6-116120345-A-G

Position:

• chr6-116120345-A-G

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Moderate

The NM_000493.4(COL10A1):​c.1771T>C​(p.Cys591Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C591G) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL10A1 NM_000493.4 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 7.35

Genes affected

COL10A1 (HGNC:2185): (collagen type X alpha 1 chain) This gene encodes the alpha chain of type X collagen, a short chain collagen expressed by hypertrophic chondrocytes during endochondral ossification. Unlike type VIII collagen, the other short chain collagen, type X collagen is a homotrimer. Mutations in this gene are associated with Schmid type metaphyseal chondrodysplasia (SMCD) and Japanese type spondylometaphyseal dysplasia (SMD). [provided by RefSeq, Jul 2008]

NT5DC1 (HGNC:21556): (5'-nucleotidase domain containing 1) While the exact function of the protein encoded by this gene is not known, it belongs to the 5'(3')-deoxyribonucleotidase family. [provided by RefSeq, May 2010]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PM1: In a region_of_interest Nonhelical region (NC1) (size 160) in uniprot entity COAA1_HUMAN there are 9 pathogenic changes around while only 1 benign (90%) in NM_000493.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr6-116120345-A-C is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99
• PP5: Variant 6-116120345-A-G is Pathogenic according to our data. Variant chr6-116120345-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 17467.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
COL10A1	NM_000493.4	c.1771T>C	p.Cys591Arg	missense_variant	3/3	ENST00000651968.1	NP_000484.2
NT5DC1	NM_152729.3	c.529+2400A>G		intron_variant		ENST00000319550.9	NP_689942.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
COL10A1	ENST00000651968.1	c.1771T>C	p.Cys591Arg	missense_variant	3/3		NM_000493.4	ENSP00000498802.1
NT5DC1	ENST00000319550.9	c.529+2400A>G		intron_variant		1	NM_152729.3	ENSP00000326858.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 37

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Metaphyseal chondrodysplasia, Schmid type Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Feb 01, 1994

- -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 07, 2021

This variant is not present in population databases (ExAC no frequency). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This variant disrupts the p.Cys591 amino acid residue in COL10A1. Other variant(s) that disrupt this residue have been observed in individuals with COL10A1-related conditions (PMID: 30202406, Invitae), which suggests that this may be a clinically significant amino acid residue. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has been observed in individual(s) with metaphyseal chondrodysplasia, Schmid type (PMID: 8004099, 16088909, Invitae). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 17467). This sequence change replaces cysteine with arginine at codon 591 of the COL10A1 protein (p.Cys591Arg). The cysteine residue is highly conserved and there is a large physicochemical difference between cysteine and arginine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.43
CADD	Uncertain	25
DANN	Uncertain	0.98
DEOGEN2	Pathogenic	0.87	D;D
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.95	D;.
M_CAP	Pathogenic	0.30	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	0.96	D
MutationAssessor	Pathogenic	4.0	H;H
PrimateAI	Uncertain	0.78	T
PROVEAN	Uncertain	-3.4	D;D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.017	D;D
Sift4G	Uncertain	0.0020	D;D
Polyphen		1.0	D;D
Vest4		0.96
MutPred		0.97		Gain of disorder (P = 0.0295);Gain of disorder (P = 0.0295);
MVP		0.98
MPC		0.044
ClinPred		1.0	D
GERP RS		4.7
Varity_R		0.99
gMVP		0.89

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

Publications

LitVar

Other links and lift over

dbSNP: rs111033546; hg19: chr6-116441508;