chr3-25719514-TA-T

Position:

• chr3-25719514-TA-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_018297.4(NGLY1):​c.1910del​(p.Leu637Ter) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: NGLY1 NM_018297.4 frameshift
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 5.97

Genes affected

NGLY1 (HGNC:17646): (N-glycanase 1) This gene encodes an enzyme that catalyzes hydrolysis of an N(4)-(acetyl-beta-D-glucosaminyl) asparagine residue to N-acetyl-beta-D-glucosaminylamine and a peptide containing an aspartate residue. The encoded enzyme may play a role in the proteasome-mediated degradation of misfolded glycoproteins. Multiple transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Feb 2009]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.028 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 3-25719514-TA-T is Pathogenic according to our data. Variant chr3-25719514-TA-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 221582.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NGLY1	NM_018297.4	c.1910del	p.Leu637Ter	frameshift_variant	12/12	ENST00000280700.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NGLY1	ENST00000280700.10	c.1910del	p.Leu637Ter	frameshift_variant	12/12	1	NM_018297.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Congenital disorder of deglycosylation Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Medical Biochemical Genetics, National Human Genome institute, NIH, National Institutes of Health

Jan 07, 2016

- -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Mar 21, 2019

A variant that is likely pathogenic has been identified in the NGLY1 gene. The L637X variant has been previously reported in a patient with a clinical diagnosis of NGLY1-CDDG who had a second variant on the opposite allele (Lam et al., 2017; Kong et al., 2017). The L637X variant is not observed in large population cohorts (Lek et al., 2016). L637X is predicted to cause loss of normal protein function through protein truncation as the last 18 amino acids are lost. Therefore, this variant is likely pathogenic; however, the possibility that it is benign cannot be excluded. -

Computational scores

Source: dbNSFP v4.3

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: rs1135401730; hg19: chr3-25761005;