NM_000398.7:c.766_768delGAG

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2PM4_SupportingPP5_Moderate

The NM_000398.7(CYB5R3):​c.766_768delGAG​(p.Glu256del) variant causes a conservative inframe deletion change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000162 in 1,607,264 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

CYB5R3
NM_000398.7 conservative_inframe_deletion

Scores

Not classified

Clinical Significance

Likely pathogenic criteria provided, single submitter P:2

Conservation

PhyloP100: 7.93

Publications

2 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM4
Nonframeshift variant in NON repetitive region in NM_000398.7. Strenght limited to Supporting due to length of the change: 1aa.
PP5
Variant 22-42619910-TCTC-T is Pathogenic according to our data. Variant chr22-42619910-TCTC-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 251.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000398.7. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CYB5R3
NM_000398.7
MANE Select
c.766_768delGAGp.Glu256del
conservative_inframe_deletion
Exon 9 of 9NP_000389.1
CYB5R3
NM_001171660.2
c.865_867delGAGp.Glu289del
conservative_inframe_deletion
Exon 9 of 9NP_001165131.1
CYB5R3
NM_001129819.2
c.697_699delGAGp.Glu233del
conservative_inframe_deletion
Exon 9 of 9NP_001123291.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
CYB5R3
ENST00000352397.10
TSL:1 MANE Select
c.766_768delGAGp.Glu256del
conservative_inframe_deletion
Exon 9 of 9ENSP00000338461.6
CYB5R3
ENST00000407332.6
TSL:1
c.784_786delGAGp.Glu262del
conservative_inframe_deletion
Exon 9 of 9ENSP00000384457.2
CYB5R3
ENST00000470741.1
TSL:1
n.2900_2902delGAG
non_coding_transcript_exon
Exon 6 of 6

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152018
Hom.:
0
Cov.:
33
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000169
AC:
4
AN:
236696
AF XY:
0.0000312
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:
0.0000375
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000158
AC:
23
AN:
1455246
Hom.:
0
AF XY:
0.0000166
AC XY:
12
AN XY:
723282
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33358
American (AMR)
AF:
0.00
AC:
0
AN:
43996
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25930
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39458
South Asian (SAS)
AF:
0.00
AC:
0
AN:
84924
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52534
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
0.0000189
AC:
21
AN:
1109140
Other (OTH)
AF:
0.0000333
AC:
2
AN:
60144
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.451
Heterozygous variant carriers
0
1
3
4
6
7
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
AF:
0.0000197
AC:
3
AN:
152018
Hom.:
0
Cov.:
33
AF XY:
0.0000404
AC XY:
3
AN XY:
74244
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41372
American (AMR)
AF:
0.00
AC:
0
AN:
15260
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
67964
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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
Bravo
AF:
0.0000227

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:2
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Deficiency of cytochrome-b5 reductase Pathogenic:1
Apr 16, 2024
Revvity Omics, Revvity
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

METHEMOGLOBINEMIA, TYPE I Pathogenic:1
May 01, 2008
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
PhyloP100
7.9
Mutation Taster
=30/70
disease causing (ClinVar)

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: rs121965017; hg19: chr22-43015916; API