NM_001851.6:c.2684C>G

Variant names:

• chr6-70216979-G-C
• rs758916884
• NM_001851.6:c.2684C>G

Variant summary

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

The NM_001851.6(COL9A1):​c.2684C>G​(p.Pro895Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,614,044 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P895L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: COL9A1 NM_001851.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.39
• Publications: 0 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

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.2684C>G	p.Pro895Arg	missense	Exon 38 of 38	NP_001842.3
	COL9A1	NM_001377289.1		c.1985C>G	p.Pro662Arg	missense	Exon 33 of 33	NP_001364218.1	A0A804HIB6
	COL9A1	NM_078485.4		c.1955C>G	p.Pro652Arg	missense	Exon 32 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.2684C>G	p.Pro895Arg	missense	Exon 38 of 38	ENSP00000349790.6	P20849-1
	COL9A1	ENST00000320755.12	TSL:1	c.1955C>G	p.Pro652Arg	missense	Exon 32 of 32	ENSP00000315252.7	P20849-2
	COL9A1	ENST00000683980.2		c.1985C>G	p.Pro662Arg	missense	Exon 33 of 33	ENSP00000506990.1	A0A804HIB6

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152182 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

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

GnomAD2 exomes AF: 0.00000400 AC: 1 AN: 250270 AF XY: 0.00000738

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461862 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727226

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44722

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

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53402

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112006

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152182 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74346

African (AFR) AF: 0.00 AC: 0 AN: 41446

American (AMR) AF: 0.00 AC: 0 AN: 15286

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.000193 AC: 1 AN: 5182

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10626

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68028

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.0000468 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.091
BayesDel_addAF	Uncertain	0.020	T
BayesDel_noAF	Uncertain	-0.040
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.24	T
Eigen	Uncertain	0.50
Eigen_PC	Uncertain	0.52
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.80	T
M_CAP	Uncertain	0.10	D
MetaRNN	Uncertain	0.49	T
MetaSVM	Uncertain	0.57	D
MutationAssessor	Benign	1.9	M
PhyloP100		8.4
PrimateAI	Uncertain	0.55	T
PROVEAN	Benign	-2.0	N
REVEL	Uncertain	0.51
Sift	Benign	0.95	T
Sift4G	Benign	0.62	T
Polyphen		0.99	D
Vest4		0.40
MutPred		0.43		Loss of glycosylation at P895 (P = 0.0072)
MVP		0.98
MPC		0.40
ClinPred		0.97	D
GERP RS		5.9
Varity_R		0.11
gMVP		0.39
Mutation Taster		=32/68	disease causing

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: rs758916884; hg19: chr6-70926682;