3-101242820-G-T

Variant names:

• chr3-101242820-G-T
• rs267606875
• NM_016247.4:c.2890C>A

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP7

The NM_016247.4(IMPG2):​c.2890C>A​(p.Arg964Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,730 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. R964R) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: IMPG2 NM_016247.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.177
• Publications: 0 publications found

Genes affected

IMPG2 (HGNC:18362): (interphotoreceptor matrix proteoglycan 2) The protein encoded by this gene binds chondroitin sulfate and hyaluronan and is a proteoglycan. The encoded protein plays a role in the organization of the interphotoreceptor matrix and may promote the growth and maintenance of the light-sensitive photoreceptor outer segment. Defects in this gene are a cause of retinitis pigmentosa type 56 and maculopathy, IMPG2-related.[provided by RefSeq, Mar 2011]

IMPG2 Gene-Disease associations (from GenCC):

• vitelliform macular dystrophy 5

  Inheritance: AD, Unknown Classification: DEFINITIVE, LIMITED Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• inherited retinal dystrophy

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• retinitis pigmentosa 56

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• adult-onset foveomacular vitelliform dystrophy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• retinitis pigmentosa

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.39).
• BP7: Synonymous conserved (PhyloP=0.177 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_016247.4. 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
	IMPG2	NM_016247.4	MANE Select	c.2890C>A	p.Arg964Arg	synonymous	Exon 14 of 19	NP_057331.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IMPG2	ENST00000193391.8	TSL:1 MANE Select	c.2890C>A	p.Arg964Arg	synonymous	Exon 14 of 19	ENSP00000193391.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461730 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727172

African (AFR) AF: 0.00 AC: 0 AN: 33470

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39676

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111912

Other (OTH) AF: 0.0000166 AC: 1 AN: 60390

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.39
CADD	Benign	6.9
DANN	Benign	0.62
PhyloP100		0.18

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: rs267606875; hg19: chr3-100961664;