NM_032888.4:c.52delG

Variant names:

• chr9-114156000-CG-C
• NM_032888.4:c.52delG

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_032888.4(COL27A1):​c.52delG​(p.Ala18ArgfsTer12) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000524 in 1,144,564 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000052 (0 hom.)
• Consequence: COL27A1 NM_032888.4 frameshift
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.81

Genes affected

COL27A1 (HGNC:22986): (collagen type XXVII alpha 1 chain) This gene encodes a member of the fibrillar collagen family, and plays a role during the calcification of cartilage and the transition of cartilage to bone. The encoded protein product is a preproprotein. It includes an N-terminal signal peptide, which is followed by an N-terminal propetide, mature peptide and a C-terminal propeptide. The N-terminal propeptide contains thrombospondin N-terminal-like and laminin G-like domains. The mature peptide is a major triple-helical region. The C-terminal propeptide, also known as COLFI domain, plays crucial roles in tissue growth and repair. Mutations in this gene cause Steel syndrome. Alternatively spliced transcript variants have been found, but the full-length nature of some variants has not been determined. [provided by RefSeq, Sep 2014]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 4 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL27A1	NM_032888.4	c.52delG	p.Ala18ArgfsTer12	frameshift_variant	Exon 1 of 61	ENST00000356083.8	NP_116277.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL27A1	ENST00000356083.8	c.52delG	p.Ala18ArgfsTer12	frameshift_variant	Exon 1 of 61	1	NM_032888.4	ENSP00000348385.3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000524 AC: 6 AN: 1144564 Hom.: 0 Cov.: 31 AF XY: 0.00000729 AC XY: 4 AN XY: 548672

Gnomad4 AFR exome AF: 0.0000405

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.0000694

Gnomad4 NFE exome AF: 0.00000315

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr9-116918280;