NM_021956.5:c.2226C>T

Variant names:

• chr6-102035481-C-T
• rs3213607
• NM_021956.5:c.2226C>T

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_Strong BP7 BS1

The NM_021956.5(GRIK2):​c.2226C>T​(p.Ile742Ile) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000485 in 1,608,960 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. I742I) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000046 (0 hom., cov: 31)
  • Exomes 𝑓: 0.000049 (0 hom.)
• Consequence: GRIK2 NM_021956.5 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.309
• Publications: 19 publications found

Genes affected

GRIK2 (HGNC:4580): (glutamate ionotropic receptor kainate type subunit 2) Glutamate receptors are the predominant excitatory neurotransmitter receptors in the mammalian brain and are activated in a variety of normal neurophysiologic processes. This gene product belongs to the kainate family of glutamate receptors, which are composed of four subunits and function as ligand-activated ion channels. The subunit encoded by this gene is subject to RNA editing at multiple sites within the first and second transmembrane domains, which is thought to alter the structure and function of the receptor complex. Alternatively spliced transcript variants encoding different isoforms have also been described for this gene. Mutations in this gene have been associated with autosomal recessive cognitive disability. [provided by RefSeq, Jul 2008]

GRIK2 Gene-Disease associations (from GenCC):

• complex neurodevelopmental disorder

  Inheritance: AR, AD Classification: DEFINITIVE, MODERATE Submitted by: ClinGen
• intellectual disability, autosomal recessive 6

  Inheritance: AR Classification: DEFINITIVE, STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• neurodevelopmental disorder with impaired language and ataxia and with or without seizures

  Inheritance: AD Classification: STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• autosomal recessive non-syndromic intellectual disability

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Benign. The variant received -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.57).
• BP7: Synonymous conserved (PhyloP=-0.309 with no splicing effect.
• BS1: Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.0000463 (7/151126) while in subpopulation NFE AF = 0.000104 (7/67558). AF 95% confidence interval is 0.000048. There are 0 homozygotes in GnomAd4. There are 4 alleles in the male GnomAd4 subpopulation. Median coverage is 31. This position passed quality control check.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_021956.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GRIK2	NM_021956.5	MANE Select	c.2226C>T	p.Ile742Ile	synonymous	Exon 15 of 17	NP_068775.1
	GRIK2	NM_001166247.1		c.2226C>T	p.Ile742Ile	synonymous	Exon 14 of 17	NP_001159719.1
	GRIK2	NM_175768.3		c.2226C>T	p.Ile742Ile	synonymous	Exon 14 of 17	NP_786944.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GRIK2	ENST00000369134.9	TSL:5 MANE Select	c.2226C>T	p.Ile742Ile	synonymous	Exon 15 of 17	ENSP00000358130.6
	GRIK2	ENST00000421544.6	TSL:1	c.2226C>T	p.Ile742Ile	synonymous	Exon 17 of 19	ENSP00000397026.1
	GRIK2	ENST00000369138.5	TSL:1	c.2226C>T	p.Ile742Ile	synonymous	Exon 14 of 17	ENSP00000358134.1

Frequencies

GnomAD3 genomes AF: 0.0000463 AC: 7 AN: 151126 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000104

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000199 AC: 5 AN: 250652 AF XY: 0.0000221

Gnomad AFR exome AF: 0.0000620

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000265

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000487 AC: 71 AN: 1457834 Hom.: 0 Cov.: 29 AF XY: 0.0000469 AC XY: 34 AN XY: 725428

African (AFR) AF: 0.00 AC: 0 AN: 33224

American (AMR) AF: 0.00 AC: 0 AN: 44584

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26000

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39650

South Asian (SAS) AF: 0.0000348 AC: 3 AN: 86146

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53410

Middle Eastern (MID) AF: 0.000174 AC: 1 AN: 5738

European-Non Finnish (NFE) AF: 0.0000586 AC: 65 AN: 1108922

Other (OTH) AF: 0.0000166 AC: 1 AN: 60160

GnomAD4 genome AF: 0.0000463 AC: 7 AN: 151126 Hom.: 0 Cov.: 31 AF XY: 0.0000542 AC XY: 4 AN XY: 73738

African (AFR) AF: 0.00 AC: 0 AN: 41240

American (AMR) AF: 0.00 AC: 0 AN: 15078

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3436

East Asian (EAS) AF: 0.00 AC: 0 AN: 5106

South Asian (SAS) AF: 0.00 AC: 0 AN: 4820

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10584

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.000104 AC: 7 AN: 67558

Other (OTH) AF: 0.00 AC: 0 AN: 2076

Alfa AF: 0.00 Hom.: 554

EpiCase AF: 0.00

EpiControl AF: 0.0000594

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.57
CADD	Benign	5.6
DANN	Benign	0.72
PhyloP100		-0.31

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

Other links and lift over

dbSNP: rs3213607; hg19: chr6-102483356; COSMIC: COSV59732667;