22-42692934-G-A

Position:

chr22-42692934-G-A

Variant summary

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

The NM_017436.7(A4GALT):c.1018C>T(p.Arg340Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000087 in 1,609,630 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

A4GALT
NM_017436.7 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.93

Variant links:

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]

A4GALT links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

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 linkuse as main transcript	c.1018C>T	p.Arg340Cys	missense_variant	3/3	ENST00000642412.2	NP_059132.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
A4GALT	ENST00000642412.2 linkuse as main transcript	c.1018C>T	p.Arg340Cys	missense_variant	3/3		NM_017436.7	ENSP00000494127	P1

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152202

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

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

GnomAD3 exomes

AF:

0.00000807

AC:

AN:

247754

Hom.:

AF XY:

0.0000149

AC XY:

AN XY:

134462

show subpopulations

Gnomad AFR exome

AF:

0.0000618

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000887

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000549

AC:

AN:

1457428

Hom.:

Cov.:

AF XY:

0.00000827

AC XY:

AN XY:

725268

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000450

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152202

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74348

show subpopulations

Gnomad4 AFR

AF:

0.0000724

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000142

Hom.:

Bravo

AF:

0.0000340

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.000164

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 20, 2022

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Not Available"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Not Available"). This variant has not been reported in the literature in individuals affected with A4GALT-related conditions. This variant is present in population databases (rs771082385, gnomAD 0.004%). This sequence change replaces arginine with cysteine at codon 340 of the A4GALT protein (p.Arg340Cys). The arginine residue is moderately conserved and there is a large physicochemical difference between arginine and cysteine. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.16

BayesDel_addAF

Benign

-0.055

BayesDel_noAF

Benign

-0.13

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.40

T;T;T;T

Eigen

Uncertain

0.50

Eigen_PC

Uncertain

0.47

FATHMM_MKL

Benign

0.68

LIST_S2

Uncertain

0.95

.;.;D;.

M_CAP

Uncertain

0.20

MetaRNN

Uncertain

0.58

D;D;D;D

MetaSVM

Uncertain

-0.19

MutationAssessor

Uncertain

2.3

M;M;M;M

MutationTaster

Benign

1.0

N;N;N

PrimateAI

Benign

0.37

PROVEAN

Uncertain

-3.7

.;D;D;D

REVEL

Uncertain

0.45

Sift

Uncertain

0.0050

.;D;D;D

Sift4G

Uncertain

0.019

.;D;D;D

Polyphen

0.99

D;D;D;D

Vest4

0.45

MutPred

0.55

Loss of MoRF binding (P = 0.0288);Loss of MoRF binding (P = 0.0288);Loss of MoRF binding (P = 0.0288);Loss of MoRF binding (P = 0.0288);

MVP

0.98

MPC

1.0

ClinPred

0.96

GERP RS

5.3

Varity_R

0.35

gMVP

0.40

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over