rs748936034

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PP3PP4PM5_Supporting

This summary comes from the ClinGen Evidence Repository: The NM_000023.4: c.661C>T variant in SGCA is a missense variant predicted to cause substitution of arginine by cysteine at amino acid 221 (p.Arg221Cys). This variant has been identified in at least five individuals with clinical signs of limb girdle muscular dystrophy (PMID:35416532, 28403181, 30564623; LOVD SGCA_000169) (PP4). The highest minor allele frequency of this variant is 0.0002940 (9/30612 exome chromosomes) in the South Asian population of gnomAD v2.1.1, which is greater than the ClinGen LGMD VCEP threshold (0.00009) for PM2_Supporting (criterion not met). The computational predictor REVEL gives a score of 0.787, which is above the VCEP threshold of ≥0.70, evidence that correlates with impact to SGCA function (PP3). In addition, another missense variant at the same codon, c.662G>C (p.Arg221Pro), has been classified as likely pathogenic for autosomal recessive limb girdle muscular dystrophy by the LGMD VCEP (PM5_Supporting). In summary, this variant cannot be classified as pathogenic nor benign at this time and remains a variant of uncertain significance for autosomal recessive limb girdle muscular dystrophy based on the ACMG/AMP criteria applied, as specified by the ClinGen LGMD VCEP (LGMD VCEP specifications version 1.0.0; 01/07/2025): PP4, PP3, PM5_Supporting. LINK:https://erepo.genome.network/evrepo/ui/classification/CA8643859/MONDO:0015152/189

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000031 ( 0 hom. )

Consequence

SGCA
NM_000023.4 missense

Scores

6
12

Clinical Significance

Uncertain significance reviewed by expert panel P:5U:6

Conservation

PhyloP100: 3.39

Publications

2 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: Uncertain_significance. The variant received 3 ACMG points.

PM5
For more information check the summary or visit ClinGen Evidence Repository.
PP3
For more information check the summary or visit ClinGen Evidence Repository.
PP4
For more information check the summary or visit ClinGen Evidence Repository.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000023.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
SGCA
NM_000023.4
MANE Select
c.661C>Tp.Arg221Cys
missense
Exon 6 of 10NP_000014.1
SGCA
NM_001135697.3
c.584+596C>T
intron
N/ANP_001129169.1
SGCA
NR_135553.2
n.697C>T
non_coding_transcript_exon
Exon 6 of 9

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
SGCA
ENST00000262018.8
TSL:1 MANE Select
c.661C>Tp.Arg221Cys
missense
Exon 6 of 10ENSP00000262018.3
SGCA
ENST00000344627.10
TSL:1
c.584+596C>T
intron
N/AENSP00000345522.6
SGCA
ENST00000952408.1
c.751C>Tp.Arg251Cys
missense
Exon 6 of 10ENSP00000622467.1

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152114
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000827
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000597
AC:
15
AN:
251336
AF XY:
0.0000736
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:
0.0000528
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000315
AC:
46
AN:
1461788
Hom.:
0
Cov.:
32
AF XY:
0.0000413
AC XY:
30
AN XY:
727200
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
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:
0.000336
AC:
29
AN:
86256
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53366
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.0000126
AC:
14
AN:
1111972
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.489
Heterozygous variant carriers
0
4
8
11
15
19
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:
0.0000394
AC:
6
AN:
152114
Hom.:
0
Cov.:
31
AF XY:
0.0000538
AC XY:
4
AN XY:
74302
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41428
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5174
South Asian (SAS)
AF:
0.000827
AC:
4
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68006
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.542
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

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:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.0000824
AC:
10

ClinVar

ClinVar submissions as Germline
Significance:Uncertain significance
Revision:reviewed by expert panel
View on ClinVar
Pathogenic
VUS
Benign
Condition
3
3
-
Autosomal recessive limb-girdle muscular dystrophy type 2D (6)
1
2
-
not provided (3)
1
1
-
Autosomal recessive limb-girdle muscular dystrophy (2)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.40
BayesDel_addAF
Uncertain
0.053
T
BayesDel_noAF
Pathogenic
0.14
CADD
Pathogenic
28
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.89
D
Eigen
Uncertain
0.60
Eigen_PC
Uncertain
0.58
FATHMM_MKL
Uncertain
0.83
D
LIST_S2
Uncertain
0.89
D
M_CAP
Uncertain
0.22
D
MetaRNN
Pathogenic
0.95
D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Uncertain
2.5
M
PhyloP100
3.4
PrimateAI
Uncertain
0.53
T
PROVEAN
Uncertain
-2.9
D
REVEL
Pathogenic
0.79
Sift
Uncertain
0.0010
D
Sift4G
Uncertain
0.0030
D
Polyphen
1.0
D
Vest4
0.68
MutPred
0.87
Loss of disorder (P = 0.0179)
MVP
0.99
MPC
1.3
ClinPred
0.57
D
GERP RS
5.1
Varity_R
0.20
gMVP
0.75
Mutation Taster
=30/70
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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: rs748936034; hg19: chr17-48246529; API