rs368334961

chr12-57629105-G-Achr12-57629105-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001478.5(B4GALNT1):c.754C>T(p.Arg252Cys) variant causes a missense change. The variant allele was found at a frequency of 0.000095 in 1,599,314 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R252S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000039 (0 hom., cov: 33)
  • Exomes 𝑓: 0.00010 (0 hom.)
• Consequence: B4GALNT1 NM_001478.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.84

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 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=0.25291803).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
B4GALNT1	NM_001478.5	c.754C>T	p.Arg252Cys	missense_variant	7/11	ENST00000341156.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
B4GALNT1	ENST00000341156.9	c.754C>T	p.Arg252Cys	missense_variant	7/11	1	NM_001478.5	P1

Frequencies

GnomAD3 genomes AF: 0.0000394 AC: 6 AN: 152170 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

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: 0.0000882

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000446 AC: 11 AN: 246612 Hom.: 0 AF XY: 0.0000300 AC XY: 4 AN XY: 133188

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000592

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: 0.0000806

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000101 AC: 146 AN: 1447144 Hom.: 0 Cov.: 32 AF XY: 0.0000962 AC XY: 69 AN XY: 717088

Gnomad4 AFR exome AF: 0.0000301

Gnomad4 AMR exome AF: 0.0000456

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000117

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000127

Gnomad4 OTH exome AF: 0.0000335

GnomAD4 genome AF: 0.0000394 AC: 6 AN: 152170 Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2 AN XY: 74328

Gnomad4 AFR AF: 0.00

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: 0.0000882

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000169 Hom.: 0

Bravo AF: 0.0000642

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.000259 AC: 1

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.0000412 AC: 5

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Spastic paraplegia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Sep 27, 2022

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 252 of the B4GALNT1 protein (p.Arg252Cys). This variant is present in population databases (rs368334961, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with B4GALNT1-related conditions. ClinVar contains an entry for this variant (Variation ID: 458225). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt B4GALNT1 protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.16
BayesDel_addAF	Benign	-0.35	T
BayesDel_noAF	Benign	-0.40
Cadd	Pathogenic	30
Dann	Pathogenic	1.0
DEOGEN2	Uncertain	0.72	D;.
Eigen	Uncertain	0.37
Eigen_PC	Uncertain	0.39
FATHMM_MKL	Uncertain	0.87	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Benign	0.0082	T
MetaRNN	Benign	0.25	T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Uncertain	2.2	M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.54	T
PROVEAN	Uncertain	-2.6	D;N
REVEL	Benign	0.075
Sift	Benign	0.041	D;D
Sift4G	Uncertain	0.040	D;D
Polyphen		1.0	D;.
Vest4		0.39
MVP		0.38
MPC		0.70
ClinPred		0.34	T
GERP RS		4.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.26
gMVP		0.64

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: rs368334961; hg19: chr12-58022888;