Is SGCA p.His63= (c.189C>T) pathogenic?

SGCA p.His63= (c.189C>T) is classified Conflicting classifications of pathogenicity in SGCA (ClinVar, Conflicting submitters, 4 submitters; last evaluated 2026-01-20). Ultra-rare (popmax 0.0653%, afr); Associated with autosomal recessive limb-girdle muscular dystrophy type 2D.

What condition is associated with SGCA p.His63= (c.189C>T)?

SGCA p.His63= (c.189C>T) is associated with autosomal recessive limb-girdle muscular dystrophy type 2D (ClinVar).

How common is SGCA p.His63= (c.189C>T) in the general population?

SGCA p.His63= (c.189C>T) is ultra-rare (popmax 0.0653%, afr) (gnomAD).

SGCA p.His63=

Q: How is Alpha-sarcoglycan-related limb-girdle muscular dystrophy R3 inherited?

Typically Autosomal recessive (Orphanet). A genetic counselor can assess individual risk for a family.

c.189C>T · rs373770886 · VCV497842

Conflicting classifications of pathogenicity Conflicting submitters

Classification

Conflicting classifications of pathogenicity

ClinVar

Review

Conflicting submitters ★☆☆☆

ClinVar · 4 submitters

gnomAD v4.1

Rare

ultra-rare (popmax 0.0653%, afr)

Conditions

autosomal recessive limb-girdle muscular dystrophy type 2D

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	<0.2	no splice effect predicted · four deltas, not one · how we know
Constraint at this position
Conservation	phyloP -12	GERP -2.5
Overall
CADD	7.412	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0653% African / African-American · 49/75,030 alleles

Filtering AF 0.0507% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0455%

Overall 0.00477% 77/1,613,750 alleles · ultra-rare exomes 35/1,461,450 · genomes 42/152,300 · joint denominator

Ancestry group	Frequency	1 in
African / African-Americangrpmax	0.0653%	1,531
Admixed American	0.025%	4,002
Remaining individualsnot grpmax-eligible	0.0032%	31,252
East Asian	0.00223%	44,884
South Asian	0.0011%	91,090
European (non-Finnish)	0.000763%	131,113

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: SGCA
Protein: p.His63=
Coding: c.189C>T
MANE Select: NM_000023
dbSNP: rs373770886
Type: single nucleotide variant
Location: chr17:50167613 (GRCh38)
Gene constraint: LOEUF 1.273 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 80.15

Full SGCA gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

autosomal recessive limb-girdle muscular dystrophy type 2D — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Alpha-sarcoglycan-related limb-girdle muscular dystrophy R3 (Orphanet):

Inheritance: Autosomal recessive
Onset: Adolescent, Childhood
Prevalence: <1 / 1 000 000 (United Kingdom)

Similar variants

SGCA p.His63Tyr Uncertain significance ★ ⚠ same residue
SGCA c.37+6T>C Pathogenic ★★★ same condition
SGCA c.585-1G>A Pathogenic ★★★ same condition
SGCA c.957-11C>G Likely pathogenic ★★★ same condition
SGCA p.Ala107Val Likely pathogenic ★★★ ⚠ same condition
SGCA p.Arg192Ter Pathogenic ★★★ same condition
SGCA p.Arg221Cys Likely pathogenic ★★★ same condition
SGCA p.Arg221Pro Likely pathogenic ★★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/sgca-p-his63 (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown