.:
0
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:6
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Benign:3
Feb 01, 2024
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

CBS: BP4, BP7 -

-
Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Classic homocystinuria Uncertain:2
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

-
Center for Genomics, Ann and Robert H. Lurie Children's Hospital of Chicago
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant has not been reported in the literature. This variant may be present in the general population, but population data for this variant is unreliable due to the presence of a highly homologous pseudogene. This variant is present in ClinVar, with classifications ranging from likely benign to variant of uncertain significance (Variation ID: 212834). This is a silent variant and does not change the amino acid, reducing the probability that this variant is disease causing. Splice prediction tools suggest that this variant may affect splicing, although further studies are needed to understand its impact. In summary, data on this variant is insufficient for disease classification. Therefore, the clinical significance of this variant is uncertain. However, we cannot rule out the possibility that this variant is present in the pseudogene rather than in the real protein-coding gene. -

not specified Benign:1
Aug 18, 2014
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Familial thoracic aortic aneurysm and aortic dissection Benign:1
Sep 19, 2016
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. -

HYPERHOMOCYSTEINEMIA, THROMBOTIC, CBS-RELATED Benign:1
Jan 27, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.47
CADD
Benign
0.076
DANN
Benign
0.65
PhyloP100
-2.3
Mutation Taster
=100/0
polymorphism

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

Other links and lift over

dbSNP: rs143225442; hg19: chr21-44476986; COSMIC: COSV61445315; COSMIC: COSV61445315; API