12-13866109-TG-TGG

Variant names:

• chr12-13866109-T-TG
• rs398122823
• NM_000834.5:c.99dupC

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1 PP5_Very_Strong

The NM_000834.5(GRIN2B):​c.99dupC​(p.Ser34GlnfsTer25) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000547 in 1,461,546 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: GRIN2B NM_000834.5 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 0.977

Genes affected

GRIN2B (HGNC:4586): (glutamate ionotropic receptor NMDA type subunit 2B) This gene encodes a member of the N-methyl-D-aspartate (NMDA) receptor family within the ionotropic glutamate receptor superfamily. The encoded protein is a subunit of the NMDA receptor ion channel which acts as an agonist binding site for glutamate. The NMDA receptors mediate a slow calcium-permeable component of excitatory synaptic transmission in the central nervous system. The NMDA receptors are heterotetramers of seven genetically encoded, differentially expressed subunits including NR1 (GRIN1), NR2 (GRIN2A, GRIN2B, GRIN2C, or GRIN2D) and NR3 (GRIN3A or GRIN3B). The early expression of this gene in development suggests a role in brain development, circuit formation, synaptic plasticity, and cellular migration and differentiation. Naturally occurring mutations within this gene are associated with neurodevelopmental disorders including autism spectrum disorder, attention deficit hyperactivity disorder, epilepsy, and schizophrenia. [provided by RefSeq, Aug 2017]

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 107 pathogenic variants in the truncated region.
• PP5: Variant 12-13866109-T-TG is Pathogenic according to our data. Variant chr12-13866109-T-TG is described in ClinVar as [Likely_pathogenic]. Clinvar id is 430527.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GRIN2B	NM_000834.5	c.99dupC	p.Ser34GlnfsTer25	frameshift_variant	Exon 3 of 14	ENST00000609686.4	NP_000825.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GRIN2B	ENST00000609686.4	c.99dupC	p.Ser34GlnfsTer25	frameshift_variant	Exon 3 of 14	1	NM_000834.5	ENSP00000477455.1
GRIN2B	ENST00000630791.2	c.99dupC	p.Ser34GlnfsTer25	frameshift_variant	Exon 4 of 8	5		ENSP00000486677.3
GRIN2B	ENST00000627535.2	c.99dupC	p.Ser34GlnfsTer2	frameshift_variant	Exon 3 of 3	5		ENSP00000486411.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461546 Hom.: 0 Cov.: 34 AF XY: 0.00000963 AC XY: 7 AN XY: 727062

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: 0.000132

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.000153 Hom.: 0

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Intellectual disability, autosomal dominant 6 Pathogenic:4

May 21, 2020

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.1.1, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss-of-function is a known mechanism of disease for this gene. (N) 0107 - This gene is known to be associated with autosomal dominant disease. (N) 0201 - Variant is predicted to cause nonsense-mediated decay (NMD) and loss of protein (exon 2 of 13). (P) 0251 - Variant is heterozygous. (N) 0302 - Variant is present in gnomAD <0.001 for a dominant condition (1 Heterozygote). (P) 0401 - Variant is located in a gene associated with a severe early-onset dominant condition that is intolerant to loss-of-function variants. (P) 0702 - Comparable variants have strong previous evidence for pathogenicity (ClinVar). (P) 0802 - Moderate previous evidence of pathogenicity in unrelated individuals (ClinVar, O'Roak, BJ. (2012)). (P) 0905 - No segregation evidence has been identified for this variant. (N) 1007 - No published functional evidence has been identified for this variant. (N) 1208 - Inheritance information for this variant is not currently available. (N) -

Apr 04, 2017

Institute of Human Genetics, University of Leipzig Medical Center

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was identified as de novo (maternity and paternity confirmed). -

Dec 21, 2012

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Jun 01, 2022

Solve-RD Consortium

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: provider interpretation

Variant confirmed as disease-causing by referring clinical team -

not provided Pathogenic:1

Apr 25, 2017

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.99dupC variant in the GRIN2B gene has been reported previously as a de novo change in an individual with autism (O'Roak et al., 2012). The duplication causes a frameshift starting with codon Serine 34, changes this amino acid to a Glutamine residue and creates a premature Stop codon at position 25 of the new reading frame, denoted p.Ser34GlnfsX25. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. Therefore, this variant is likely pathogenic; however, the possibility that it is benign cannot be excluded. -

Intellectual disability Pathogenic:1

Sep 10, 2020

Diagnostic Laboratory, Strasbourg University Hospital

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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: rs398122823; hg19: chr12-14019043;