1-40301194-G-A

Variant summary

Our verdict is Benign. Variant got -10 ACMG points: 0P and 10B. BP4_Strong BP6 BP7 BS1

The NM_001852.4(COL9A2):c.2058C>T(p.Ile686=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000552 in 1,613,612 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00032 (1 hom., cov: 32)
  • Exomes 𝑓: 0.000028 (1 hom.)
• Consequence: COL9A2 NM_001852.4 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:2
• Conservation: PhyloP100: 0.908

Genes affected

COL9A2 (HGNC:2218): (collagen type IX alpha 2 chain) This gene encodes one of the three alpha chains of type IX collagen, the major collagen component of hyaline cartilage. Type IX collagen, a heterotrimeric molecule, is usually found in tissues containing type II collagen, a fibrillar collagen. This chain is unusual in that, unlike the other two type IX alpha chains, it contains a covalently attached glycosaminoglycan side chain. Mutations in this gene are associated with multiple epiphyseal dysplasia. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Benign. Variant got -10 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.47).
• BP6: Variant 1-40301194-G-A is Benign according to our data. Variant chr1-40301194-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 291230.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1, Benign=1}.
• BP7: Synonymous conserved (PhyloP=0.908 with no splicing effect.
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.000315 (48/152318) while in subpopulation AFR AF= 0.00111 (46/41572). AF 95% confidence interval is 0.000852. There are 1 homozygotes in gnomad4. There are 22 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL9A2	NM_001852.4	c.2058C>T	p.Ile686=	synonymous_variant	32/32	ENST00000372748.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL9A2	ENST00000372748.8	c.2058C>T	p.Ile686=	synonymous_variant	32/32	1	NM_001852.4	P1
COL9A2	ENST00000482722.5	n.2361C>T		non_coding_transcript_exon_variant	31/31	1

Frequencies

GnomAD3 genomes AF: 0.000315 AC: 48 AN: 152200 Hom.: 1 Cov.: 32

Gnomad AFR AF: 0.00111

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.000132 AC: 33 AN: 250448 Hom.: 1 AF XY: 0.0000959 AC XY: 13 AN XY: 135618

Gnomad AFR exome AF: 0.00174

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000490

GnomAD4 exome AF: 0.0000281 AC: 41 AN: 1461294 Hom.: 1 Cov.: 31 AF XY: 0.0000316 AC XY: 23 AN XY: 726960

Gnomad4 AFR exome AF: 0.00105

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.0000497

GnomAD4 genome AF: 0.000315 AC: 48 AN: 152318 Hom.: 1 Cov.: 32 AF XY: 0.000295 AC XY: 22 AN XY: 74484

Gnomad4 AFR AF: 0.00111

Gnomad4 AMR AF: 0.000131

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000212 Hom.: 0

Bravo AF: 0.000423

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1 Benign:1

Benign, criteria provided, single submitter	clinical testing	Invitae	Jan 28, 2024	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Sep 20, 2016	- -

Epiphyseal dysplasia, multiple, 2 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 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 and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.47
Cadd	Benign	7.7
Dann	Benign	0.78

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: rs115675008; hg19: chr1-40766866;