6-70232616-G-A

Variant names:

• chr6-70232616-G-A
• rs34119578
• NM_001851.6:c.2470C>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_001851.6(COL9A1):​c.2470C>T​(p.Pro824Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,786 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P824T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: COL9A1 NM_001851.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.96
• Publications: 5 publications found

Genes affected

COL9A1 (HGNC:2217): (collagen type IX alpha 1 chain) This gene encodes one of the three alpha chains of type IX collagen, which is a minor (5-20%) collagen component of hyaline cartilage. Type IX collagen is usually found in tissues containing type II collagen, a fibrillar collagen. Studies in knockout mice have shown that synthesis of the alpha 1 chain is essential for assembly of type IX collagen molecules, a heterotrimeric molecule, and that lack of type IX collagen is associated with early onset osteoarthritis. Mutations in this gene are associated with osteoarthritis in humans, with multiple epiphyseal dysplasia, 6, a form of chondrodysplasia, and with Stickler syndrome, a disease characterized by ophthalmic, orofacial, articular, and auditory defects. Two transcript variants that encode different isoforms have been identified for this gene. [provided by RefSeq, Jul 2008]

COL9A1 Gene-Disease associations (from GenCC):

• Stickler syndrome, type 4

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Genomics England PanelApp, ClinGen, Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• epiphyseal dysplasia, multiple, 6

  Inheritance: Unknown, AD, AR Classification: DEFINITIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• 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
• Stickler syndrome

  Inheritance: AR Classification: LIMITED Submitted by: ClinGen

ENSG00000253809 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001851.6. 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
	COL9A1	NM_001851.6	MANE Select	c.2470C>T	p.Pro824Ser	missense	Exon 36 of 38	NP_001842.3
	COL9A1	NM_001377289.1		c.1771C>T	p.Pro591Ser	missense	Exon 31 of 33	NP_001364218.1	A0A804HIB6
	COL9A1	NM_078485.4		c.1741C>T	p.Pro581Ser	missense	Exon 30 of 32	NP_511040.2	P20849-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL9A1	ENST00000357250.11	TSL:1 MANE Select	c.2470C>T	p.Pro824Ser	missense	Exon 36 of 38	ENSP00000349790.6	P20849-1
	COL9A1	ENST00000320755.12	TSL:1	c.1741C>T	p.Pro581Ser	missense	Exon 30 of 32	ENSP00000315252.7	P20849-2
	COL9A1	ENST00000683980.2		c.1771C>T	p.Pro591Ser	missense	Exon 31 of 33	ENSP00000506990.1	A0A804HIB6

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251296 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461786 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727174

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53372

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5724

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112008

Other (OTH) AF: 0.0000166 AC: 1 AN: 60390

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.11
CADD	Uncertain	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.71	D
Eigen	Pathogenic	0.72
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.83	T
M_CAP	Uncertain	0.12	D
MetaRNN	Uncertain	0.59	D
MetaSVM	Pathogenic	0.95	D
MutationAssessor	Benign	0.59	N
PhyloP100		10
PrimateAI	Uncertain	0.59	T
PROVEAN	Uncertain	-3.4	D
REVEL	Uncertain	0.52
Sift	Benign	0.061	T
Sift4G	Benign	0.28	T
Polyphen		1.0	D
Vest4		0.47
MutPred		0.34		Gain of phosphorylation at P824 (P = 0.0184)
MVP		0.97
MPC		0.40
ClinPred		0.87	D
GERP RS		5.8
Varity_R		0.18
gMVP		0.74
Mutation Taster		=51/49	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: rs34119578; hg19: chr6-70942319; COSMIC: COSV57885417; COSMIC: COSV57885417;