22-42693169-C-T

Position:

• chr22-42693169-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_017436.7(A4GALT):​c.783G>A​(p.Trp261Ter) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Affects (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: A4GALT NM_017436.7 stop_gained
• Clinical Significance: Affects no assertion criteria provided O:1
• Conservation: PhyloP100: 3.78

Genes affected

A4GALT (HGNC:18149): (alpha 1,4-galactosyltransferase (P1PK blood group)) The protein encoded by this gene catalyzes the transfer of galactose to lactosylceramide to form globotriaosylceramide, which has been identified as the P(k) antigen of the P blood group system. This protein, a type II membrane protein found in the Golgi, is also required for the synthesis of the bacterial verotoxins receptor. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Dec 2015]

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.

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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
A4GALT	NM_017436.7	c.783G>A	p.Trp261Ter	stop_gained	3/3	ENST00000642412.2	NP_059132.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
A4GALT	ENST00000642412.2	c.783G>A	p.Trp261Ter	stop_gained	3/3		NM_017436.7	ENSP00000494127	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 66

GnomAD4 genome Cov.: 32

ClinVar

Significance: Affects

Submissions summary: Other:1

Revision: no assertion criteria provided

Submissions by phenotype

p phenotype Other:1

Affects, no assertion criteria provided

literature only

OMIM

Mar 29, 2002

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	40
DANN	Uncertain	1.0
Eigen	Pathogenic	0.82
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Uncertain	0.85	D
MutationTaster	Benign	1.0	A;A;A
Vest4		0.27
GERP RS		5.3

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

LitVar

Other links and lift over

dbSNP: rs74315454; hg19: chr22-43089175;