rs61743717

chr22-42627642-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_000398.7(CYB5R3):c.510G>T(p.Arg170Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,872 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: CYB5R3 NM_000398.7 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.502

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM1: In a chain NADH-cytochrome b5 reductase 3 (size 299) in uniprot entity NB5R3_HUMAN there are 70 pathogenic changes around while only 8 benign (90%) in NM_000398.7
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.26021177).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CYB5R3	NM_000398.7	c.510G>T	p.Arg170Ser	missense_variant	6/9	ENST00000352397.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CYB5R3	ENST00000352397.10	c.510G>T	p.Arg170Ser	missense_variant	6/9	1	NM_000398.7	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461872 Hom.: 0 Cov.: 31 AF XY: 0.00000550 AC XY: 4 AN XY: 727242

Gnomad4 AFR exome AF: 0.00

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: 0.00000540

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.52
BayesDel_addAF	Uncertain	0.054	T
BayesDel_noAF	Benign	-0.16
Cadd	Benign	21
Dann	Benign	0.90
Eigen	Benign	-0.41
Eigen_PC	Benign	-0.36
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Benign	0.47	T;T;.;.;T;T
M_CAP	Benign	0.055	D
MetaRNN	Benign	0.24	T;T;T;T;T;T
MetaSVM	Benign	-0.48	T
MutationTaster	Benign	1.0	N;N;N;N;N;N
PrimateAI	Benign	0.32	T
PROVEAN	Uncertain	-2.7	D;D;D;D;D;D
REVEL	Benign	0.22
Sift	Benign	0.080	T;T;T;T;T;D
Sift4G	Benign	0.13	T;T;T;T;T;.
Polyphen		0.0020	.;B;.;.;.;.
Vest4		0.41
MutPred		0.41		.;Loss of MoRF binding (P = 0.0068);.;.;.;.;
MVP		0.87
MPC		0.043
ClinPred		0.68	D
GERP RS		2.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.35
gMVP		0.48

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

Other links and lift over

dbSNP: rs61743717; hg19: chr22-43023648;