chr12-57626856-C-G

Position:

• chr12-57626856-C-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001478.5(B4GALNT1):​c.1490G>C​(p.Gly497Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: B4GALNT1 NM_001478.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.862

Genes affected

B4GALNT1 (HGNC:4117): (beta-1,4-N-acetyl-galactosaminyltransferase 1) GM2 and GD2 gangliosides are sialic acid-containing glycosphingolipids. GalNAc-T is the enzyme involved in the biosynthesis of G(M2) and G(D2) glycosphingolipids. GalNAc-T catalyzes the transfer of GalNAc into G(M3) and G(D3) by a beta-1,4 linkage, resulting in the synthesis of G(M2) and G(D2), respectively. Three transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Feb 2013]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.048497796).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
B4GALNT1	NM_001478.5	c.1490G>C	p.Gly497Ala	missense_variant	11/11	ENST00000341156.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
B4GALNT1	ENST00000341156.9	c.1490G>C	p.Gly497Ala	missense_variant	11/11	1	NM_001478.5	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 13, 2021

The c.1490G>C (p.G497A) alteration is located in exon 11 (coding exon 10) of the B4GALNT1 gene. This alteration results from a G to C substitution at nucleotide position 1490, causing the glycine (G) at amino acid position 497 to be replaced by an alanine (A). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.066
BayesDel_addAF	Benign	-0.33	T
BayesDel_noAF	Benign	-0.71
CADD	Benign	1.5
DANN	Benign	0.63
DEOGEN2	Benign	0.21	T;.
Eigen	Benign	-1.4
Eigen_PC	Benign	-1.5
FATHMM_MKL	Benign	0.095	N
LIST_S2	Benign	0.59	T;T
M_CAP	Benign	0.0036	T
MetaRNN	Benign	0.048	T;T
MetaSVM	Benign	-0.94	T
MutationAssessor	Benign	0.29	N;.
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.30	T
PROVEAN	Benign	0.24	N;N
REVEL	Benign	0.0090
Sift	Benign	0.75	T;T
Sift4G	Benign	0.77	T;T
Polyphen		0.0070	B;.
Vest4		0.078
MutPred		0.24		Gain of catalytic residue at D495 (P = 0.0534);.;
MVP		0.15
MPC		0.89
ClinPred		0.028	T
GERP RS		-3.1
Varity_R		0.036
gMVP		0.42

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1884844519; hg19: chr12-58020639;