22-42692981-G-A

Position:

chr22-42692981-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_017436.7(A4GALT):c.971C>T(p.Thr324Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000992 in 1,613,288 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

A4GALT
NM_017436.7 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 1.02

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 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.23494324).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
A4GALT	NM_017436.7 linkuse as main transcript	c.971C>T	p.Thr324Met	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.971C>T	p.Thr324Met	missense_variant	3/3		NM_017436.7	ENSP00000494127	P1

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152216

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000482

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000319

AC:

AN:

250444

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135662

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000145

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000177

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000890

AC:

AN:

1461072

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

726882

show subpopulations

Gnomad4 AFR exome

AF:

0.0000597

Gnomad4 AMR exome

AF:

0.000112

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:

0.00000180

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152216

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74372

show subpopulations

Gnomad4 AFR

AF:

0.0000482

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000868

Hom.:

Bravo

AF:

0.0000264

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 16, 2021

The c.971C>T (p.T324M) alteration is located in exon 3 (coding exon 1) of the A4GALT gene. This alteration results from a C to T substitution at nucleotide position 971, causing the threonine (T) at amino acid position 324 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 07, 2023

This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 324 of the A4GALT protein (p.Thr324Met). 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. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant¬†is likely to be tolerated. ClinVar contains an entry for this variant (Variation ID: 2375483). This variant has not been reported in the literature in individuals affected with A4GALT-related conditions. This variant is present in population databases (rs756022687, gnomAD 0.01%). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.092

BayesDel_addAF

Benign

-0.18

BayesDel_noAF

Benign

-0.24

CADD

Benign

DANN

Uncertain

0.99

DEOGEN2

Benign

0.18

T;T;T;T

Eigen

Benign

-0.16

Eigen_PC

Benign

-0.28

FATHMM_MKL

Benign

0.23

LIST_S2

Uncertain

0.89

.;.;D;.

M_CAP

Benign

0.063

MetaRNN

Benign

0.23

T;T;T;T

MetaSVM

Benign

-0.65

MutationAssessor

Uncertain

2.5

M;M;M;M

MutationTaster

Benign

1.0

N;N;N

PrimateAI

Benign

0.41

PROVEAN

Benign

-1.9

.;N;N;N

REVEL

Benign

0.18

Sift

Benign

0.097

.;T;T;T

Sift4G

Benign

0.078

.;T;T;T

Polyphen

0.96

D;D;D;D

Vest4

0.16, 0.16

MutPred

0.21

Gain of MoRF binding (P = 0.0818);Gain of MoRF binding (P = 0.0818);Gain of MoRF binding (P = 0.0818);Gain of MoRF binding (P = 0.0818);

MVP

0.86

MPC

0.49

ClinPred

0.11

GERP RS

1.8

Varity_R

0.068

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