Is CDC73 p.Arg222Ter (c.664C>T) pathogenic?

CDC73 p.Arg222Ter (c.664C>T) is classified Pathogenic in CDC73 (ClinVar, Multiple submitters, 5 submitters; last evaluated 2026-01-19). Very rare (popmax 0.00223%, eas); Associated with hyperparathyroidism 1.

What condition is associated with CDC73 p.Arg222Ter (c.664C>T)?

CDC73 p.Arg222Ter (c.664C>T) is associated with hyperparathyroidism 1, hyperparathyroidism 2 with jaw tumors, parathyroid gland carcinoma (ClinVar).

How common is CDC73 p.Arg222Ter (c.664C>T) in the general population?

CDC73 p.Arg222Ter (c.664C>T) is very rare (popmax 0.00223%, eas) (gnomAD).

How is Familial isolated hyperparathyroidism inherited?

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

CDC73 p.Arg222Ter

c.664C>T · rs770439843 · VCV658835

Pathogenic Multiple submitters

Classification

Pathogenic

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 5 submitters

Consequence

nonsense (stop-gain)

predicted LoF

gnomAD v4.1

Rare

very rare (popmax 0.00223%, eas)

Conditions

hyperparathyroidism 1

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Consequence	nonsense (stop-gain)	predicted loss-of-function in a haploinsufficient gene (ClinGen)
NMD	predicted	premature termination codon in exon 7 of 17
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 2.5	GERP 1.2, phastCons 0.98
Overall
CADD	36.0	PHRED · no single calibrated threshold — expert panels disagree

Predicted loss-of-function is descriptive, not an applied PVS1 code.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00223% East Asian · 1/44,850 alleles

Filtering AF 2.8e-05% ClinGen BA1/BS1 input FAF95, joint · FAF99 1.1e-05%

Overall 0.000205% 3/1,461,680 alleles · very rare

Ancestry group	Frequency	1 in
East Asiangrpmax	0.00223%	44,850
European (non-Finnish)	0.00017%	589,911

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: CDC73
Protein: p.Arg222Ter
Coding: c.664C>T
MANE Select: NM_024529
dbSNP: rs770439843
Type: single nucleotide variant
Location: chr1:193142001 (GRCh38)
Gene constraint: LOEUF 0.42 · pLI 1.00 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 73.94 · 21 PDB
Residue 222: the 'interaction with polr2a and paf1' region; the 'interaction with ctnnb1' region; an α-helix

Full CDC73 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

hyperparathyroidism 1 — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: hyperparathyroidism 2 with jaw tumors parathyroid gland carcinoma hereditary neoplastic syndrome

For Familial isolated hyperparathyroidism (Orphanet):

Inheritance: Autosomal dominant
Onset: Adult

Similar variants

CDC73 p.Arg222Gln Uncertain significance ★★ ⚠ same residue
CDC73 p.Arg222Gly Uncertain significance ★ ⚠ same residue
CDC73 c.1030+2T>C Likely pathogenic ★★ same condition
CDC73 c.131+1G>A Pathogenic/Likely pathogenic ★★ same condition
CDC73 c.237+1G>A Pathogenic ★★ same condition
CDC73 c.423+1G>A Pathogenic ★★ same condition
CDC73 c.513-1G>A Likely pathogenic ★★ same condition
CDC73 p.Arg120Ter 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/cdc73-p-arg222ter (accessed [today's date]).

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