rs2274584

chr6-70252336-C-Achr6-70252336-C-Gchr6-70252336-C-T

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 2P and 8B. PM2 BP4_Strong BS1

The NM_001851.6(COL9A1):c.1765-21G>T variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000888 in 1,611,078 control chromosomes in the GnomAD database, with no homozygous occurrence. 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: 𝑓 0.00049 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000047 (0 hom.)
• Consequence: COL9A1 NM_001851.6 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.0310

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]

ACMG classification

Verdict is Likely_benign. Variant got -6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.8).
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.000486 (74/152202) while in subpopulation AFR AF= 0.00149 (62/41550). AF 95% confidence interval is 0.00119. There are 0 homozygotes in gnomad4. There are 41 alleles in male gnomad4 subpopulation. This position pass quality control queck.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
COL9A1	NM_001851.6	c.1765-21G>T		intron_variant		ENST00000357250.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
COL9A1	ENST00000357250.11	c.1765-21G>T		intron_variant		1	NM_001851.6	P1

Frequencies

GnomAD3 genomes AF: 0.000487 AC: 74 AN: 152084 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00150

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000655

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: 0.000955

GnomAD3 exomes AF: 0.000124 AC: 31 AN: 250830 Hom.: 0 AF XY: 0.0000885 AC XY: 12 AN XY: 135548

Gnomad AFR exome AF: 0.00136

Gnomad AMR exome AF: 0.000174

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: 0.0000473 AC: 69 AN: 1458876 Hom.: 0 Cov.: 33 AF XY: 0.0000386 AC XY: 28 AN XY: 725910

Gnomad4 AFR exome AF: 0.00150

Gnomad4 AMR exome AF: 0.000246

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: 0.00000180

Gnomad4 OTH exome AF: 0.0000995

GnomAD4 genome AF: 0.000486 AC: 74 AN: 152202 Hom.: 0 Cov.: 32 AF XY: 0.000551 AC XY: 41 AN XY: 74402

Gnomad4 AFR AF: 0.00149

Gnomad4 AMR AF: 0.000654

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: 0.000945

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.80
Cadd	Benign	1.4
Dann	Benign	0.55

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: rs2274584; hg19: chr6-70962039;