NM_000231.3:c.803C>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PP3_Moderate

The NM_000231.3(SGCG):​c.803C>T​(p.Pro268Leu) variant causes a missense change. The variant allele was found at a frequency of 0.0000173 in 1,613,834 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. P268P) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00012 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

SGCG
NM_000231.3 missense

Scores

4
11
4

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 4.22

Publications

1 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.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.888

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SGCGNM_000231.3 linkc.803C>T p.Pro268Leu missense_variant Exon 8 of 8 ENST00000218867.4 NP_000222.2 Q13326

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SGCGENST00000218867.4 linkc.803C>T p.Pro268Leu missense_variant Exon 8 of 8 1 NM_000231.3 ENSP00000218867.3 Q13326

Frequencies

GnomAD3 genomes
AF:
0.000118
AC:
18
AN:
152086
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000435
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000239
AC:
6
AN:
251470
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.000308
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000684
AC:
10
AN:
1461748
Hom.:
0
Cov.:
52
AF XY:
0.00000825
AC XY:
6
AN XY:
727168
show subpopulations
African (AFR)
AF:
0.000209
AC:
7
AN:
33478
American (AMR)
AF:
0.0000224
AC:
1
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53400
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5672
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1112008
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60378
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.485
Heterozygous variant carriers
0
1
2
2
3
4
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
AF:
0.000118
AC:
18
AN:
152086
Hom.:
0
Cov.:
32
AF XY:
0.0000808
AC XY:
6
AN XY:
74268
show subpopulations
African (AFR)
AF:
0.000435
AC:
18
AN:
41406
American (AMR)
AF:
0.00
AC:
0
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10590
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2084
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.458
Heterozygous variant carriers
0
2
3
5
6
8
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:
0.0000608
Hom.:
0
Bravo
AF:
0.000151
ESP6500AA
AF:
0.000681
AC:
3
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2C Uncertain:3
Sep 27, 2021
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 27, 2020
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jun 13, 2022
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 leucine, which is neutral and non-polar, at codon 268 of the SGCG protein (p.Pro268Leu). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with SGCG-related conditions. ClinVar contains an entry for this variant (Variation ID: 284977). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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 provided Uncertain:2
Jul 17, 2020
Athena Diagnostics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dec 11, 2015
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.097
BayesDel_addAF
Benign
-0.043
T
BayesDel_noAF
Uncertain
0.0
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.94
D
Eigen
Uncertain
0.41
Eigen_PC
Uncertain
0.37
FATHMM_MKL
Uncertain
0.87
D
LIST_S2
Uncertain
0.94
D
M_CAP
Pathogenic
0.34
D
MetaRNN
Pathogenic
0.89
D
MetaSVM
Uncertain
0.78
D
MutationAssessor
Uncertain
2.7
M
PhyloP100
4.2
PrimateAI
Uncertain
0.61
T
PROVEAN
Uncertain
-3.8
D
REVEL
Pathogenic
0.74
Sift
Uncertain
0.0060
D
Sift4G
Benign
0.065
T
Polyphen
0.82
P
Vest4
0.64
MVP
0.96
MPC
0.33
ClinPred
0.84
D
GERP RS
4.4
Varity_R
0.20
gMVP
0.69
Mutation Taster
=67/33
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.13
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: rs143110015; hg19: chr13-23898607; API