21-29561642-C-A

Variant names:

• chr21-29561642-C-A
• rs1389738147
• NM_001330994.2:c.2338G>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_001330994.2(GRIK1):​c.2338G>T​(p.Gly780*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,458,914 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: GRIK1 NM_001330994.2 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.87
• Publications: 0 publications found

Genes affected

GRIK1 (HGNC:4579): (glutamate ionotropic receptor kainate type subunit 1) 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 (CAG->CGG; Q->R) within the second transmembrane domain, which is thought to alter the properties of ion flow. Alternative splicing, resulting in transcript variants encoding different isoforms, has been noted for this gene. [provided by RefSeq, Jul 2008]

BACH1 (HGNC:935): (BTB domain and CNC homolog 1) This gene encodes a transcription factor that belongs to the cap'n'collar type of basic region leucine zipper factor family (CNC-bZip). The encoded protein contains broad complex, tramtrack, bric-a-brac/poxvirus and zinc finger (BTB/POZ) domains, which is atypical of CNC-bZip family members. These BTB/POZ domains facilitate protein-protein interactions and formation of homo- and/or hetero-oligomers. When this encoded protein forms a heterodimer with MafK, it functions as a repressor of Maf recognition element (MARE) and transcription is repressed. Multiple alternatively spliced transcript variants have been identified for this gene. [provided by RefSeq, May 2009]

ENSG00000296862 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001330994.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GRIK1	NM_001330994.2	MANE Select	c.2338G>T	p.Gly780*	stop_gained	Exon 15 of 18	NP_001317923.1	E7ENK3
	GRIK1	NM_001330993.2		c.2293G>T	p.Gly765*	stop_gained	Exon 14 of 17	NP_001317922.1	E7EPY9
	GRIK1	NM_001320616.2		c.2338G>T	p.Gly780*	stop_gained	Exon 15 of 17	NP_001307545.1	E9PD61

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GRIK1	ENST00000327783.9	TSL:5 MANE Select	c.2338G>T	p.Gly780*	stop_gained	Exon 15 of 18	ENSP00000327687.4	E7ENK3
	GRIK1	ENST00000399907.6	TSL:1	c.2338G>T	p.Gly780*	stop_gained	Exon 15 of 17	ENSP00000382791.1	P39086-1
	GRIK1	ENST00000389125.7	TSL:1	c.2293G>T	p.Gly765*	stop_gained	Exon 14 of 16	ENSP00000373777.3	P39086-2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1458914 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 725980

African (AFR) AF: 0.00 AC: 0 AN: 33424

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26114

East Asian (EAS) AF: 0.00 AC: 0 AN: 39684

South Asian (SAS) AF: 0.00 AC: 0 AN: 86192

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 9.01e-7 AC: 1 AN: 1109276

Other (OTH) AF: 0.00 AC: 0 AN: 60322

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	48
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Pathogenic	0.98	D
PhyloP100		7.9
Vest4		0.96
GERP RS		4.8
Mutation Taster		=0/200	disease causing (fs/PTC)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.21		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.21		Position offset: 6
DS_DL_spliceai		0.20		Position offset: -18

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1389738147; hg19: chr21-30933963;