rs757888349

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1PM2PM5PP3_ModeratePP5_Very_Strong

The NM_000023.4(SGCA):​c.220C>T​(p.Arg74Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,613,786 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R74Q) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

SGCA
NM_000023.4 missense

Scores

7
7
4

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 0.550

Publications

5 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: Pathogenic. The variant received 16 ACMG points.

PM1
In a hotspot region, there are 12 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_000023.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr17-50167645-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 579610.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.912
PP5
Variant 17-50167644-C-T is Pathogenic according to our data. Variant chr17-50167644-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 188811.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

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.220C>Tp.Arg74Trp
missense
Exon 3 of 10NP_000014.1
SGCA
NM_001135697.3
c.220C>Tp.Arg74Trp
missense
Exon 3 of 8NP_001129169.1
SGCA
NR_135553.2
n.256C>T
non_coding_transcript_exon
Exon 3 of 9

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
SGCA
ENST00000262018.8
TSL:1 MANE Select
c.220C>Tp.Arg74Trp
missense
Exon 3 of 10ENSP00000262018.3
SGCA
ENST00000344627.10
TSL:1
c.220C>Tp.Arg74Trp
missense
Exon 3 of 8ENSP00000345522.6
SGCA
ENST00000952408.1
c.310C>Tp.Arg104Trp
missense
Exon 3 of 10ENSP00000622467.1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152156
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
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:
0.00000799
AC:
2
AN:
250198
AF XY:
0.0000148
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000545
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000886
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000479
AC:
7
AN:
1461630
Hom.:
0
Cov.:
32
AF XY:
0.00000413
AC XY:
3
AN XY:
727128
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000504
AC:
2
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53198
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000360
AC:
4
AN:
1111974
Other (OTH)
AF:
0.00
AC:
0
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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:
0.00000657
AC:
1
AN:
152156
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74330
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41428
American (AMR)
AF:
0.0000654
AC:
1
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10614
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68012
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.000126
Hom.:
0
ExAC
AF:
0.0000165
AC:
2

ClinVar

ClinVar submissions as Germline
Significance:Pathogenic/Likely pathogenic
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
5
-
-
Autosomal recessive limb-girdle muscular dystrophy type 2D (5)
1
-
-
Autosomal recessive limb-girdle muscular dystrophy (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.14
BayesDel_addAF
Pathogenic
0.38
D
BayesDel_noAF
Pathogenic
0.30
CADD
Uncertain
25
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.94
D
Eigen
Benign
0.059
Eigen_PC
Benign
-0.072
FATHMM_MKL
Benign
0.41
N
LIST_S2
Uncertain
0.89
D
M_CAP
Uncertain
0.21
D
MetaRNN
Pathogenic
0.91
D
MetaSVM
Pathogenic
0.98
D
MutationAssessor
Uncertain
2.3
M
PhyloP100
0.55
PrimateAI
Uncertain
0.61
T
PROVEAN
Uncertain
-2.9
D
REVEL
Pathogenic
0.75
Sift
Uncertain
0.016
D
Sift4G
Uncertain
0.027
D
Polyphen
1.0
D
Vest4
0.64
MutPred
0.85
Gain of catalytic residue at L72 (P = 0.0312)
MVP
0.99
MPC
1.0
ClinPred
0.95
D
GERP RS
1.2
Varity_R
0.12
gMVP
0.88
Mutation Taster
=13/87
disease causing (ClinVar)

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: rs757888349; hg19: chr17-48245005; API