Is PSAP p.Pro189= (c.567C>G) pathogenic?

PSAP p.Pro189= (c.567C>G) is classified Likely benign in PSAP (ClinVar, Single submitter, 1 submitter; last evaluated 2023-02-03). Very rare (popmax 0.00329%, sas); Associated with metachromatic leukodystrophy due to saposin B deficiency.

What condition is associated with PSAP p.Pro189= (c.567C>G)?

PSAP p.Pro189= (c.567C>G) is associated with metachromatic leukodystrophy due to saposin B deficiency (ClinVar).

How common is PSAP p.Pro189= (c.567C>G) in the general population?

PSAP p.Pro189= (c.567C>G) is very rare (popmax 0.00329%, sas) (gnomAD).

How is Metachromatic leukodystrophy inherited?

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

PSAP p.Pro189=

c.567C>G · rs760310283 · VCV2027880

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.00329%, sas)

Conditions

metachromatic leukodystrophy due to saposin B deficiency

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 0.75	GERP -3.4, phastCons 0.19
Overall
CADD	9.809	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00329% South Asian · 3/91,060 alleles

Filtering AF 0.000875% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.000443%

Overall 0.000186% 3/1,613,996 alleles · very rare exomes 3/1,461,810 · genomes 0/152,186 · joint denominator

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: PSAP
Protein: p.Pro189=
Coding: c.567C>G
MANE Select: NM_002778
dbSNP: rs760310283
Type: single nucleotide variant
Location: chr10:71828886 (GRCh38)
Gene constraint: LOEUF 0.507 · pLI 0.95 (gnomAD)
Structure: AlphaFold pLDDT 73.90 · 21 PDB

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

Disease context

metachromatic leukodystrophy due to saposin B deficiency — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Metachromatic leukodystrophy (Orphanet):

Inheritance: Autosomal recessive
Onset: Adolescent, Adult, Childhood, Infancy
Prevalence: 1-9 / 100 000 (Europe)

Similar variants

PSAP p.Pro189Ser Conflicting classifications of pathogenicity ★ ⚠ same residue
PSAP c.1005+1G>A Pathogenic/Likely pathogenic ★★ same condition
PSAP c.375+1G>T Likely pathogenic ★★ same condition
PSAP c.576+1G>A Likely pathogenic ★★ same condition
PSAP c.577-1G>T Pathogenic ★★ same condition
PSAP c.721-1G>A Likely pathogenic ★★ same condition
PSAP p.Asn215His Pathogenic/Likely pathogenic ★★ same condition
PSAP p.Asn215Lys Pathogenic/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/psap-p-pro189 (accessed [today's date]).

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