rs753966526

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4BP6

The NM_004369.4(COL6A3):​c.2306C>T​(p.Ala769Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000304 in 1,614,096 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000027 ( 0 hom. )

Consequence

COL6A3
NM_004369.4 missense

Scores

7
12

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:2B:1O:1

Conservation

PhyloP100: 0.871
Variant links:
Genes affected
COL6A3 (HGNC:2213): (collagen type VI alpha 3 chain) This gene encodes the alpha-3 chain, one of the three alpha chains of type VI collagen, a beaded filament collagen found in most connective tissues. The alpha-3 chain of type VI collagen is much larger than the alpha-1 and -2 chains. This difference in size is largely due to an increase in the number of subdomains, similar to von Willebrand Factor type A domains, that are found in the amino terminal globular domain of all the alpha chains. These domains have been shown to bind extracellular matrix proteins, an interaction that explains the importance of this collagen in organizing matrix components. Mutations in the type VI collagen genes are associated with Bethlem myopathy, a rare autosomal dominant proximal myopathy with early childhood onset. Mutations in this gene are also a cause of Ullrich congenital muscular dystrophy, also referred to as Ullrich scleroatonic muscular dystrophy, an autosomal recessive congenital myopathy that is more severe than Bethlem myopathy. Multiple transcript variants have been identified, but the full-length nature of only some of these variants has been described. [provided by RefSeq, Jun 2009]

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.40175).
BP6
Variant 2-237378827-G-A is Benign according to our data. Variant chr2-237378827-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 499099.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, not_provided=1, Uncertain_significance=2}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
COL6A3NM_004369.4 linkuse as main transcriptc.2306C>T p.Ala769Val missense_variant 6/44 ENST00000295550.9 NP_004360.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
COL6A3ENST00000295550.9 linkuse as main transcriptc.2306C>T p.Ala769Val missense_variant 6/441 NM_004369.4 ENSP00000295550 P1P12111-1

Frequencies

GnomAD3 genomes
AF:
0.0000591
AC:
9
AN:
152206
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000724
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:
0.0000882
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000438
AC:
11
AN:
251380
Hom.:
0
AF XY:
0.0000442
AC XY:
6
AN XY:
135890
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000327
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000792
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000274
AC:
40
AN:
1461890
Hom.:
0
Cov.:
33
AF XY:
0.0000289
AC XY:
21
AN XY:
727248
show subpopulations
Gnomad4 AFR exome
AF:
0.0000597
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000306
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
AF:
0.0000591
AC:
9
AN:
152206
Hom.:
0
Cov.:
33
AF XY:
0.0000672
AC XY:
5
AN XY:
74360
show subpopulations
Gnomad4 AFR
AF:
0.0000724
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000882
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.000100
Hom.:
0
Bravo
AF:
0.0000416
ExAC
AF:
0.0000412
AC:
5

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:2Benign:1Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Uncertain:2
Uncertain significance, criteria provided, single submitterclinical testingRevvity Omics, RevvityJun 08, 2021- -
Uncertain significance, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Dec 28, 2016- -
Tip-toe gait Pathogenic:1
Likely pathogenic, no assertion criteria providedclinical testingPractice for Gait Abnormalities, David Pomarino, Competency Network Toe Walking c/o Practice PomarinoNov 27, 2020Myopathy refers to diseases that affect skeletal Muscles. These diseases attack muscle fibers, making muscles weak. Inherited myopathies are often caused by inheriting an abnormal gene mutation from a parent that causes the disease. Symptoms of congenital myopathies usually start at birth or in early childhood, but may not appear until the teen years or even later in adulthood. Congenital myopathies are somewhat unique compared with other inherited myopathies, as weakness typically affects all muscles and is often not progressive. Symptoms are: Muscle weakness, most commonly of upper arms and shoulders and thighs, muscle cramps, stiffness and spasms, fatigue with exertion and lack of energy. Our patients all walk on tiptoe, so they show similar symptoms. When we genetically test them with our toe walking panel, we find that around 90 per cent of them have a genetic variant that explains their toe walking. These can be assigned, for example, to the area of myopathies (such as variants of the COL6A3 gene), the area of hereditary neuropathies (such as variants of the KMT2C gene) or the area of metabolic diseases (such as variants of the PYGM gene). In a smaller group of patients with almost identical symptoms, no abnormality is found in the genes of our panel, but spastic paraplegia can be detected. In another small group of our toe walkers, no abnormalities can be detected in the genes analysed in our toe walking panel, nor do they suffer from spastic paraplegia, as is also the case with healthy children. In contrast to these, however, they show a tiptoe gait. These patients suffer from infantile cerebral palsy, in which toe walking can also be observed. -
Bethlem myopathy 1A Benign:1
Likely benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpSep 04, 2023- -
Ullrich congenital muscular dystrophy 1A;CN029274:Bethlem myopathy 1A Other:1
not provided, no classification providedphenotyping onlyGenomeConnect - Invitae Patient Insights Network-Variant interpreted as Uncertain significance and reported on 10-10-2018 by Lab Invitae. GenomeConnect-Invitae Patient Insights Network assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. Registry team members make no attempt to reinterpret the clinical significance of the variant. Phenotypic details are available under supporting information. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.16
BayesDel_addAF
Benign
-0.12
T
BayesDel_noAF
Benign
-0.22
CADD
Benign
17
DANN
Uncertain
1.0
DEOGEN2
Benign
0.35
.;T;.;.;.
Eigen
Benign
0.031
Eigen_PC
Benign
-0.094
FATHMM_MKL
Benign
0.21
N
LIST_S2
Uncertain
0.91
D;D;.;D;D
M_CAP
Uncertain
0.088
D
MetaRNN
Benign
0.40
T;T;T;T;T
MetaSVM
Uncertain
0.0055
D
MutationAssessor
Uncertain
2.7
.;M;.;.;.
MutationTaster
Benign
1.0
N;N;N;N;N;N;N;N
PrimateAI
Benign
0.40
T
PROVEAN
Benign
-1.7
N;N;N;N;N
REVEL
Uncertain
0.44
Sift
Benign
0.18
T;T;T;T;T
Sift4G
Uncertain
0.015
D;D;D;D;D
Polyphen
1.0
D;P;D;.;.
Vest4
0.35
MutPred
0.58
.;Loss of catalytic residue at A769 (P = 0.094);.;.;.;
MVP
0.80
MPC
0.60
ClinPred
0.36
T
GERP RS
4.6
Varity_R
0.38
gMVP
0.60

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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs753966526; hg19: chr2-238287470; COSMIC: COSV55104699; API