20-62836198-A-G

Variant names:

• chr20-62836198-A-G
• NM_001853.4:c.1413A>G
• COL9A3 p.Arg471Arg

Variant summary

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

The NM_001853.4(COL9A3):​c.1413A>G​(p.Arg471Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 34)
• Consequence: COL9A3 NM_001853.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.60
• Publications: 0 publications found

Genes affected

COL9A3 (HGNC:2219): (collagen type IX alpha 3 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. Mutations in this gene are associated with multiple epiphyseal dysplasia type 3. [provided by RefSeq, Jan 2010]

COL9A3 Gene-Disease associations (from GenCC):

• epiphyseal dysplasia, multiple, 3

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Illumina, Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• Stickler syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, LIMITED Submitted by: Genomics England PanelApp, ClinGen, Ambry Genetics
• Stickler syndrome, type 6

  Inheritance: AR Classification: DEFINITIVE, STRONG, LIMITED Submitted by: G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• multiple epiphyseal dysplasia due to collagen 9 anomaly

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal recessive Stickler syndrome

  Inheritance: AR 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=-0.42).
• BP7: Synonymous conserved (PhyloP=1.6 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001853.4. 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
	COL9A3	NM_001853.4	MANE Select	c.1413A>G	p.Arg471Arg	synonymous	Exon 28 of 32	NP_001844.3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL9A3	ENST00000649368.1	MANE Select	c.1413A>G	p.Arg471Arg	synonymous	Exon 28 of 32	ENSP00000496793.1	Q14050
	COL9A3	ENST00000934236.1		c.1464A>G	p.Arg488Arg	synonymous	Exon 29 of 33	ENSP00000604295.1
	COL9A3	ENST00000894732.1		c.1341A>G	p.Arg447Arg	synonymous	Exon 27 of 31	ENSP00000564791.1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 34

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.42
CADD	Benign	9.7
DANN	Benign	0.84
PhyloP100		1.6

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr20-61467550;