3-101223195-C-T

Variant names:

• chr3-101223195-C-T
• rs773704860
• NM_016247.4:c.*3774G>A

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_Strong BS1_Supporting

The NM_016247.4(IMPG2):​c.*3774G>A variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000729 in 152,194 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00073 (1 hom., cov: 33)
  • Failed GnomAD Quality Control
• Consequence: IMPG2 NM_016247.4 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.146
• 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):

• IMPG2-related recessive retinopathy

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

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• vitelliform macular dystrophy 5

  Inheritance: Unknown, AD Classification: DEFINITIVE, LIMITED 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 -5 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.68).
• BS1: Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.000729 (111/152194) while in subpopulation NFE AF = 0.00126 (86/68016). AF 95% confidence interval is 0.00105. There are 1 homozygotes in GnomAd4. There are 46 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

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.*3774G>A		3_prime_UTR	Exon 19 of 19	NP_057331.2	Q9BZV3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	IMPG2	ENST00000193391.8	TSL:1 MANE Select	c.*3774G>A		3_prime_UTR	Exon 19 of 19	ENSP00000193391.6	Q9BZV3

Frequencies

GnomAD3 genomes AF: 0.000730 AC: 111 AN: 152076 Hom.: 1 Cov.: 33

Gnomad AFR AF: 0.0000725

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000327

Gnomad ASJ AF: 0.000576

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00123

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00126

Gnomad OTH AF: 0.000955

GnomAD4 exome Data not reliable, filtered out with message: AC0 AC: 0 AN: 0 Hom.: 0 Cov.: 0 AC XY: 0 AN XY: 0

African (AFR) AC: 0 AN: 0

American (AMR) AC: 0 AN: 0

Ashkenazi Jewish (ASJ) AC: 0 AN: 0

East Asian (EAS) AC: 0 AN: 0

South Asian (SAS) AC: 0 AN: 0

European-Finnish (FIN) AC: 0 AN: 0

Middle Eastern (MID) AC: 0 AN: 0

European-Non Finnish (NFE) AC: 0 AN: 0

Other (OTH) AC: 0 AN: 0

GnomAD4 genome AF: 0.000729 AC: 111 AN: 152194 Hom.: 1 Cov.: 33 AF XY: 0.000618 AC XY: 46 AN XY: 74402

African (AFR) AF: 0.0000722 AC: 3 AN: 41526

American (AMR) AF: 0.000327 AC: 5 AN: 15290

Ashkenazi Jewish (ASJ) AF: 0.000576 AC: 2 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5182

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

European-Finnish (FIN) AF: 0.00123 AC: 13 AN: 10568

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00126 AC: 86 AN: 68016

Other (OTH) AF: 0.000945 AC: 2 AN: 2116

Alfa AF: 0.00154 Hom.: 1

Bravo AF: 0.000480

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Retinitis pigmentosa (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.68
CADD	Benign	8.7
DANN	Benign	0.63
PhyloP100		0.15
Mutation Taster		=100/0	polymorphism

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: rs773704860; hg19: chr3-100942039;