22-42619910-TCTC-T
Variant names: 
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
NM_000398.7 conservative_inframe_deletion
Scores
 Not classified 
Clinical Significance
Conservation
 PhyloP100:  7.93  
Publications
2 publications found 
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):
- methemoglobinemiaInheritance: AR Classification: DEFINITIVE Submitted by: Illumina
 - methemoglobinemia due to deficiency of methemoglobin reductaseInheritance: AR Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
 - hereditary methemoglobinemiaInheritance: 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. 
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt | 
|---|---|---|---|---|---|---|---|---|---|---|
| CYB5R3 | ENST00000352397.10  | c.766_768delGAG | p.Glu256del | conservative_inframe_deletion | Exon 9 of 9 | 1 | NM_000398.7 | ENSP00000338461.6 | ||
| ENSG00000289517 | ENST00000617178.5  | n.301_303delGAG | non_coding_transcript_exon_variant | Exon 4 of 14 | 1 | ENSP00000482500.2 | 
Frequencies
GnomAD3 genomes   AF:  0.0000197  AC: 3AN: 152018Hom.:  0  Cov.: 33 show subpopulations 
GnomAD3 genomes 
 AF: 
AC: 
3
AN: 
152018
Hom.: 
Cov.: 
33
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GnomAD2 exomes  AF:  0.0000169  AC: 4AN: 236696 AF XY:  0.0000312   show subpopulations 
GnomAD2 exomes 
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AC: 
4
AN: 
236696
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GnomAD4 exome  AF:  0.0000158  AC: 23AN: 1455246Hom.:  0   AF XY:  0.0000166  AC XY: 12AN XY: 723282 show subpopulations 
GnomAD4 exome 
 AF: 
AC: 
23
AN: 
1455246
Hom.: 
 AF XY: 
AC XY: 
12
AN XY: 
723282
show subpopulations 
African (AFR) 
 AF: 
AC: 
0
AN: 
33358
American (AMR) 
 AF: 
AC: 
0
AN: 
43996
Ashkenazi Jewish (ASJ) 
 AF: 
AC: 
0
AN: 
25930
East Asian (EAS) 
 AF: 
AC: 
0
AN: 
39458
South Asian (SAS) 
 AF: 
AC: 
0
AN: 
84924
European-Finnish (FIN) 
 AF: 
AC: 
0
AN: 
52534
Middle Eastern (MID) 
 AF: 
AC: 
0
AN: 
5762
European-Non Finnish (NFE) 
 AF: 
AC: 
21
AN: 
1109140
Other (OTH) 
 AF: 
AC: 
2
AN: 
60144
 Allele Balance Distribution 
 Red line indicates average allele balance 
 Average allele balance: 0.451 
Heterozygous variant carriers
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Allele balance
Age Distribution
Exome Het
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Age
GnomAD4 genome   AF:  0.0000197  AC: 3AN: 152018Hom.:  0  Cov.: 33 AF XY:  0.0000404  AC XY: 3AN XY: 74244 show subpopulations 
GnomAD4 genome 
 AF: 
AC: 
3
AN: 
152018
Hom.: 
Cov.: 
33
 AF XY: 
AC XY: 
3
AN XY: 
74244
show subpopulations 
African (AFR) 
 AF: 
AC: 
0
AN: 
41372
American (AMR) 
 AF: 
AC: 
0
AN: 
15260
Ashkenazi Jewish (ASJ) 
 AF: 
AC: 
0
AN: 
3470
East Asian (EAS) 
 AF: 
AC: 
0
AN: 
5192
South Asian (SAS) 
 AF: 
AC: 
0
AN: 
4828
European-Finnish (FIN) 
 AF: 
AC: 
0
AN: 
10616
Middle Eastern (MID) 
 AF: 
AC: 
0
AN: 
316
European-Non Finnish (NFE) 
 AF: 
AC: 
3
AN: 
67964
Other (OTH) 
 AF: 
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 
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 0.95 
Allele balance
Age Distribution
Genome Het
Variant carriers
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Age
Alfa 
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Bravo 
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ClinVar
Significance: Pathogenic 
Submissions summary: Pathogenic:1 
Revision: no assertion criteria provided
LINK: link 
Submissions by phenotype
METHEMOGLOBINEMIA, TYPE I    Pathogenic:1 
May 01, 2008
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only
- -
Computational scores
Source: 
Name
Calibrated prediction
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Prediction
 PhyloP100 
Splicing
Name
Calibrated prediction
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Prediction
 SpliceAI score (max) 
Details are displayed if max score is > 0.2
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at 
Publications
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