rs372188878

Variant summary

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

The NM_000231.3(SGCG):​c.670A>G​(p.Met224Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000397 in 1,613,600 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. M224I) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000040 ( 0 hom. )

Consequence

SGCG
NM_000231.3 missense

Scores

7
12

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 3.25

Publications

0 publications found
Variant links:
Genes affected
SGCG (HGNC:10809): (sarcoglycan gamma) This gene encodes gamma-sarcoglycan, one of several sarcolemmal transmembrane glycoproteins that interact with dystrophin. The dystrophin-glycoprotein complex (DGC) spans the sarcolemma and is comprised of dystrophin, syntrophin, alpha- and beta-dystroglycans and sarcoglycans. The DGC provides a structural link between the subsarcolemmal cytoskeleton and the extracellular matrix of muscle cells. Defects in the encoded protein can lead to early onset autosomal recessive muscular dystrophy, in particular limb-girdle muscular dystrophy, type 2C (LGMD2C). [provided by RefSeq, Oct 2008]
SACS (HGNC:10519): (sacsin molecular chaperone) This gene encodes the sacsin protein, which includes a UbL domain at the N-terminus, a DnaJ domain, and a HEPN domain at the C-terminus. The gene is highly expressed in the central nervous system, also found in skin, skeletal muscles and at low levels in the pancreas. This gene includes a very large exon spanning more than 12.8 kb. Mutations in this gene result in autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS), a neurodegenerative disorder characterized by early-onset cerebellar ataxia with spasticity and peripheral neuropathy. The authors of a publication on the effects of siRNA-mediated sacsin knockdown concluded that sacsin protects against mutant ataxin-1 and suggest that "the large multi-domain sacsin protein is able to recruit Hsp70 chaperone action and has the potential to regulate the effects of other ataxia proteins" (Parfitt et al., PubMed: 19208651). A pseudogene associated with this gene is located on chromosome 11. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, May 2013]
SACS Gene-Disease associations (from GenCC):
  • Charlevoix-Saguenay spastic ataxia
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Myriad Women’s Health

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SGCGNM_000231.3 linkc.670A>G p.Met224Val missense_variant Exon 7 of 8 ENST00000218867.4 NP_000222.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SGCGENST00000218867.4 linkc.670A>G p.Met224Val missense_variant Exon 7 of 8 1 NM_000231.3 ENSP00000218867.3
SACSENST00000682775.1 linkc.2186-8613T>C intron_variant Intron 9 of 9 ENSP00000508399.1
SACSENST00000683210.1 linkc.2186-31485T>C intron_variant Intron 9 of 9 ENSP00000506739.1
SACSENST00000684325.1 linkn.*104+838T>C intron_variant Intron 10 of 10 ENSP00000508121.1

Frequencies

GnomAD3 genomes
AF:
0.0000395
AC:
6
AN:
151962
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.0000242
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:
0.0000735
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000199
AC:
5
AN:
251320
AF XY:
0.0000221
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:
0.0000440
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000397
AC:
58
AN:
1461638
Hom.:
0
Cov.:
32
AF XY:
0.0000358
AC XY:
26
AN XY:
727128
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44716
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39690
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86238
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53398
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000522
AC:
58
AN:
1111848
Other (OTH)
AF:
0.00
AC:
0
AN:
60380
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.467
Heterozygous variant carriers
0
3
6
10
13
16
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
4
8
12
16
20
<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:
0.0000395
AC:
6
AN:
151962
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
74230
show subpopulations
African (AFR)
AF:
0.0000242
AC:
1
AN:
41342
American (AMR)
AF:
0.00
AC:
0
AN:
15234
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10578
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000735
AC:
5
AN:
68010
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.533
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000386
Hom.:
0
Bravo
AF:
0.0000227
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000330
AC:
4
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2C Uncertain:3
Nov 19, 2019
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nov 11, 2019
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Aug 27, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces methionine with valine at codon 224 of the SGCG protein (p.Met224Val). The methionine residue is moderately conserved and there is a small physicochemical difference between methionine and valine. This variant is present in population databases (rs372188878, ExAC 0.006%). This variant has not been reported in the literature in individuals affected with SGCG-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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
0.13
BayesDel_addAF
Uncertain
0.043
T
BayesDel_noAF
Uncertain
-0.070
CADD
Benign
11
DANN
Benign
0.46
DEOGEN2
Uncertain
0.64
D
Eigen
Benign
-0.45
Eigen_PC
Benign
-0.40
FATHMM_MKL
Benign
0.69
D
LIST_S2
Benign
0.70
T
M_CAP
Benign
0.043
D
MetaRNN
Uncertain
0.45
T
MetaSVM
Uncertain
-0.12
T
MutationAssessor
Uncertain
2.4
M
PhyloP100
3.3
PrimateAI
Benign
0.42
T
PROVEAN
Benign
-0.95
N
REVEL
Uncertain
0.41
Sift
Benign
0.16
T
Sift4G
Benign
0.31
T
Polyphen
0.27
B
Vest4
0.28
MVP
0.83
MPC
0.14
ClinPred
0.32
T
GERP RS
3.0
Varity_R
0.21
gMVP
0.50
Mutation Taster
=92/8
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

Publications

Other links and lift over

dbSNP: rs372188878; hg19: chr13-23894867; API