9-114156010-G-T

Variant names:

• chr9-114156010-G-T
• rs758537611
• NM_032888.4:c.60G>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Moderate BP6_Moderate

The NM_032888.4(COL27A1):​c.60G>T​(p.Gly20Gly) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000177 in 1,298,368 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★). Synonymous variant affecting the same amino acid position (i.e. G20G) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 0.000019 (0 hom.)
• Consequence: COL27A1 NM_032888.4 splice_region, synonymous
• Scores: Splicing: ADA: 0.01253
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 2.69
• Publications: 0 publications found

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]

COL27A1 Gene-Disease associations (from GenCC):

• Steel syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.45).
• BP6: Variant 9-114156010-G-T is Benign according to our data. Variant chr9-114156010-G-T is described in ClinVar as [Likely_benign]. Clinvar id is 1426698.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL27A1	NM_032888.4	c.60G>T	p.Gly20Gly	splice_region_variant, synonymous_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.60G>T	p.Gly20Gly	splice_region_variant, synonymous_variant	Exon 1 of 61	1	NM_032888.4	ENSP00000348385.3

Frequencies

GnomAD3 genomes AF: 0.00000659 AC: 1 AN: 151684 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000105 AC: 1 AN: 95358 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: 0.0000192

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000192 AC: 22 AN: 1146684 Hom.: 0 Cov.: 31 AF XY: 0.0000255 AC XY: 14 AN XY: 549788

African (AFR) AF: 0.00 AC: 0 AN: 24702

American (AMR) AF: 0.00 AC: 0 AN: 17312

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 15152

East Asian (EAS) AF: 0.00 AC: 0 AN: 30450

South Asian (SAS) AF: 0.00 AC: 0 AN: 26606

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 29698

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4580

European-Non Finnish (NFE) AF: 0.0000210 AC: 20 AN: 952298

Other (OTH) AF: 0.0000436 AC: 2 AN: 45886

GnomAD4 genome AF: 0.00000659 AC: 1 AN: 151684 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74102

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41388

American (AMR) AF: 0.00 AC: 0 AN: 15240

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3466

East Asian (EAS) AF: 0.00 AC: 0 AN: 5138

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10460

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 314

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67860

Other (OTH) AF: 0.00 AC: 0 AN: 2074

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000151

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Benign:1

Jan 29, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.45
CADD	Benign	16
DANN	Benign	0.96
PhyloP100		2.7
PromoterAI		0.059	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.2

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.013
dbscSNV1_RF	Benign	0.26
SpliceAI score (max)		0.25		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.25		Position offset: -2

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

Other links and lift over

dbSNP: rs758537611; hg19: chr9-116918290;