Is CASR p.Pro22= (c.66A>G) pathogenic?

CASR p.Pro22= (c.66A>G) is classified Likely benign in CASR (ClinVar, Multiple submitters, 2 submitters; last evaluated 2026-02-22). Very rare (popmax 8.47e-05%, nfe); Associated with familial hypocalciuric hypercalcemia.

What condition is associated with CASR p.Pro22= (c.66A>G)?

CASR p.Pro22= (c.66A>G) is associated with familial hypocalciuric hypercalcemia, autosomal dominant hypocalcemia 1 (ClinVar).

How common is CASR p.Pro22= (c.66A>G) in the general population?

CASR p.Pro22= (c.66A>G) is very rare (popmax 8.47e-05%, nfe) (gnomAD).

How is Familial hypocalciuric hypercalcemia inherited?

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

CASR p.Pro22=

c.66A>G · rs2107624825 · VCV1652129

Likely benign Multiple submitters

Classification

Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

gnomAD v4.1

Rare

very rare (popmax 8.47e-05%, nfe)

Conditions

familial hypocalciuric hypercalcemia

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -11	GERP -3.5
Overall
CADD	0.519	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 8.47e-05% European (non-Finnish) · 1/1,180,012 alleles

Overall 6.84e-05% 1/1,461,782 alleles · very rare

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: CASR
Protein: p.Pro22=
Coding: c.66A>G
MANE Select: NM_000388
dbSNP: rs2107624825
Type: single nucleotide variant
Location: chr3:122254255 (GRCh38)
Gene constraint: LOEUF 0.469 · pLI 1.00 (gnomAD)
Structure: AlphaFold pLDDT 76.01 · 31 PDB
Residue 22: the 'ligand-binding 1 (lb1)' region; a β-strand

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

Disease context

familial hypocalciuric hypercalcemia — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: autosomal dominant hypocalcemia 1

For Familial hypocalciuric hypercalcemia (Orphanet):

Inheritance: Autosomal dominant
Onset: All ages

Similar variants

CASR p.Pro22Ser Uncertain significance ★ ⚠ same residue
CASR p.Pro22Thr Uncertain significance ★ ⚠ same residue
CASR c.1378-1G>C Likely pathogenic ★★ same condition
CASR c.1608+1G>A Likely pathogenic ★★ same condition
CASR c.1609-2A>G Likely pathogenic ★★ same condition
CASR c.186-1G>T Pathogenic ★★ same condition
CASR c.493-2A>C Likely pathogenic ★★ same condition
CASR p.Ala581Val 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/casr-p-pro22 (accessed [today's date]).

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