PRG3

Chr 11

proteoglycan 3, pro eosinophil major basic protein 2

Also known as: MBP2, MBPH

NCBI Gene: 10394 ENSG00000156575 UniProt: Q9BRQ8

An extracellular matrix structural constituent conferring compression resistance. Involved in several processes, including granulocyte activation; histamine biosynthetic process; and regulation of gene expression. Located in extracellular matrix. [provided by Alliance of Genome Resources, Jun 2026]

Research

ResearchGenerating clinical summary…

Active trials

Pubs (1 yr)

—

P/LP submissions

—

P/LP missense

1.14

LOEUF

Mechanism· predicted

Some data sources returned errors (1)

omim: Error: OMIM fetch failed: 429

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?

1.14LOEUF

pLI 0.000

Z-score 1.23

OE 0.61 (0.34–1.14)

Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?

-0.45Z-score

OE missense 1.12 (0.97–1.29)

133 obs / 119.1 exp

Tolerant

Tolerant to missense variation

Observed / Expected Ratios?

LoF OE?0.61 (0.34–1.14)

0≤0.351.4

Missense OE?1.12 (0.97–1.29)

0≤0.61.4

Synonymous OE?1.14

0≤1.21.6

LoF obs/exp: 7 / 11.5Missense obs/exp: 133 / 119.1Syn Z: -0.74

Background carrier burden — how many people carry a rare variant somewhere in PRG3?

gnomAD v4 · ~731k individuals · PASS only

Rare means allele frequency under

Rare missense

1 in 220

299 rare PASS variants

Rare truncating (LoF)

1 in 620

62 rare PASS variants

Rare synonymous (reference)

1 in 340

117 rare PASS variants

Rare missense and truncating variants are carried at similar rates in PRG3; this gene does not show strong loss-of-function constraint by this measure. A background rate for each class, not the frequency of any particular variant; thin-coverage exons undercount.

By genetic ancestry · 9 gnomAD groups · rare = under 0.1% in that group

Group	People	Missense	Truncating
European (non-Finnish)	~556k	1 in 300	1 in 2,900
South Asian	~43k	1 in 150	1 in 5,300
Remaining (unassigned)	~30k	1 in 130	1 in 1,300
European (Finnish)	~27k	1 in 450	≈ 1 in 8,700
Admixed American	~22k	1 in 140	1 in 3,200
African / African American	~21k	1 in 170	1 in 470
East Asian	~20k	1 in 180	1 in 4,000
Ashkenazi Jewish	~13k	1 in 2,600	≈ 1 in 3,300
Middle Eastern	~2,884	1 in 190	≈ 1 in 710

Each group is summed over the variants that are rare in that group. Grey ≈ figures rest on fewer than five expected carriers — too few to distinguish groups. Differences mostly reflect how many people were sampled and how much variation each ancestry carries, not disease risk.

Exome coverage (gnomAD): 4 of 5 coding exons well covered in gnomAD exomes; exon 2 marginal. Genomes: all 5.? see exons ↓