rs775341386

chr2-165770196-G-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_004482.4(GALNT3):c.505C>T(p.Arg169Ter) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000682 in 1,613,972 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 (★★). Synonymous variant affecting the same amino acid position (i.e. R169R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: GALNT3 NM_004482.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 4.79

Genes affected

GALNT3 (HGNC:4125): (polypeptide N-acetylgalactosaminyltransferase 3) This gene encodes UDP-GalNAc transferase 3, a member of the GalNAc-transferases family. This family transfers an N-acetyl galactosamine to the hydroxyl group of a serine or threonine residue in the first step of O-linked oligosaccharide biosynthesis. Individual GalNAc-transferases have distinct activities and initiation of O-glycosylation is regulated by a repertoire of GalNAc-transferases. The protein encoded by this gene is highly homologous to other family members, however the enzymes have different substrate specificities. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-165770196-G-A is Pathogenic according to our data. Variant chr2-165770196-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 561015.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GALNT3	NM_004482.4	c.505C>T	p.Arg169Ter	stop_gained	2/11	ENST00000392701.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GALNT3	ENST00000392701.8	c.505C>T	p.Arg169Ter	stop_gained	2/11	1	NM_004482.4	P1
GALNT3	ENST00000412248.5	c.505C>T	p.Arg169Ter	stop_gained	3/8	5

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152122 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251310 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135832

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.0000462

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000616 AC: 9 AN: 1461850 Hom.: 0 Cov.: 32 AF XY: 0.00000688 AC XY: 5 AN XY: 727218

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.0000562

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152122 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74320

Gnomad4 AFR AF: 0.0000241

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: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Tumoral calcinosis, hyperphosphatemic, familial, 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Sep 01, 2017

This nonsense mutation is categorized as deleterious according to ACMG guidelines (PMID:18414213) and was found once in our laboratory homozygous in a 16-year-old female with hyperphosphatemic tumoral calcification -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jun 16, 2023

This sequence change creates a premature translational stop signal (p.Arg169*) in the GALNT3 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in GALNT3 are known to be pathogenic (PMID: 15133511, 20358599). For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 561015). This variant has not been reported in the literature in individuals affected with GALNT3-related conditions. This variant is present in population databases (rs775341386, gnomAD 0.004%). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.63
Cadd	Pathogenic	39
Dann	Uncertain	1.0
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.53
FATHMM_MKL	Pathogenic	0.98	D
MutationTaster	Benign	1.0	A
Vest4		0.85
GERP RS		4.9

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.17		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: rs775341386; hg19: chr2-166626706;