rs147474549

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PP2PP3_Strong

The NM_000071.3(CBS):​c.400G>C​(p.Gly134Arg) variant causes a missense change. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G134A) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000030 ( 1 hom., cov: 14)
Exomes 𝑓: 0.000011 ( 2 hom. )
Failed GnomAD Quality Control

Consequence

CBS
NM_000071.3 missense

Scores

10
7
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:2

Conservation

PhyloP100: 6.84

Publications

3 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: Likely_pathogenic. The variant received 7 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 12 uncertain in NM_000071.3
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 107 curated pathogenic missense variants (we use a threshold of 10). The gene has 4 curated benign missense variants. Gene score misZ: 0.8318 (below the threshold of 3.09). Trascript score misZ: NaN (below the threshold of 3.09). GenCC associations: The gene is linked to classic homocystinuria.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.991

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CBSNM_000071.3 linkc.400G>C p.Gly134Arg missense_variant Exon 5 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.400G>C p.Gly134Arg missense_variant Exon 5 of 17 1 NM_000071.3 ENSP00000381231.4 P35520-1

Frequencies

GnomAD3 genomes
AF:
0.0000304
AC:
3
AN:
98808
Hom.:
1
Cov.:
14
show subpopulations
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:
0.0000599
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000399
AC:
1
AN:
250778
AF XY:
0.00000737
show subpopulations
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000881
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
Data not reliable, filtered out with message: AS_VQSR
AF:
0.0000111
AC:
11
AN:
986700
Hom.:
2
Cov.:
15
AF XY:
0.0000119
AC XY:
6
AN XY:
503732
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
16396
American (AMR)
AF:
0.00
AC:
0
AN:
42030
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
20706
East Asian (EAS)
AF:
0.00
AC:
0
AN:
38078
South Asian (SAS)
AF:
0.00
AC:
0
AN:
72002
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
37442
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
3802
European-Non Finnish (NFE)
AF:
0.0000154
AC:
11
AN:
712598
Other (OTH)
AF:
0.00
AC:
0
AN:
43646
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.639
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
Data not reliable, filtered out with message: AS_VQSR
AF:
0.0000304
AC:
3
AN:
98808
Hom.:
1
Cov.:
14
AF XY:
0.00
AC XY:
0
AN XY:
47830
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
17100
American (AMR)
AF:
0.00
AC:
0
AN:
11394
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
2574
East Asian (EAS)
AF:
0.00
AC:
0
AN:
4436
South Asian (SAS)
AF:
0.00
AC:
0
AN:
3212
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
7792
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
194
European-Non Finnish (NFE)
AF:
0.0000599
AC:
3
AN:
50080
Other (OTH)
AF:
0.00
AC:
0
AN:
1338
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.675
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
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Classic homocystinuria Uncertain:1
Jul 27, 2020
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

HYPERHOMOCYSTEINEMIA, THROMBOTIC, CBS-RELATED Uncertain:1
Jan 22, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 134 of the CBS protein (p.Gly134Arg). This variant is present in population databases (rs147474549, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with CBS-related conditions. ClinVar contains an entry for this variant (Variation ID: 538695). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CBS protein function with a positive predictive value of 95%. 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
0.24
BayesDel_addAF
Pathogenic
0.48
D
BayesDel_noAF
Pathogenic
0.45
CADD
Uncertain
23
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.99
D;D;D;D;.
Eigen
Uncertain
0.63
Eigen_PC
Uncertain
0.45
FATHMM_MKL
Uncertain
0.90
D
LIST_S2
Pathogenic
0.99
.;.;.;D;D
M_CAP
Pathogenic
0.93
D
MetaRNN
Pathogenic
0.99
D;D;D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
4.0
H;H;H;H;.
PhyloP100
6.8
PrimateAI
Uncertain
0.65
T
PROVEAN
Pathogenic
-8.0
D;D;D;D;D
REVEL
Pathogenic
0.86
Sift
Uncertain
0.013
D;D;D;D;D
Sift4G
Uncertain
0.023
D;D;D;D;D
Polyphen
1.0
D;D;D;D;.
Vest4
0.89
MutPred
0.84
Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);
MVP
0.92
MPC
1.2
ClinPred
1.0
D
GERP RS
5.2
Varity_R
0.74
gMVP
0.93
Mutation Taster
=27/73
disease causing

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: rs147474549; hg19: chr21-44486404; API