rs199693016

Variant names:

Your query was ambiguous. Multiple possible variants found:

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BS1_Supporting

The NM_004370.6(COL12A1):c.8501C>G(p.Pro2834Arg) variant causes a missense change. The variant allele was found at a frequency of 0.0000638 in 1,613,732 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000068 ( 0 hom. )

Consequence

COL12A1
NM_004370.6 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 6.43

Publications

5 publications found

Variant links:

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

COL12A1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 ACMG points.

BS1

Variant frequency is greater than expected in population mid. GnomAdExome4 allele frequency = 0.0000684 (100/1461544) while in subpopulation MID AF = 0.000694 (4/5766). AF 95% confidence interval is 0.000236. There are 0 homozygotes in GnomAdExome4. There are 61 alleles in the male GnomAdExome4 subpopulation. Median coverage is 31. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
COL12A1	NM_004370.6 link	c.8501C>G	p.Pro2834Arg	missense_variant	Exon 58 of 66	ENST00000322507.13	NP_004361.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL12A1	ENST00000322507.13 link	c.8501C>G	p.Pro2834Arg	missense_variant	Exon 58 of 66	1	NM_004370.6	ENSP00000325146.8

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152188

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.0000441

AC:

AN:

249184

AF XY:

0.0000518

show subpopulations

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:

0.0000973

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000684

AC:

100

AN:

1461544

Hom.:

Cov.:

AF XY:

0.0000839

AC XY:

AN XY:

727086

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33468

American (AMR)

AF:

0.00

AC:

AN:

44682

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26106

East Asian (EAS)

AF:

0.00

AC:

AN:

39694

South Asian (SAS)

AF:

0.00

AC:

AN:

86218

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53390

Middle Eastern (MID)

AF:

0.000694

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.0000774

AC:

AN:

1111828

Other (OTH)

AF:

0.000166

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.459

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152188

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74350

show subpopulations

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

African (AFR)

AF:

0.00

AC:

AN:

41446

American (AMR)

AF:

0.000131

AC:

AN:

15282

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5192

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68034

Other (OTH)

AF:

0.00

AC:

AN:

2090

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000000000000888178), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.392

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000906

Hom.:

Bravo

AF:

0.0000793

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000122

AC:

ExAC

AF:

0.0000579

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Bethlem myopathy 2;C4225314:Ullrich congenital muscular dystrophy 2

Uncertain:2

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 30, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with arginine, which is basic and polar, at codon 2834 of the COL12A1 protein (p.Pro2834Arg). This variant is present in population databases (rs199693016, gnomAD 0.009%). This missense change has been observed in individual(s) with clinical features of COL12A1-related conditions (PMID: 35903967; internal data). ClinVar contains an entry for this variant (Variation ID: 583345). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -

not specified

Uncertain:1

Jun 26, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: COL12A1 c.8501C>G (p.Pro2834Arg) results in a non-conservative amino acid change in the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function all suggest that this variant is likely to be disruptive. The variant allele was found at a frequency of 4.4e-05 in 249184 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in COL12A1 causing Ullrich congenital muscular dystrophy 2 (4.4e-05 vs 0.0035), allowing no conclusion about variant significance. c.8501C>G has been observed in individual(s) with clinical features of COL12A1-related disorders, including an individual suspected of a heritable connective tissue disorder (Steinle_2022, internal data). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 35903967, 35918752). ClinVar contains an entry for this variant (Variation ID: 583345). Based on the evidence outlined above, the variant was classified as uncertain significance. -

not provided

Uncertain:1

Jul 17, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Has been reported in a patient with symptoms of a connective tissue disorder (PMID: 35903967); In silico analysis indicates that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 35903967) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.17

BayesDel_addAF

Uncertain

0.073

BayesDel_noAF

Uncertain

0.070

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Benign

0.016

.;T;T;.;.;.

Eigen

Pathogenic

0.79

Eigen_PC

Pathogenic

0.77

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Benign

0.85

T;T;T;T;T;T

M_CAP

Uncertain

0.088

MetaRNN

Uncertain

0.69

D;D;D;D;D;D

MetaSVM

Uncertain

0.68

MutationAssessor

Uncertain

2.6

.;.;M;.;.;.

PhyloP100

6.4

PrimateAI

Uncertain

0.70

PROVEAN

Benign

0.54

N;.;N;N;N;N

REVEL

Uncertain

0.60

Sift

Benign

0.89

T;.;T;T;T;T

Sift4G

Benign

0.83

T;T;T;T;T;T

Polyphen

1.0

.;.;D;D;.;.

Vest4

0.32, 0.44, 0.36, 0.36, 0.36

MVP

0.65

MPC

1.4

ClinPred

0.38

GERP RS

5.7

Varity_R

0.13

gMVP

0.39

Mutation Taster

=48/52

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

Splicevardb

2.0

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over