X-123464905-TG-CC

Variant names:

• chrX-123464905-TG-CC
• NM_000828.5:c.2117_2118delTGinsCC
• GRIA3 p.Met706Thr

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PS1 PP2 PP3

The NM_007325.5(GRIA3):​c.2117_2118delTGinsCC​(p.Met706Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M706V) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 23)
• Consequence: GRIA3 NM_007325.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 10.0
• Publications: 0 publications found

Genes affected

GRIA3 (HGNC:4573): (glutamate ionotropic receptor AMPA type subunit 3) Glutamate receptors are the predominant excitatory neurotransmitter receptors in the mammalian brain and are activated in a variety of normal neurophysiologic processes. These receptors are heteromeric protein complexes composed of multiple subunits, arranged to form ligand-gated ion channels. The classification of glutamate receptors is based on their activation by different pharmacologic agonists. The subunit encoded by this gene belongs to a family of AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate)-sensitive glutamate receptors, and is subject to RNA editing (AGA->GGA; R->G). Alternative splicing at this locus results in different isoforms, which may vary in their signal transduction properties. [provided by RefSeq, Jul 2008]

GRIA3 Gene-Disease associations (from GenCC):

• syndromic X-linked intellectual disability 94

  Inheritance: XL Classification: DEFINITIVE, STRONG, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• X-linked complex neurodevelopmental disorder

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen
• X-linked intellectual disability due to GRIA3 anomalies

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000307341 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PS1: Transcript NM_007325.5 (GRIA3) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 22 curated pathogenic missense variants (we use a threshold of 10). The gene has 7 curated benign missense variants. Trascript score misZ: NaN (below the threshold of 3.09). GenCC associations: The gene is linked to X-linked complex neurodevelopmental disorder, syndromic X-linked intellectual disability 94, X-linked intellectual disability due to GRIA3 anomalies.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_007325.5. 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
	GRIA3	NM_000828.5	MANE Plus Clinical	c.2117_2118delTGinsCC	p.Met706Thr	missense	N/A	NP_000819.4	P42263-1
	GRIA3	NM_007325.5	MANE Select	c.2117_2118delTGinsCC	p.Met706Thr	missense	N/A	NP_015564.5

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GRIA3	ENST00000620443.2	TSL:1 MANE Select	c.2117_2118delTGinsCC	p.Met706Thr	missense	N/A	ENSP00000478489.1	P42263-2
	GRIA3	ENST00000622768.5	TSL:5 MANE Plus Clinical	c.2117_2118delTGinsCC	p.Met706Thr	missense	N/A	ENSP00000481554.1	P42263-1
	GRIA3	ENST00000620581.4	TSL:1	n.2117_2118delTGinsCC		non_coding_transcript_exon	Exon 13 of 17	ENSP00000481875.1	A0A087WYJ6

Frequencies

GnomAD3 genomes Cov.: 23

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 23

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		10

Splicing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chrX-122598756;