12-57626833-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PM5 PP3 PP5_Moderate

The NM_001478.5(B4GALNT1):c.1513C>T(p.Arg505Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R505H) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: B4GALNT1 NM_001478.5 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.66

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_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr12-57626832-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 1074269.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.807
• PP5: Variant 12-57626833-G-A is Pathogenic according to our data. Variant chr12-57626833-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 989144.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
B4GALNT1	NM_001478.5	c.1513C>T	p.Arg505Cys	missense_variant	11/11	ENST00000341156.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
B4GALNT1	ENST00000341156.9	c.1513C>T	p.Arg505Cys	missense_variant	11/11	1	NM_001478.5	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461888 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727246

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary spastic paraplegia 26 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Paris Brain Institute, Inserm - ICM

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
BayesDel_addAF	Pathogenic	0.30	D
BayesDel_noAF	Pathogenic	0.19
Cadd	Pathogenic	33
Dann	Pathogenic	1.0
DEOGEN2	Pathogenic	0.87	D;.
Eigen	Pathogenic	0.72
Eigen_PC	Uncertain	0.63
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.93	D;D
M_CAP	Uncertain	0.24	D
MetaRNN	Pathogenic	0.81	D;D
MetaSVM	Benign	-0.52	T
MutationAssessor	Pathogenic	3.1	M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.61	T
PROVEAN	Pathogenic	-6.3	D;D
REVEL	Uncertain	0.63
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.72
MutPred		0.59		Gain of catalytic residue at R503 (P = 0.0116);.;
MVP		0.68
MPC		2.2
ClinPred		1.0	D
GERP RS		4.6
Varity_R		0.68
gMVP		0.95

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs1884842111; hg19: chr12-58020616;