19-18790128-G-C

Position:

• chr19-18790128-G-C

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_Strong BS1_Supporting BS2

The NM_000095.3(COMP):​c.218-14C>G variant causes a splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000151 in 1,520,720 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 31)
  • Exomes 𝑓: 0.000015 (0 hom.)
• Consequence: COMP NM_000095.3 splice_polypyrimidine_tract, intron
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: -0.623

Genes affected

COMP (HGNC:2227): (cartilage oligomeric matrix protein) The protein encoded by this gene is a noncollagenous extracellular matrix (ECM) protein. It consists of five identical glycoprotein subunits, each with EGF-like and calcium-binding (thrombospondin-like) domains. Oligomerization results from formation of a five-stranded coiled coil and disulfides. Binding to other ECM proteins such as collagen appears to depend on divalent cations. Contraction or expansion of a 5 aa aspartate repeat and other mutations can cause pseudochondroplasia (PSACH) and multiple epiphyseal dysplasia (MED). [provided by RefSeq, Jul 2016]

ACMG classification

Verdict is Benign. Variant got -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.81).
• BS1: Variant frequency is greater than expected in population eas. gnomad4 allele frequency = 0.0000197 (3/151904) while in subpopulation EAS AF= 0.000389 (2/5140). AF 95% confidence interval is 0.0000688. There are 0 homozygotes in gnomad4. There are 2 alleles in male gnomad4 subpopulation. Median coverage is 31. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High AC in GnomAdExome4 at 20 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COMP	NM_000095.3	c.218-14C>G		splice_polypyrimidine_tract_variant, intron_variant		ENST00000222271.7	NP_000086.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COMP	ENST00000222271.7	c.218-14C>G		splice_polypyrimidine_tract_variant, intron_variant		1	NM_000095.3	ENSP00000222271	P1
COMP	ENST00000542601.6	c.119-14C>G		splice_polypyrimidine_tract_variant, intron_variant		1		ENSP00000439156
COMP	ENST00000425807.1	c.218-14C>G		splice_polypyrimidine_tract_variant, intron_variant		2		ENSP00000403792

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 151904 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: 0.000389

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000491 AC: 6 AN: 122210 Hom.: 0 AF XY: 0.0000750 AC XY: 5 AN XY: 66652

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000860

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000195

Gnomad SAS exome AF: 0.0000490

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000224

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000146 AC: 20 AN: 1368816 Hom.: 0 Cov.: 33 AF XY: 0.0000163 AC XY: 11 AN XY: 673146

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000579

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000113

Gnomad4 SAS exome AF: 0.0000129

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000112

Gnomad4 OTH exome AF: 0.0000176

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 151904 Hom.: 0 Cov.: 31 AF XY: 0.0000270 AC XY: 2 AN XY: 74188

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000389

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000227

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, single submitter

Submissions by phenotype

Pseudoachondroplastic spondyloepiphyseal dysplasia syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Multiple epiphyseal dysplasia type 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
CADD	Benign	2.1
DANN	Benign	0.24

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: rs150008764; hg19: chr19-18900937;