Is B9D1 p.Pro142= (c.426C>T) pathogenic?

B9D1 p.Pro142= (c.426C>T) is classified Likely benign in B9D1 (ClinVar, Single submitter, 1 submitter; last evaluated 2023-10-03). Very rare (popmax 0.00549%, sas); Associated with Joubert syndrome.

What condition is associated with B9D1 p.Pro142= (c.426C>T)?

B9D1 p.Pro142= (c.426C>T) is associated with Joubert syndrome, Meckel syndrome (ClinVar).

How common is B9D1 p.Pro142= (c.426C>T) in the general population?

B9D1 p.Pro142= (c.426C>T) is very rare (popmax 0.00549%, sas) (gnomAD).

B9D1 p.Pro142=

c.426C>T · rs775970042 · VCV1935777

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.00549%, sas)

Conditions

Joubert syndrome

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 -9.2	GERP -2.8
Overall
CADD	0.743	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00549% South Asian · 5/91,080 alleles

Filtering AF 0.0021% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00136%

Overall 0.0013% 19/1,461,740 alleles · very rare

Ancestry group	Frequency	1 in
South Asiangrpmax	0.00549%	18,216
Admixed American	0.00167%	60,012
Remaining individualsnot grpmax-eligible	0.0016%	62,494
European (non-Finnish)	0.00102%	98,329

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: B9D1
Protein: p.Pro142=
Coding: c.426C>T
MANE Select: NM_015681
dbSNP: rs775970042
Type: single nucleotide variant
Location: chr17:19343836 (GRCh38)
Gene constraint: LOEUF 1.023 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 83.05

Full B9D1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

Joubert syndrome — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: Meckel syndrome

Similar variants

B9D1 p.Pro142Ser Uncertain significance ★ ⚠ same residue
B9D1 p.Ser142Ter Uncertain significance ★ same residue
B9D1 c.341+2T>C Pathogenic/Likely pathogenic ★★ same condition
B9D1 p.Arg114Gln Pathogenic/Likely pathogenic ★★ ⚠ same condition
B9D1 p.Arg156Trp Pathogenic/Likely pathogenic ★★ same condition
B9D1 c.404+5G>C Uncertain significance ★★ same condition
B9D1 p.Ala44Val Uncertain significance ★★ ⚠ same condition
B9D1 p.Arg101Gln Uncertain significance ★★ 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/b9d1-p-pro142 (accessed [today's date]).

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