rs1554188241

Variant names:

• chr6-75188511-T-A
• rs1554188241
• NM_004370.6:c.848A>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_004370.6(COL12A1):​c.848A>T​(p.Glu283Val) 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 Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: COL12A1 NM_004370.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.67
• Publications: 0 publications found

Genes affected

COL12A1 (HGNC:2188): (collagen type XII alpha 1 chain) This gene encodes the alpha chain of type XII collagen, a member of the FACIT (fibril-associated collagens with interrupted triple helices) collagen family. Type XII collagen is a homotrimer found in association with type I collagen, an association that is thought to modify the interactions between collagen I fibrils and the surrounding matrix. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2008]

COL12A1 Gene-Disease associations (from GenCC):

• Bethlem myopathy 2

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
• Bethlem myopathy 2

  Inheritance: AD Classification: STRONG, LIMITED Submitted by: Ambry Genetics, Illumina, Genomics England PanelApp
• Ullrich congenital muscular dystrophy 2

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• Bethlem myopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Ullrich congenital muscular dystrophy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.858

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL12A1	NM_004370.6	c.848A>T	p.Glu283Val	missense_variant	Exon 8 of 66	ENST00000322507.13	NP_004361.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL12A1	ENST00000322507.13	c.848A>T	p.Glu283Val	missense_variant	Exon 8 of 66	1	NM_004370.6	ENSP00000325146.8

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Bethlem myopathy 2;C4225314:Ullrich congenital muscular dystrophy 2 Uncertain:1

Oct 04, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals with COL12A1-related disease. This sequence change replaces glutamic acid with valine at codon 283 of the COL12A1 protein (p.Glu283Val). The glutamic acid residue is highly conserved and there is a moderate physicochemical difference between glutamic acid and valine. This variant is not present in population databases (ExAC no frequency). Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.47	T;.;.
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	D;D;D
M_CAP	Uncertain	0.24	D
MetaRNN	Pathogenic	0.86	D;D;D
MetaSVM	Pathogenic	0.86	D
MutationAssessor	Pathogenic	3.8	H;H;.
PhyloP100		7.7
PrimateAI	Uncertain	0.70	T
PROVEAN	Benign	-2.1	N;N;N
REVEL	Pathogenic	0.86
Sift	Uncertain	0.0030	D;D;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	D;.;.
Vest4		0.82
MutPred		0.67		Loss of disorder (P = 0.0112);Loss of disorder (P = 0.0112);Loss of disorder (P = 0.0112);
MVP		0.93
MPC		0.62
ClinPred		0.98	D
GERP RS		6.1
Varity_R		0.36
gMVP		0.91
Mutation Taster		=61/39	polymorphism

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

Other links and lift over

dbSNP: rs1554188241; hg19: chr6-75898227;