chr2-165754931-C-T

Position:

• chr2-165754931-C-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1_Moderate PM2 PP5_Very_Strong

The NM_004482.4(GALNT3):​c.1524+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000089 in 1,460,770 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000089 (0 hom.)
• Consequence: GALNT3 NM_004482.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.91

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 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.068874866 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.4, offset of -37, new splice context is: ggtGTatgt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-165754931-C-T is Pathogenic according to our data. Variant chr2-165754931-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 7791.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GALNT3	NM_004482.4	c.1524+1G>A		splice_donor_variant, intron_variant		ENST00000392701.8	NP_004473.2
GALNT3	XM_005246449.2	c.1524+1G>A		splice_donor_variant, intron_variant			XP_005246506.1
GALNT3	XM_011510929.2	c.1524+1G>A		splice_donor_variant, intron_variant			XP_011509231.1
GALNT3	XM_017003770.2	c.1524+1G>A		splice_donor_variant, intron_variant			XP_016859259.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GALNT3	ENST00000392701.8	c.1524+1G>A		splice_donor_variant, intron_variant		1	NM_004482.4	ENSP00000376465.3
GALNT3	ENST00000409882.5	c.738+1G>A		splice_donor_variant, intron_variant		1		ENSP00000386955.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000890 AC: 13 AN: 1460770 Hom.: 0 Cov.: 31 AF XY: 0.00000963 AC XY: 7 AN XY: 726780

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: 0.0000116

Gnomad4 FIN exome AF: 0.0000187

Gnomad4 NFE exome AF: 0.00000990

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Tumoral calcinosis, hyperphosphatemic, familial, 1 Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	May 05, 2020	This variant was determined to be pathogenic according to ACMG Guidelines, 2015 [PMID:25741868]. -
Pathogenic, no assertion criteria provided	literature only	OMIM	Jan 01, 2005	- -
Pathogenic, criteria provided, single submitter	clinical testing	Center for Genomic Medicine, King Faisal Specialist Hospital and Research Center	Mar 26, 2024	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.44
CADD	Pathogenic	34
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Uncertain	0.97	D
GERP RS		5.5

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DL_spliceai		1.0		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs745655924; hg19: chr2-166611441;