17-50167695-G-C

Variant names:

• chr17-50167695-G-C
• NM_000023.4:c.271G>C

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PS1_Moderate PM1 PM2 PM5 PP3_Strong PP5

The NM_000023.4(SGCA):​c.271G>C​(p.Gly91Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,166 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 Lovd as Pathogenic (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in UniProt. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G91S) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SGCA NM_000023.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 8.56

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 13 ACMG points.

• PS1: Transcript NM_000023.4 (SGCA) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in UniProt
• PM1: In a topological_domain Extracellular (size 266) in uniprot entity SGCA_HUMAN there are 108 pathogenic changes around while only 2 benign (98%) 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 chr17-50167695-G-A is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994
• PP5: Variant 17-50167695-G-C is Pathogenic according to our data. Variant chr17-50167695-G-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SGCA	NM_000023.4	c.271G>C	p.Gly91Arg	missense_variant	Exon 3 of 10	ENST00000262018.8	NP_000014.1
SGCA	NM_001135697.3	c.271G>C	p.Gly91Arg	missense_variant	Exon 3 of 8		NP_001129169.1
SGCA	NR_135553.2	n.307G>C		non_coding_transcript_exon_variant	Exon 3 of 9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SGCA	ENST00000262018.8	c.271G>C	p.Gly91Arg	missense_variant	Exon 3 of 10	1	NM_000023.4	ENSP00000262018.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461166 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 726820

Gnomad4 AFR exome AF: 0.0000299

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: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	30
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.98	.;D
Eigen	Pathogenic	0.70
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D;D
M_CAP	Pathogenic	0.45	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.5	M;M
PrimateAI	Uncertain	0.60	T
PROVEAN	Pathogenic	-6.3	D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.96
MutPred		0.98		Gain of methylation at G91 (P = 0.0712);Gain of methylation at G91 (P = 0.0712);
MVP		1.0
MPC		1.2
ClinPred		1.0	D
GERP RS		4.5
Varity_R		0.91
gMVP		0.99

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr17-48245056;