2-19994297-A-G

Position:

• chr2-19994297-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PVS1_Moderate

The NM_002381.5(MATN3):​c.1405+2T>C variant causes a splice donor change. The variant allele was found at a frequency of 0.000107 in 1,601,780 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000053 (0 hom., cov: 33)
  • Exomes 𝑓: 0.00011 (0 hom.)
• Consequence: MATN3 NM_002381.5 splice_donor
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.25

Genes affected

MATN3 (HGNC:6909): (matrilin 3) This gene encodes a member of von Willebrand factor A domain containing protein family. This family of proteins is thought to be involved in the formation of filamentous networks in the extracellular matrices of various tissues. This protein contains two von Willebrand factor A domains; it is present in the cartilage extracellular matrix and has a role in the development and homeostasis of cartilage and bone. Mutations in this gene result in multiple epiphyseal dysplasia. [provided by RefSeq, Jul 2008]

WDR35-DT (HGNC:55818): (WDR35 divergent transcript)

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.075290896 fraction of the gene. Cryptic splice site detected, with MaxEntScore 7.1, offset of -34, new splice context is: aagGTcagc. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MATN3	NM_002381.5	c.1405+2T>C		splice_donor_variant		ENST00000407540.8
WDR35-DT	NR_110235.1	n.291+3803A>G		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MATN3	ENST00000407540.8	c.1405+2T>C		splice_donor_variant		1	NM_002381.5	P1
WDR35-DT	ENST00000416575.2	n.284+3803A>G		intron_variant, non_coding_transcript_variant		2

Frequencies

GnomAD3 genomes AF: 0.0000525 AC: 8 AN: 152240 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000882

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000568 AC: 14 AN: 246396 Hom.: 0 AF XY: 0.0000599 AC XY: 8 AN XY: 133590

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000293

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000333

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000107

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000113 AC: 164 AN: 1449540 Hom.: 0 Cov.: 28 AF XY: 0.000111 AC XY: 80 AN XY: 721606

Gnomad4 AFR exome AF: 0.0000301

Gnomad4 AMR exome AF: 0.0000450

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000351

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000131

Gnomad4 OTH exome AF: 0.000233

GnomAD4 genome AF: 0.0000525 AC: 8 AN: 152240 Hom.: 0 Cov.: 33 AF XY: 0.0000672 AC XY: 5 AN XY: 74380

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000882

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000247 Hom.: 0

Bravo AF: 0.0000680

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.00 AC: 0

ExAC AF: 0.0000331 AC: 4

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 09, 2022

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Experimental studies and prediction algorithms are not available or were not evaluated, and the effect of this variant on mRNA splicing is currently unknown. This variant has not been reported in the literature in individuals affected with MATN3-related conditions. This variant is present in population databases (rs764727429, gnomAD 0.01%). This sequence change falls in intron 7 of the MATN3 gene. It does not directly change the encoded amino acid sequence of the MATN3 protein. It affects a nucleotide within the consensus splice site. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Pathogenic	0.17
CADD	Pathogenic	27
DANN	Uncertain	0.98
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Pathogenic	0.97	D
MutationTaster	Benign	1.0	D;D
GERP RS		4.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs764727429; hg19: chr2-20194058;