rs200671745

Positions:

• chr5-156344645-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BS1_Supporting

The NM_000337.6(SGCD):​c.160A>G​(p.Ile54Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000211 in 1,608,732 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.000092 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000014 (0 hom.)
• Consequence: SGCD NM_000337.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:10
• Conservation: PhyloP100: 9.20

Genes affected

SGCD (HGNC:10807): (sarcoglycan delta) The protein encoded by this gene is one of the four known components of the sarcoglycan complex, which is a subcomplex of the dystrophin-glycoprotein complex (DGC). DGC forms a link between the F-actin cytoskeleton and the extracellular matrix. This protein is expressed most abundantly in skeletal and cardiac muscle. Mutations in this gene have been associated with autosomal recessive limb-girdle muscular dystrophy and dilated cardiomyopathy. Alternatively spliced transcript variants encoding distinct isoforms have been observed for this gene. [provided by RefSeq, Jul 2008]

LOC124901120 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.0000919 (14/152272) while in subpopulation AFR AF= 0.000289 (12/41556). AF 95% confidence interval is 0.000166. There are 0 homozygotes in gnomad4. There are 9 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SGCD	NM_000337.6	c.160A>G	p.Ile54Val	missense_variant	3/9	ENST00000337851.9	NP_000328.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SGCD	ENST00000337851.9	c.160A>G	p.Ile54Val	missense_variant	3/9	1	NM_000337.6	ENSP00000338343.4
SGCD	ENST00000435422.7	c.157A>G	p.Ile53Val	missense_variant	2/8	1		ENSP00000403003.2
SGCD	ENST00000517913.5	c.160A>G	p.Ile54Val	missense_variant	5/10	5		ENSP00000429378.1
SGCD	ENST00000524347.2	n.160A>G		non_coding_transcript_exon_variant	3/6	5		ENSP00000430794.1

Frequencies

GnomAD3 genomes AF: 0.0000920 AC: 14 AN: 152154 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000290

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000534 AC: 13 AN: 243252 Hom.: 0 AF XY: 0.0000454 AC XY: 6 AN XY: 132084

Gnomad AFR exome AF: 0.000729

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000180

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000137 AC: 20 AN: 1456460 Hom.: 0 Cov.: 32 AF XY: 0.00000690 AC XY: 5 AN XY: 724244

Gnomad4 AFR exome AF: 0.000422

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000451

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000919 AC: 14 AN: 152272 Hom.: 0 Cov.: 32 AF XY: 0.000121 AC XY: 9 AN XY: 74456

Gnomad4 AFR AF: 0.000289

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000658 Hom.: 0

Bravo AF: 0.000106

ExAC AF: 0.0000414 AC: 5

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:10

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:4

Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Aug 10, 2018	- -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jun 30, 2023	In silico analysis supports that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 31983221, 19781108) -
Uncertain significance, no assertion criteria provided	clinical testing	Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)	-	- -
Uncertain significance, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -

not specified Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Mar 22, 2022	Variant summary: SGCD c.160A>G (p.Ile54Val) results in a conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 5.8e-05 in 274650 control chromosomes, predominantly at a frequency of 0.00059 within the African or African-American subpopulation in the gnomAD database. This frequency is not significantly higher than expected for a pathogenic variant in SGCD causing Limb-Girdle Muscular Dystrophy, Autosomal Recessive (5.8e-05 vs 0.00072), allowing no conclusion about variant significance. c.160A>G has been reported in the literature in individuals affected with Dilated cardiomyopathy (Mazzarotto_2020). The report does not provide unequivocal conclusions about association of the variant with Limb-Girdle Muscular Dystrophy, Autosomal Recessive. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three ClinVar submitters (evaluation after 2014) cite the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
Uncertain significance, no assertion criteria provided	clinical testing	Stanford Center for Inherited Cardiovascular Disease, Stanford University	Mar 27, 2014	Note this variant was found in clinical genetic testing performed by one or more labs who may also submit to ClinVar. Thus any internal case data may overlap with the internal case data of other labs. The interpretation reviewed below is that of the Stanford Center for Inherited Cardiovascular Disease. p.Ile54Val (c.160 A>G) in the SGCD gene (NM_000337.5) Given the lack of case data we consider this variant a variant of uncertain significance. The variant is novel. In silico analysis with PolyPhen-2 predicts the variant to be benign and analysis with SIFT predicts it to be tolerated. However, GeneDx notes in their report that in silico analysis predicts it to be probably damaging (they do not note which program they used). The isoleucine at codon 54 is highly though not completely conserved across species, as are neighboring amino acids. In total the variant has been seen in 1 of 7389 individuals from publicly available population datasets. There is no variation at codon 54 listed in the NHLBI Exome Sequencing Project dataset, which currently includes variant calls on ~6300 Caucasian and African American individuals (as of May 29th, 2014). The variant was observed in 1 of 1089 individuals in the 1000 genomes phase 1 data (as of June 2nd, 2014). This individual was one of the 61 African American subjects. Of note this is low coverage sequencing data which may have false positives. The variant is listed in dbSNP (rs200671745) pointing to the 1000 genomes data (as of June 2nd, 2014). -

Autosomal recessive limb-girdle muscular dystrophy type 2F Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Sep 07, 2022	This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 54 of the SGCD protein (p.Ile54Val). This variant is present in population databases (rs200671745, gnomAD 0.06%). This missense change has been observed in individual(s) with clinical features of dilated cardiomyopathy (PMID: 31983221). ClinVar contains an entry for this variant (Variation ID: 202087). 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Feb 08, 2023	- -

Autosomal recessive limb-girdle muscular dystrophy type 2F;C1847667:Dilated cardiomyopathy 1L Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Nov 08, 2021

- -

Dilated cardiomyopathy 1L Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genome-Nilou Lab

Feb 08, 2023

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.095
BayesDel_addAF	Benign	-0.072	T
BayesDel_noAF	Uncertain	0.030
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.55	.;D;.
Eigen	Uncertain	0.62
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.87	D;D;D
M_CAP	Benign	0.053	D
MetaRNN	Uncertain	0.43	T;T;T
MetaSVM	Uncertain	0.70	D
MutationAssessor	Benign	1.1	.;L;.
PrimateAI	Pathogenic	0.82	D
PROVEAN	Benign	-0.66	N;N;N
REVEL	Pathogenic	0.68
Sift	Benign	0.27	T;T;T
Sift4G	Benign	0.43	T;T;T
Polyphen		0.98	D;P;P
Vest4		0.62
MVP		0.78
MPC		0.28
ClinPred		0.16	T
GERP RS		5.6
Varity_R		0.10
gMVP		0.42

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

LitVar

Other links and lift over

dbSNP: rs200671745; hg19: chr5-155771655;