rs1057517377

Positions:

• chr17-50170148-TAA-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000023.4(SGCA):​c.754_755del​(p.Lys252ValfsTer8) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,708 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SGCA NM_000023.4 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 2.24

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-50170148-TAA-T is Pathogenic according to our data. Variant chr17-50170148-TAA-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 371575.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-50170148-TAA-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SGCA	NM_000023.4	c.754_755del	p.Lys252ValfsTer8	frameshift_variant	7/10	ENST00000262018.8
SGCA	NM_001135697.3	c.585-491_585-490del		intron_variant
SGCA	NR_135553.2	n.784-491_784-490del		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SGCA	ENST00000262018.8	c.754_755del	p.Lys252ValfsTer8	frameshift_variant	7/10	1	NM_000023.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461708 Hom.: 0 AF XY: 0.00000275 AC XY: 2 AN XY: 727160

Gnomad4 AFR exome AF: 0.00

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Autosomal recessive limb-girdle muscular dystrophy type 2D Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Aug 15, 2023	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Oct 20, 2016	- -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Oct 19, 2022	- -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs1057517377; hg19: chr17-48247509;