6-75137523-T-C

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4BS1_Supporting

The NM_004370.6(COL12A1):c.5308A>G(p.Thr1770Ala) variant causes a missense change. The variant allele was found at a frequency of 0.000247 in 1,613,680 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T1770I) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00016 ( 0 hom., cov: 31)

Exomes 𝑓: 0.00026 ( 0 hom. )

Consequence

COL12A1
NM_004370.6 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: 4.71

Publications

0 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 -2 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.37092683).

BS1

Variant frequency is greater than expected in population nfe. GnomAdExome4 allele frequency = 0.000256 (374/1461438) while in subpopulation NFE AF = 0.000326 (362/1111662). AF 95% confidence interval is 0.000298. There are 0 homozygotes in GnomAdExome4. There are 164 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.5308A>G	p.Thr1770Ala	missense_variant	Exon 31 of 66	ENST00000322507.13	NP_004361.3	Q99715-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
COL12A1	ENST00000322507.13 link	c.5308A>G	p.Thr1770Ala	missense_variant	Exon 31 of 66	1	NM_004370.6	ENSP00000325146.8		Q99715-1

Frequencies

GnomAD3 genomes

AF:

0.000158

AC:

AN:

152124

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

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:

0.000279

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000120

AC:

AN:

249254

AF XY:

0.000126

show subpopulations

Gnomad AFR exome

AF:

0.0000646

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:

0.000256

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000256

AC:

374

AN:

1461438

Hom.:

Cov.:

AF XY:

0.000226

AC XY:

164

AN XY:

727048

show subpopulations

African (AFR)

AF:

0.0000896

AC:

AN:

33472

American (AMR)

AF:

0.00

AC:

AN:

44716

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26128

East Asian (EAS)

AF:

0.00

AC:

AN:

39674

South Asian (SAS)

AF:

0.00

AC:

AN:

86226

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53416

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000326

AC:

362

AN:

1111662

Other (OTH)

AF:

0.000133

AC:

AN:

60376

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.466

Heterozygous variant carriers

107

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

100

<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:

0.000158

AC:

AN:

152242

Hom.:

Cov.:

AF XY:

0.000188

AC XY:

AN XY:

74440

show subpopulations

African (AFR)

AF:

0.000120

AC:

AN:

41556

American (AMR)

AF:

0.00

AC:

AN:

15292

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5160

South Asian (SAS)

AF:

0.00

AC:

AN:

4806

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10614

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000279

AC:

AN:

68022

Other (OTH)

AF:

0.00

AC:

AN:

2114

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.485

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:

0.000294

Hom.:

Bravo

AF:

0.000125

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000243

AC:

ExAC

AF:

0.000132

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:4

Nov 01, 2022

Revvity Omics, Revvity

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

May 28, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Has not been previously published as pathogenic or benign to our knowledge; In silico analysis indicates that this missense variant does not alter protein structure/function -

Dec 01, 2022

CeGaT Center for Human Genetics Tuebingen

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Apr 27, 2023

Mayo Clinic Laboratories, Mayo Clinic

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

BP4 -

Inborn genetic diseases

Uncertain:1

Jul 17, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.5308A>G (p.T1770A) alteration is located in exon 31 (coding exon 30) of the COL12A1 gene. This alteration results from a A to G substitution at nucleotide position 5308, causing the threonine (T) at amino acid position 1770 to be replaced by an alanine (A). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Bethlem myopathy 2;C4225314:Ullrich congenital muscular dystrophy 2

Uncertain:1

Dec 25, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces threonine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 1770 of the COL12A1 protein (p.Thr1770Ala). This variant is present in population databases (rs192345009, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with COL12A1-related conditions. ClinVar contains an entry for this variant (Variation ID: 567112). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt COL12A1 protein function with a negative predictive value of 80%. 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

Benign

0.20

BayesDel_addAF

Benign

-0.20

BayesDel_noAF

Benign

-0.23

CADD

Benign

(source)

DANN

Benign

0.95

DEOGEN2

Benign

0.025

T;T;.;.;.

Eigen

Benign

0.079

Eigen_PC

Benign

0.17

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.89

D;D;D;D;D

M_CAP

Benign

0.027

MetaRNN

Benign

0.37

T;T;T;T;T

MetaSVM

Benign

-0.94

MutationAssessor

Benign

1.8

.;L;.;L;.

PhyloP100

4.7

PrimateAI

Uncertain

0.74

PROVEAN

Benign

-1.3

.;N;N;N;N

REVEL

Benign

0.18

Sift

Benign

0.57

.;T;T;T;T

Sift4G

Benign

0.069

T;D;T;D;D

Polyphen

0.48, 0.26

.;P;B;.;.

Vest4

0.70

MVP

0.35

MPC

0.56

ClinPred

0.085

GERP RS

5.3

Varity_R

0.14

gMVP

0.65

Mutation Taster

=88/12

polymorphism

(source)

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

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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