22-42619922-C-T

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM2PP5_Very_Strong

The NM_000398.7(CYB5R3):c.757G>A(p.Val253Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000629 in 1,605,364 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. V253V) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000063 ( 1 hom. )

Consequence

CYB5R3
NM_000398.7 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:10

Conservation

PhyloP100: 4.50

Publications

9 publications found

Variant links:

Genes affected

CYB5R3 (HGNC:2873): (cytochrome b5 reductase 3) This gene encodes cytochrome b5 reductase, which includes a membrane-bound form in somatic cells (anchored in the endoplasmic reticulum, mitochondrial and other membranes) and a soluble form in erythrocytes. The membrane-bound form exists mainly on the cytoplasmic side of the endoplasmic reticulum and functions in desaturation and elongation of fatty acids, in cholesterol biosynthesis, and in drug metabolism. The erythrocyte form is located in a soluble fraction of circulating erythrocytes and is involved in methemoglobin reduction. The membrane-bound form has both membrane-binding and catalytic domains, while the soluble form has only the catalytic domain. Alternate splicing results in multiple transcript variants. Mutations in this gene cause methemoglobinemias. [provided by RefSeq, Jan 2010]

CYB5R3 Gene-Disease associations (from GenCC):

methemoglobinemia
Inheritance: AR Classification: DEFINITIVE Submitted by: Illumina
methemoglobinemia due to deficiency of methemoglobin reductase
Inheritance: AR Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
hereditary methemoglobinemia
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

CYB5R3 links:

ENSG00000289517 (HGNC:):

ENSG00000289517 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 10 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 22-42619922-C-T is Pathogenic according to our data. Variant chr22-42619922-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 505719.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
CYB5R3	NM_000398.7 link	c.757G>A	p.Val253Met	missense_variant	Exon 9 of 9	ENST00000352397.10	NP_000389.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CYB5R3	ENST00000352397.10 link	c.757G>A	p.Val253Met	missense_variant	Exon 9 of 9	1	NM_000398.7	ENSP00000338461.6
ENSG00000289517	ENST00000617178.5 link	n.292G>A		non_coding_transcript_exon_variant	Exon 4 of 14	1		ENSP00000482500.2

Frequencies

GnomAD3 genomes

AF:

0.0000591

AC:

AN:

152190

Hom.:

Cov.:

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:

0.000132

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000103

AC:

AN:

232778

AF XY:

0.0000873

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000121

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000182

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000633

AC:

AN:

1453174

Hom.:

Cov.:

AF XY:

0.0000776

AC XY:

AN XY:

722066

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33324

American (AMR)

AF:

0.000137

AC:

AN:

43706

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25884

East Asian (EAS)

AF:

0.00

AC:

AN:

39356

South Asian (SAS)

AF:

0.0000236

AC:

AN:

84624

European-Finnish (FIN)

AF:

0.00

AC:

AN:

52454

Middle Eastern (MID)

AF:

0.000347

AC:

AN:

5760

European-Non Finnish (NFE)

AF:

0.0000713

AC:

AN:

1108030

Other (OTH)

AF:

0.0000500

AC:

AN:

60036

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.461

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.0000591

AC:

AN:

152190

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74340

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41442

American (AMR)

AF:

0.00

AC:

AN:

15282

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5196

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10626

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000132

AC:

AN:

68022

Other (OTH)

AF:

0.00

AC:

AN:

2090

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.519

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.000112

Hom.:

Bravo

AF:

0.0000718

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.0000990

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:10

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Deficiency of cytochrome-b5 reductase

Pathogenic:4

Jul 09, 2021

Fulgent Genetics, Fulgent Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Institute of Human Genetics, University Hospital of Duesseldorf

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:not provided

- -

Feb 25, 2023

Revvity Omics, Revvity

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

May 17, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: CYB5R3 c.757G>A (p.Val253Met) results in a conservative amino acid change located in the Oxidoreductase NAD-binding domain of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.0001 in 232778 control chromosomes. c.757G>A has been reported in the literature in multiple individuals affected with Deficiency Of Cytochrome-B5 Reductase. These data indicate that the variant is very likely to be associated with disease. Two patients who were homozygotes for the c.757G>A mutation showed almost no metHb reductase activity. ClinVar contains an entry for this variant (Variation ID: 505719). Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided

Pathogenic:4

Oct 16, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 253 of the CYB5R3 protein (p.Val253Met). This variant is present in population databases (rs144071404, gnomAD 0.01%). This missense change has been observed in individuals with methemoglobinemia (PMID: 11159544, 11295830, 12756024, 16310381, 21349748). It has also been observed to segregate with disease in related individuals. This variant is also known as V252M. ClinVar contains an entry for this variant (Variation ID: 505719). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on CYB5R3 protein function. Experimental studies have shown that this missense change affects CYB5R3 function (PMID: 16310381). For these reasons, this variant has been classified as Pathogenic. -

Jun 01, 2024

CeGaT Center for Human Genetics Tuebingen

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

CYB5R3: PM3:Strong, PP1:Strong, PM2, PS3:Supporting -

Mar 18, 2021

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Mar 30, 2022

GeneDx

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Published functional studies demonstrate a damaging effect: decreased catalytic efficiency and reduced protein stability (PMID: 16310381); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 11159544, 21349748, 34426522, 30609409, 11295830, 16310381, 12756024, 24266649) -

Hereditary methemoglobinemia

Pathogenic:1

Mar 30, 2020

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

proposed classification - variant undergoing re-assessment, contact laboratory -

Central core myopathy

Pathogenic:1

Dec 18, 2024

Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.78

BayesDel_addAF

Pathogenic

0.20

BayesDel_noAF

Pathogenic

0.27

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.58

.;D;.;.;.

Eigen

Pathogenic

0.73

Eigen_PC

Pathogenic

0.67

FATHMM_MKL

Uncertain

0.82

LIST_S2

Uncertain

0.87

D;D;.;.;D

M_CAP

Uncertain

0.26

MetaRNN

Uncertain

0.64

D;D;D;D;D

MetaSVM

Pathogenic

0.94

MutationAssessor

Pathogenic

3.1

.;M;.;.;.

PhyloP100

4.5

PrimateAI

Uncertain

0.68

PROVEAN

Uncertain

-2.6

D;D;D;D;D

REVEL

Pathogenic

0.85

Sift

Uncertain

0.017

D;D;D;D;D

Sift4G

Uncertain

0.058

T;T;T;T;T

Polyphen

0.99

.;D;.;.;.

Vest4

0.53

MVP

0.99

MPC

0.22

ClinPred

0.72

GERP RS

4.6

Varity_R

0.81

gMVP

0.65

Mutation Taster

=4/96

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over