rs475992

chr13-23300011-A-G

Variant summary

Our verdict is Benign. Variant got -13 ACMG points: 0P and 13B. BP4_Strong BP6 BA1

The NM_000231.3(SGCG):c.578+4524A>G variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.558 in 152,054 control chromosomes in the GnomAD database, including 24,669 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in Lovd as Benign (no stars).

• Frequency: Genomes: 𝑓 0.56 (24669 hom., cov: 32)
• Consequence: SGCG NM_000231.3 intron
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.01

Genes affected

SGCG (HGNC:10809): (sarcoglycan gamma) This gene encodes gamma-sarcoglycan, one of several sarcolemmal transmembrane glycoproteins that interact with dystrophin. The dystrophin-glycoprotein complex (DGC) spans the sarcolemma and is comprised of dystrophin, syntrophin, alpha- and beta-dystroglycans and sarcoglycans. The DGC provides a structural link between the subsarcolemmal cytoskeleton and the extracellular matrix of muscle cells. Defects in the encoded protein can lead to early onset autosomal recessive muscular dystrophy, in particular limb-girdle muscular dystrophy, type 2C (LGMD2C). [provided by RefSeq, Oct 2008]

SACS (HGNC:10519): (sacsin molecular chaperone) This gene encodes the sacsin protein, which includes a UbL domain at the N-terminus, a DnaJ domain, and a HEPN domain at the C-terminus. The gene is highly expressed in the central nervous system, also found in skin, skeletal muscles and at low levels in the pancreas. This gene includes a very large exon spanning more than 12.8 kb. Mutations in this gene result in autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS), a neurodegenerative disorder characterized by early-onset cerebellar ataxia with spasticity and peripheral neuropathy. The authors of a publication on the effects of siRNA-mediated sacsin knockdown concluded that sacsin protects against mutant ataxin-1 and suggest that "the large multi-domain sacsin protein is able to recruit Hsp70 chaperone action and has the potential to regulate the effects of other ataxia proteins" (Parfitt et al., PubMed: 19208651). A pseudogene associated with this gene is located on chromosome 11. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, May 2013]

ACMG classification

Verdict is Benign. Variant got -13 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.85).
• BP6: Variant 13-23300011-A-G is Benign according to our data. Variant chr13-23300011-A-G is described in Lovd as [Benign].
• BA1: GnomAd4 highest subpopulation (EAS) allele frequency at 95% confidence interval = 0.824 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SGCG	NM_000231.3	c.578+4524A>G		intron_variant		ENST00000218867.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SGCG	ENST00000218867.4	c.578+4524A>G		intron_variant		1	NM_000231.3	P1
SACS	ENST00000683210.1	c.2186-10768T>C		intron_variant

Frequencies

GnomAD3 genomes AF: 0.558 AC: 84752 AN: 151936 Hom.: 24663 Cov.: 32

Gnomad AFR AF: 0.394

Gnomad AMI AF: 0.633

Gnomad AMR AF: 0.667

Gnomad ASJ AF: 0.495

Gnomad EAS AF: 0.844

Gnomad SAS AF: 0.568

Gnomad FIN AF: 0.614

Gnomad MID AF: 0.669

Gnomad NFE AF: 0.603

Gnomad OTH AF: 0.587

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome AF: 0.558 AC: 84786 AN: 152054 Hom.: 24669 Cov.: 32 AF XY: 0.561 AC XY: 41707 AN XY: 74310

Gnomad4 AFR AF: 0.393

Gnomad4 AMR AF: 0.667

Gnomad4 ASJ AF: 0.495

Gnomad4 EAS AF: 0.845

Gnomad4 SAS AF: 0.567

Gnomad4 FIN AF: 0.614

Gnomad4 NFE AF: 0.603

Gnomad4 OTH AF: 0.591

Alfa AF: 0.596 Hom.: 54230

Bravo AF: 0.559

Asia WGS AF: 0.708 AC: 2464 AN: 3478

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.85
Cadd	Benign	7.5
Dann	Benign	0.79

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: rs475992; hg19: chr13-23874150;