6-75181048-A-C

Variant names:

• chr6-75181048-A-C
• rs780620827
• NM_004370.6:c.2055T>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_004370.6(COL12A1):​c.2055T>G​(p.Ser685Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000658 in 151,936 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Synonymous variant affecting the same amino acid position (i.e. S685S) has been classified as Likely benign.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: COL12A1 NM_004370.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.0650
• Publications: 1 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: Orphanet, Labcorp Genetics (formerly Invitae)
• 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 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004370.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL12A1	NM_004370.6	MANE Select	c.2055T>G	p.Ser685Arg	missense	Exon 11 of 66	NP_004361.3
	COL12A1	NM_001424113.1		c.2055T>G	p.Ser685Arg	missense	Exon 11 of 66	NP_001411042.1
	COL12A1	NM_001424114.1		c.2055T>G	p.Ser685Arg	missense	Exon 11 of 65	NP_001411043.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	COL12A1	ENST00000322507.13	TSL:1 MANE Select	c.2055T>G	p.Ser685Arg	missense	Exon 11 of 66	ENSP00000325146.8	Q99715-1
	COL12A1	ENST00000345356.10	TSL:1	c.73+21672T>G		intron	N/A	ENSP00000305147.9	Q99715-2
	COL12A1	ENST00000486533.1	TSL:1	n.1161T>G		non_coding_transcript_exon	Exon 4 of 5

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 151936 Hom.: 0 Cov.: 32

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

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 151936 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74218

African (AFR) AF: 0.00 AC: 0 AN: 41364

American (AMR) AF: 0.00 AC: 0 AN: 15258

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 5176

South Asian (SAS) AF: 0.00 AC: 0 AN: 4782

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10606

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67970

Other (OTH) AF: 0.00 AC: 0 AN: 2088

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.60
BayesDel_addAF	Benign	0.00070	T
BayesDel_noAF	Benign	-0.24
CADD	Benign	17
DANN	Uncertain	1.0
DEOGEN2	Benign	0.14	T
Eigen	Uncertain	0.25
Eigen_PC	Benign	0.21
FATHMM_MKL	Uncertain	0.87	D
LIST_S2	Uncertain	0.91	D
M_CAP	Benign	0.041	D
MetaRNN	Uncertain	0.56	D
MetaSVM	Benign	-0.85	T
MutationAssessor	Uncertain	2.6	M
PhyloP100		0.065
PrimateAI	Uncertain	0.51	T
PROVEAN	Benign	-1.3	N
REVEL	Uncertain	0.33
Sift	Uncertain	0.0040	D
Sift4G	Pathogenic	0.0010	D
Polyphen		0.95	P
Vest4		0.52
MutPred		0.58		Gain of catalytic residue at S685 (P = 0.0262)
MVP		0.57
MPC		0.53
ClinPred		0.90	D
GERP RS		2.4
Varity_R		0.30
gMVP		0.62
Mutation Taster		=76/24	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: rs780620827; hg19: chr6-75890764;