rs1555568984

Variant names:

• chr17-50169129-A-G
• rs1555568984
• NM_000023.4:c.622A>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PM5

The NM_000023.4(SGCA):​c.622A>G​(p.Thr208Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T208I) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: SGCA NM_000023.4 missense
• Clinical Significance: Uncertain significance no assertion criteria provided U:1
• Conservation: PhyloP100: 0.236
• Publications: 0 publications found

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, STRONG Submitted by: ClinGen, PanelApp Australia
• autosomal recessive limb-girdle muscular dystrophy type 2D

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Myriad Women’s Health, Labcorp Genetics (formerly Invitae), Orphanet

ENSG00000253730 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM1: In a hotspot region, there are 6 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 chr17-50169130-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 285736.

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.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SGCA	NM_000023.4	MANE Select	c.622A>G	p.Thr208Ala	missense	Exon 6 of 10	NP_000014.1	A0A0S2Z4Q1
	SGCA	NM_001135697.3		c.584+557A>G		intron	N/A	NP_001129169.1	A0A0S2Z4P8
	SGCA	NR_135553.2		n.658A>G		non_coding_transcript_exon	Exon 6 of 9

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SGCA	ENST00000262018.8	TSL:1 MANE Select	c.622A>G	p.Thr208Ala	missense	Exon 6 of 10	ENSP00000262018.3	Q16586-1
	SGCA	ENST00000344627.10	TSL:1	c.584+557A>G		intron	N/A	ENSP00000345522.6	Q16586-2
	SGCA	ENST00000952408.1		c.712A>G	p.Thr238Ala	missense	Exon 6 of 10	ENSP00000622467.1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
-	1	-	Autosomal recessive limb-girdle muscular dystrophy type 2D (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.071
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
CADD	Benign	19
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.69	D
Eigen	Benign	-0.37
Eigen_PC	Benign	-0.31
FATHMM_MKL	Benign	0.17	N
LIST_S2	Benign	0.64	T
M_CAP	Uncertain	0.22	D
MetaRNN	Uncertain	0.49	T
MetaSVM	Uncertain	0.33	D
MutationAssessor	Uncertain	2.3	M
PhyloP100		0.24
PrimateAI	Benign	0.41	T
PROVEAN	Benign	-0.68	N
REVEL	Uncertain	0.59
Sift	Uncertain	0.022	D
Sift4G	Benign	0.10	T
Polyphen		0.090	B
Vest4		0.19
MutPred		0.79		Loss of loop (P = 0.0804)
MVP		0.98
MPC		0.38
ClinPred		0.25	T
GERP RS		2.9
Varity_R		0.067
gMVP		0.47
Mutation Taster		=17/83	disease causing

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

Other links and lift over

dbSNP: rs1555568984; hg19: chr17-48246490;