chr1-40307451-G-T

Variant names:

• chr1-40307451-G-T
• rs2228567
• NM_001852.4:c.1003C>A

Variant summary

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

The NM_001852.4(COL9A2):​c.1003C>A​(p.Leu335Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,564 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. L335V) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: COL9A2 NM_001852.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.394
• Publications: 28 publications found

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]

COL9A2 Gene-Disease associations (from GenCC):

• epiphyseal dysplasia, multiple, 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• Stickler syndrome, type 5

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, Genomics England PanelApp, G2P
• 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_001852.4. 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
	COL9A2	NM_001852.4	MANE Select	c.1003C>A	p.Leu335Ile	missense	Exon 19 of 32	NP_001843.1	Q14055

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL9A2	ENST00000372748.8	TSL:1 MANE Select	c.1003C>A	p.Leu335Ile	missense	Exon 19 of 32	ENSP00000361834.3	Q14055
	COL9A2	ENST00000482722.5	TSL:1	n.1306C>A		non_coding_transcript_exon	Exon 18 of 31
	COL9A2	ENST00000869268.1		c.1003C>A	p.Leu335Ile	missense	Exon 19 of 32	ENSP00000539327.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461564 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727054

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

American (AMR) AF: 0.00 AC: 0 AN: 44666

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26128

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86196

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53394

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111882

Other (OTH) AF: 0.00 AC: 0 AN: 60356

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 775

Bravo AF: 0.00000378

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	0.094
BayesDel_addAF	Uncertain	0.015	T
BayesDel_noAF	Benign	-0.22
CADD	Benign	18
DANN	Uncertain	0.98
DEOGEN2	Benign	0.13	T
Eigen	Benign	0.0019
Eigen_PC	Benign	0.0082
FATHMM_MKL	Benign	0.75	D
LIST_S2	Benign	0.84	T
M_CAP	Uncertain	0.093	D
MetaRNN	Uncertain	0.42	T
MetaSVM	Uncertain	0.14	D
MutationAssessor	Benign	1.3	L
PhyloP100		0.39
PrimateAI	Uncertain	0.50	T
PROVEAN	Benign	-0.51	N
REVEL	Benign	0.23
Sift	Uncertain	0.027	D
Sift4G	Benign	0.19	T
Polyphen		0.90	P
Vest4		0.23
MutPred		0.35		Loss of catalytic residue at L335 (P = 0.1212)
MVP		0.88
MPC		0.71
ClinPred		0.72	D
GERP RS		3.0
Varity_R		0.13
gMVP		0.13
Mutation Taster		=98/2	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs2228567; hg19: chr1-40773123;