Is MAN2B1 p.Pro285= (c.855C>G) pathogenic?

MAN2B1 p.Pro285= (c.855C>G) is classified Likely benign in MAN2B1 (ClinVar, Single submitter, 1 submitter; last evaluated 2021-05-10). Very rare (popmax 0.000254%, nfe); Associated with alpha-mannosidosis.

What condition is associated with MAN2B1 p.Pro285= (c.855C>G)?

MAN2B1 p.Pro285= (c.855C>G) is associated with alpha-mannosidosis (ClinVar).

How common is MAN2B1 p.Pro285= (c.855C>G) in the general population?

MAN2B1 p.Pro285= (c.855C>G) is very rare (popmax 0.000254%, nfe) (gnomAD).

How is Alpha-mannosidosis inherited?

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

MAN2B1 p.Pro285=

c.855C>G · rs139218045 · VCV1622199

Likely benign Single submitter

Classification

Likely benign

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

gnomAD v4.1

Rare

very rare (popmax 0.000254%, nfe)

Conditions

alpha-mannosidosis

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 -3.3
Overall
CADD	0.02	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.000254% European (non-Finnish) · 3/1,179,988 alleles

Filtering AF 6.8e-05% ClinGen BA1/BS1 input FAF95, joint · FAF99 1.9e-05%

Overall 0.000186% 3/1,614,062 alleles · very rare exomes 3/1,461,832 · genomes 0/152,230 · 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: MAN2B1
Protein: p.Pro285=
Coding: c.855C>G
MANE Select: NM_000528
dbSNP: rs139218045
Type: single nucleotide variant
Location: chr19:12663371 (GRCh38)
Gene constraint: LOEUF 0.898 · pLI <0.01 (gnomAD)
Structure: AlphaFold pLDDT 91.78
Residue 285: a UniProt-annotated variant site (in mansa)

Full MAN2B1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

alpha-mannosidosis — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

For Alpha-mannosidosis (Orphanet):

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

Similar variants

MAN2B1 c.1026+2T>G Pathogenic/Likely pathogenic ★★ same condition
MAN2B1 c.1109+1G>C Pathogenic/Likely pathogenic ★★ same condition
MAN2B1 c.1527+1G>A Likely pathogenic ★★ same condition
MAN2B1 c.1527+1G>T Pathogenic/Likely pathogenic ★★ same condition
MAN2B1 c.1527+2T>G Pathogenic ★★ same condition
MAN2B1 c.1528-1G>A Pathogenic/Likely pathogenic ★★ same condition
MAN2B1 c.1528-1G>T Likely pathogenic ★★ same condition
MAN2B1 c.159+2T>C 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/man2b1-p-pro285 (accessed [today's date]).

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