NM_006772.3:c.1387-2delA

Variant names:

• chr6-33438416-CA-C
• rs1760914246
• NM_006772.3:c.1387-2delA

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_006772.3(SYNGAP1):​c.1387-2delA variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SYNGAP1 NM_006772.3 splice_acceptor, intron
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.32
• Publications: 0 publications found

Genes affected

SYNGAP1 (HGNC:11497): (synaptic Ras GTPase activating protein 1) This gene encodes a Ras GTPase activating protein that is a member of the N-methyl-D-aspartate receptor complex. The N-terminal domain of the protein contains a Ras-GAP domain, a pleckstrin homology domain, and a C2 domain that may be involved in binding of calcium and phospholipids. The C-terminal domain consists of a ten histidine repeat region, serine and tyrosine phosphorylation sites, and a T/SXV motif required for postsynaptic scaffold protein interaction. The encoded protein negatively regulates Ras, Rap and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor trafficking to the postsynaptic membrane to regulate synaptic plasticity and neuronal homeostasis. Allelic variants of this gene are associated with intellectual disability and autism spectrum disorder. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2016]

MIR5004 (HGNC:43532): (microRNA 5004) microRNAs (miRNAs) are short (20-24 nt) non-coding RNAs that are involved in post-transcriptional regulation of gene expression in multicellular organisms by affecting both the stability and translation of mRNAs. miRNAs are transcribed by RNA polymerase II as part of capped and polyadenylated primary transcripts (pri-miRNAs) that can be either protein-coding or non-coding. The primary transcript is cleaved by the Drosha ribonuclease III enzyme to produce an approximately 70-nt stem-loop precursor miRNA (pre-miRNA), which is further cleaved by the cytoplasmic Dicer ribonuclease to generate the mature miRNA and antisense miRNA star (miRNA*) products. The mature miRNA is incorporated into a RNA-induced silencing complex (RISC), which recognizes target mRNAs through imperfect base pairing with the miRNA and most commonly results in translational inhibition or destabilization of the target mRNA. The RefSeq represents the predicted microRNA stem-loop. [provided by RefSeq, Sep 2009]

SYNGAP1-AS1 (HGNC:53831): (SYNGAP1 antisense RNA 1)

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 6.4, offset of 13, new splice context is: ggcctcggacttcctttcAGaca. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 6-33438416-CA-C is Pathogenic according to our data. Variant chr6-33438416-CA-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 987236.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006772.3. 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
	SYNGAP1	NM_006772.3	MANE Select	c.1387-2delA		splice_acceptor intron	N/A	NP_006763.2	A0A1U9X8L0
	SYNGAP1	NM_001130066.2		c.1387-2delA		splice_acceptor intron	N/A	NP_001123538.1	B7ZCA0
	MIR5004	NR_049800.1		n.87delA		non_coding_transcript_exon	Exon 1 of 1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SYNGAP1	ENST00000646630.1	MANE Select	c.1387-2delA		splice_acceptor intron	N/A	ENSP00000496007.1	Q96PV0-1
	SYNGAP1	ENST00000644458.1		c.1387-2delA		splice_acceptor intron	N/A	ENSP00000495541.1	A0A2R8Y6T2
	SYNGAP1	ENST00000449372.7	TSL:5	c.1387-2delA		splice_acceptor intron	N/A	ENSP00000416519.4	B7ZCA0

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		9.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.87		Position offset: 16
DS_AL_spliceai		0.98		Position offset: 3

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

Other links and lift over

dbSNP: rs1760914246; hg19: chr6-33406193;