rs753030030

Positions:

• chr1-46192180-C-A
• chr1-46192180-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_017739.4(POMGNT1):​c.1457G>T​(p.Arg486Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,878 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R486G) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: POMGNT1 NM_017739.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.72

Genes affected

POMGNT1 (HGNC:19139): (protein O-linked mannose N-acetylglucosaminyltransferase 1 (beta 1,2-)) This gene encodes a type II transmembrane protein that resides in the Golgi apparatus. It participates in O-mannosyl glycosylation and is specific for alpha linked terminal mannose. Mutations in this gene may be associated with muscle-eye-brain disease and several congenital muscular dystrophies. Alternatively spliced transcript variants that encode different protein isoforms have been described. [provided by RefSeq, Feb 2014]

TSPAN1 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_017739.4
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POMGNT1	NM_017739.4	c.1457G>T	p.Arg486Leu	missense_variant	17/22	ENST00000371984.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POMGNT1	ENST00000371984.8	c.1457G>T	p.Arg486Leu	missense_variant	17/22	1	NM_017739.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461878 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727240

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

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Muscular dystrophy-dystroglycanopathy (congenital with intellectual disability), type B3;C3150417:Autosomal recessive limb-girdle muscular dystrophy type 2O Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 01, 2022

This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 486 of the POMGNT1 protein (p.Arg486Leu). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with POMGNT1-related conditions. ClinVar contains an entry for this variant (Variation ID: 291115). 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 POMGNT1 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Sep 02, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Uncertain	0.074	D
BayesDel_noAF	Benign	-0.13
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.89	D;.
Eigen	Uncertain	0.36
Eigen_PC	Uncertain	0.44
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Uncertain	0.97	D;D
M_CAP	Uncertain	0.16	D
MetaRNN	Uncertain	0.56	D;D
MetaSVM	Uncertain	-0.16	T
MutationAssessor	Benign	1.8	L;L
MutationTaster	Benign	0.99	D;D;D;D;D
PrimateAI	Uncertain	0.55	T
PROVEAN	Pathogenic	-4.5	D;D
REVEL	Uncertain	0.47
Sift	Uncertain	0.0040	D;D
Sift4G	Uncertain	0.0070	D;D
Polyphen		0.60	P;.
Vest4		0.58
MutPred		0.63		Loss of disorder (P = 0.0292);Loss of disorder (P = 0.0292);
MVP		0.84
MPC		0.66
ClinPred		0.96	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.36
gMVP		0.71

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs753030030; hg19: chr1-46657852;