chr1-46189049-C-T

Position:

• chr1-46189049-C-T

Variant summary

Our verdict is Benign. Variant got -11 ACMG points: 0P and 11B. BP4_Moderate BP6 BS1 BS2

The NM_017739.4(POMGNT1):​c.*221G>A variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00249 in 1,539,064 control chromosomes in the GnomAD database, including 28 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0035 (1 hom., cov: 32)
  • Exomes 𝑓: 0.0024 (27 hom.)
• Consequence: POMGNT1 NM_017739.4 3_prime_UTR
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2 B:1
• Conservation: PhyloP100: 1.93

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 Benign. Variant got -11 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.4).
• BP6: Variant 1-46189049-C-T is Benign according to our data. Variant chr1-46189049-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 876536.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=2}.
• BS1: Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.00349 (532/152336) while in subpopulation NFE AF= 0.00463 (315/68024). AF 95% confidence interval is 0.00421. There are 1 homozygotes in gnomad4. There are 275 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.
• BS2: High Homozygotes in GnomAdExome4 at 27 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POMGNT1	NM_017739.4	c.*221G>A		3_prime_UTR_variant	22/22	ENST00000371984.8	NP_060209.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POMGNT1	ENST00000371984.8	c.*221G>A		3_prime_UTR_variant	22/22	1	NM_017739.4	ENSP00000361052	P1

Frequencies

GnomAD3 genomes AF: 0.00349 AC: 532 AN: 152218 Hom.: 1 Cov.: 32

Gnomad AFR AF: 0.000169

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000523

Gnomad ASJ AF: 0.0141

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.0140

Gnomad MID AF: 0.00316

Gnomad NFE AF: 0.00463

Gnomad OTH AF: 0.00143

GnomAD4 exome AF: 0.00238 AC: 3307 AN: 1386728 Hom.: 27 Cov.: 30 AF XY: 0.00248 AC XY: 1693 AN XY: 682922

Gnomad4 AFR exome AF: 0.0000966

Gnomad4 AMR exome AF: 0.000410

Gnomad4 ASJ exome AF: 0.0135

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000135

Gnomad4 FIN exome AF: 0.0163

Gnomad4 NFE exome AF: 0.00195

Gnomad4 OTH exome AF: 0.00290

GnomAD4 genome AF: 0.00349 AC: 532 AN: 152336 Hom.: 1 Cov.: 32 AF XY: 0.00369 AC XY: 275 AN XY: 74490

Gnomad4 AFR AF: 0.000168

Gnomad4 AMR AF: 0.000522

Gnomad4 ASJ AF: 0.0141

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.0140

Gnomad4 NFE AF: 0.00463

Gnomad4 OTH AF: 0.00142

Alfa AF: 0.00752 Hom.: 1

Bravo AF: 0.00209

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:2 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2O Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Congenital Muscular Dystrophy, alpha-dystroglycan related Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Jul 17, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.40
CADD	Benign	15
DANN	Benign	0.91
BranchPoint Hunter		2.0

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: rs181362801; hg19: chr1-46654721;