rs759284746

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2BP4_ModerateBP6

The NM_000023.4(SGCA):​c.58G>A​(p.Asp20Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000041 in 1,461,838 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D20Y) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

SGCA
NM_000023.4 missense

Scores

4
15

Clinical Significance

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

Conservation

PhyloP100: 1.18

Publications

0 publications found
Variant links:
Genes affected
SGCA (HGNC:10805): (sarcoglycan alpha) This gene encodes a component of the dystrophin-glycoprotein complex (DGC), which is critical to the stability of muscle fiber membranes and to the linking of the actin cytoskeleton to the extracellular matrix. Its expression is thought to be restricted to striated muscle. Mutations in this gene result in type 2D autosomal recessive limb-girdle muscular dystrophy. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2008]
SGCA Gene-Disease associations (from GenCC):
  • autosomal recessive limb-girdle muscular dystrophy
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • autosomal recessive limb-girdle muscular dystrophy type 2D
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Myriad Women’s Health, Laboratory for Molecular Medicine, Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.10131326).
BP6
Variant 17-50167388-G-A is Benign according to our data. Variant chr17-50167388-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 471336.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SGCANM_000023.4 linkc.58G>A p.Asp20Asn missense_variant Exon 2 of 10 ENST00000262018.8 NP_000014.1 Q16586-1A0A0S2Z4Q1
SGCANM_001135697.3 linkc.58G>A p.Asp20Asn missense_variant Exon 2 of 8 NP_001129169.1 Q16586-2A0A0S2Z4P8
SGCANR_135553.2 linkn.94G>A non_coding_transcript_exon_variant Exon 2 of 9

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SGCAENST00000262018.8 linkc.58G>A p.Asp20Asn missense_variant Exon 2 of 10 1 NM_000023.4 ENSP00000262018.3 Q16586-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000199
AC:
5
AN:
251274
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000145
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:
0.00000410
AC:
6
AN:
1461838
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
727212
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.000134
AC:
6
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86248
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53398
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111994
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
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

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
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000227
ExAC
AF:
0.0000165
AC:
2

ClinVar

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

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2D Uncertain:2
Nov 11, 2019
Natera, Inc.
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jul 19, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 20 of the SGCA protein (p.Asp20Asn). This variant is present in population databases (rs759284746, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with SGCA-related conditions. ClinVar contains an entry for this variant (Variation ID: 471336). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt SGCA protein function. 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. -

Arrhythmogenic right ventricular cardiomyopathy Benign:1
Aug 16, 2017
Center for Advanced Laboratory Medicine, UC San Diego Health, University of California San Diego
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.082
BayesDel_addAF
Benign
-0.19
T
BayesDel_noAF
Benign
-0.28
CADD
Benign
7.4
DANN
Uncertain
0.98
DEOGEN2
Uncertain
0.59
.;D
Eigen
Benign
-0.84
Eigen_PC
Benign
-0.88
FATHMM_MKL
Benign
0.25
N
LIST_S2
Benign
0.65
T;T
M_CAP
Uncertain
0.11
D
MetaRNN
Benign
0.10
T;T
MetaSVM
Uncertain
0.32
D
MutationAssessor
Benign
1.4
L;L
PhyloP100
1.2
PrimateAI
Benign
0.30
T
PROVEAN
Benign
0.090
N;N
REVEL
Benign
0.20
Sift
Benign
0.29
T;T
Sift4G
Benign
0.29
T;T
Polyphen
0.49
P;B
Vest4
0.15
MutPred
0.41
Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);
MVP
0.92
MPC
0.35
ClinPred
0.21
T
GERP RS
-0.41
Varity_R
0.033
gMVP
0.50

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.050
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: rs759284746; hg19: chr17-48244749; API