chr22-32801732-G-T

Position:

• chr22-32801732-G-T

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_Strong BS1_Supporting BS2

The NM_000362.5(TIMP3):​c.-270G>T variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00201 in 215,944 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 0.0017 (1 hom., cov: 32)
  • Exomes 𝑓: 0.0028 (0 hom.)
• Consequence: TIMP3 NM_000362.5 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.413

Genes affected

TIMP3 (HGNC:11822): (TIMP metallopeptidase inhibitor 3) This gene belongs to the TIMP gene family. The proteins encoded by this gene family are inhibitors of the matrix metalloproteinases, a group of peptidases involved in degradation of the extracellular matrix (ECM). Expression of this gene is induced in response to mitogenic stimulation and this netrin domain-containing protein is localized to the ECM. Mutations in this gene have been associated with the autosomal dominant disorder Sorsby's fundus dystrophy. [provided by RefSeq, Jul 2008]

SYN3 (HGNC:11496): (synapsin III) This gene is a member of the synapsin gene family. Synapsins encode neuronal phosphoproteins which associate with the cytoplasmic surface of synaptic vesicles. Family members are characterized by common protein domains, and they are implicated in synaptogenesis and the modulation of neurotransmitter release, suggesting a potential role in several neuropsychiatric diseases. The protein encoded by this gene shares the synapsin family domain model, with domains A, C, and E exhibiting the highest degree of conservation. The protein contains a unique domain J, located between domains C and E. Based on this gene's localization to 22q12.3, a possible schizophrenia susceptibility locus, and the established neurobiological roles of the synapsins, this family member may represent a candidate gene for schizophrenia. The TIMP3 gene is located within an intron of this gene and is transcribed in the opposite direction. Alternative splicing of this gene results in multiple splice variants that encode different isoforms. [provided by RefSeq, Oct 2008]

ACMG classification

Verdict is Benign. Variant got -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.78).
• BS1: Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.00166 (253/152182) while in subpopulation NFE AF= 0.00312 (212/67958). AF 95% confidence interval is 0.00278. There are 1 homozygotes in gnomad4. There are 120 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High AC in GnomAd4 at 253 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TIMP3	NM_000362.5	c.-270G>T		5_prime_UTR_variant	1/5	ENST00000266085.7
SYN3	NM_003490.4	c.711+63183C>A		intron_variant		ENST00000358763.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TIMP3	ENST00000266085.7	c.-270G>T		5_prime_UTR_variant	1/5	1	NM_000362.5	P1
SYN3	ENST00000358763.7	c.711+63183C>A		intron_variant		5	NM_003490.4	P1
SYN3	ENST00000462268.1	n.225+63183C>A		intron_variant, non_coding_transcript_variant		3

Frequencies

GnomAD3 genomes AF: 0.00166 AC: 253 AN: 152074 Hom.: 1 Cov.: 32

Gnomad AFR AF: 0.000410

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000196

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00198

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00312

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00282 AC: 180 AN: 63762 Hom.: 0 Cov.: 3 AF XY: 0.00292 AC XY: 97 AN XY: 33206

Gnomad4 AFR exome AF: 0.000597

Gnomad4 AMR exome AF: 0.000669

Gnomad4 ASJ exome AF: 0.000547

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00190

Gnomad4 NFE exome AF: 0.00350

Gnomad4 OTH exome AF: 0.00233

GnomAD4 genome AF: 0.00166 AC: 253 AN: 152182 Hom.: 1 Cov.: 32 AF XY: 0.00161 AC XY: 120 AN XY: 74396

Gnomad4 AFR AF: 0.000409

Gnomad4 AMR AF: 0.000196

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00198

Gnomad4 NFE AF: 0.00312

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000425 Hom.: 0

Bravo AF: 0.00173

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Sorsby fundus dystrophy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.78
CADD	Benign	6.4
DANN	Benign	0.65

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

Publications

LitVar

Other links and lift over

dbSNP: rs532843825; hg19: chr22-33197718;