21-43068529-A-T

Position:

chr21-43068529-A-T

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM1BP4_StrongBP6

The ENST00000398165.8(CBS):c.296T>A(p.Phe99Tyr) variant causes a missense change involving the alteration of a non-conserved nucleotide. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. F99L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00021 ( 0 hom., cov: 6)

Exomes 𝑓: 0.000035 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

CBS
ENST00000398165.8 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:2

Conservation

PhyloP100: 0.670

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -3 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 5 uncertain in ENST00000398165.8

BP4

Computational evidence support a benign effect (MetaRNN=0.019435287).

BP6

Variant 21-43068529-A-T is Benign according to our data. Variant chr21-43068529-A-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 405376.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=4}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CBS	NM_000071.3 linkuse as main transcript	c.296T>A	p.Phe99Tyr	missense_variant	4/17	ENST00000398165.8	NP_000062.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CBS	ENST00000398165.8 linkuse as main transcript	c.296T>A	p.Phe99Tyr	missense_variant	4/17	1	NM_000071.3	ENSP00000381231	P1	P35520-1

Frequencies

GnomAD3 genomes

AF:

0.00

AC:

AN:

38986

Hom.:

Cov.:

FAILED QC

Gnomad AFR

AF:

0.000984

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

GnomAD3 exomes

AF:

0.000115

AC:

AN:

251360

Hom.:

AF XY:

0.000125

AC XY:

AN XY:

135876

show subpopulations

Gnomad AFR exome

AF:

0.00160

Gnomad AMR exome

AF:

0.0000578

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:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

Data not reliable, filtered out with message: AS_VQSR

AF:

0.0000352

AC:

AN:

340968

Hom.:

Cov.:

AF XY:

0.0000327

AC XY:

AN XY:

183546

show subpopulations

Gnomad4 AFR exome

AF:

0.00123

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:

0.00000535

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Data not reliable, filtered out with message: AS_VQSR

AF:

0.000205

AC:

AN:

38986

Hom.:

Cov.:

AF XY:

0.000112

AC XY:

AN XY:

17918

show subpopulations

Gnomad4 AFR

AF:

0.000984

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

ESP6500AA

AF:

0.00182

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000123

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:1

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Sep 10, 2019	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Mayo Clinic Laboratories, Mayo Clinic	Dec 14, 2023	BP4 -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Aug 16, 2016

- -

Classic homocystinuria

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Jul 14, 2021

- -

HYPERHOMOCYSTEINEMIA, THROMBOTIC, CBS-RELATED

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 19, 2022

This sequence change replaces phenylalanine, which is neutral and non-polar, with tyrosine, which is neutral and polar, at codon 99 of the CBS protein (p.Phe99Tyr). This variant is present in population databases (rs112029370, gnomAD 0.2%). 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: 405376). 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. -

Familial thoracic aortic aneurysm and aortic dissection

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 20, 2021

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

0.074

BayesDel_addAF

Benign

-0.28

BayesDel_noAF

Benign

-0.18

CADD

Benign

DANN

Benign

0.80

DEOGEN2

Uncertain

0.64

D;D;D;D;.

Eigen

Benign

-1.3

Eigen_PC

Benign

-1.2

FATHMM_MKL

Uncertain

0.77

LIST_S2

Benign

0.83

.;.;.;T;T

M_CAP

Uncertain

0.15

MetaRNN

Benign

0.019

T;T;T;T;T

MetaSVM

Uncertain

0.28

MutationAssessor

Benign

0.35

N;N;N;N;.

MutationTaster

Benign

1.0

N;N;N;N;N;N;N;N;N;N;N;N

PrimateAI

Uncertain

0.52

PROVEAN

Benign

0.40

N;N;N;N;N

REVEL

Benign

0.24

Sift

Benign

1.0

T;T;T;T;T

Sift4G

Benign

1.0

T;T;T;T;T

Polyphen

0.0

B;B;B;B;.

Vest4

0.34

MVP

0.29

MPC

0.39

ClinPred

0.014

GERP RS

-3.7

Varity_R

0.12

gMVP

0.76

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over