22-42630965-G-C

Variant names:

• chr22-42630965-G-C
• rs1210302322
• NM_000398.7:c.250C>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_000398.7(CYB5R3):​c.250C>G​(p.Arg84Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,668 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R84Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: CYB5R3 NM_000398.7 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.47
• Publications: 3 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):

• methemoglobinemia

  Inheritance: AR Classification: DEFINITIVE Submitted by: Illumina
• methemoglobinemia due to deficiency of methemoglobin reductase

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, ClinGen, Labcorp Genetics (formerly Invitae)
• hereditary methemoglobinemia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CYB5R3	NM_000398.7	MANE Select	c.250C>G	p.Arg84Gly	missense	Exon 4 of 9	NP_000389.1	P00387-1
	CYB5R3	NM_001171660.2		c.349C>G	p.Arg117Gly	missense	Exon 4 of 9	NP_001165131.1	P00387-3
	CYB5R3	NM_001129819.2		c.181C>G	p.Arg61Gly	missense	Exon 4 of 9	NP_001123291.1	P00387-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CYB5R3	ENST00000352397.10	TSL:1 MANE Select	c.250C>G	p.Arg84Gly	missense	Exon 4 of 9	ENSP00000338461.6	P00387-1
	CYB5R3	ENST00000407332.6	TSL:1	c.268C>G	p.Arg90Gly	missense	Exon 4 of 9	ENSP00000384457.2	A0A8J8Z3C6
	CYB5R3	ENST00000470741.1	TSL:1	n.2384C>G		non_coding_transcript_exon	Exon 1 of 6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000399 AC: 1 AN: 250446 AF XY: 0.00000737

Gnomad AFR exome AF: 0.0000619

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461668 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727134

African (AFR) AF: 0.0000597 AC: 2 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44704

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26124

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86188

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53364

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1111952

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.35
BayesDel_addAF	Benign	-0.060	T
BayesDel_noAF	Benign	-0.14
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.43	T
Eigen	Benign	-0.40
Eigen_PC	Benign	-0.49
FATHMM_MKL	Benign	0.56	D
LIST_S2	Uncertain	0.96	D
M_CAP	Uncertain	0.091	D
MetaRNN	Uncertain	0.42	T
MetaSVM	Benign	-0.37	T
MutationAssessor	Uncertain	2.3	M
PhyloP100		2.5
PrimateAI	Uncertain	0.50	T
PROVEAN	Pathogenic	-5.1	D
REVEL	Uncertain	0.31
Sift	Benign	0.082	T
Sift4G	Benign	0.11	T
Polyphen		0.0030	B
Vest4		0.78
MutPred		0.41		Loss of stability (P = 0.0066)
MVP		0.87
MPC		0.13
ClinPred		0.79	D
GERP RS		0.31
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.71
gMVP		0.77
Mutation Taster		=73/27	polymorphism

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

Other links and lift over

dbSNP: rs1210302322; hg19: chr22-43026971;