FOLH1B

Chr 11

folate hydrolase 1B (pseudogene)

Also known as: FOLH2, FOLHP, PSM, PSMA-LIKE, PSMAL

NCBI Gene: 219595 ENSG00000134612 UniProt: Q9HBA9 OMIM: 609020

The protein functions as a metallocarboxypeptidase with folate hydrolase and N-acetylated-alpha-linked-acidic dipeptidase activities, involved in C-terminal protein deglutamylation. FOLH1B mutations cause autosomal recessive spastic paraplegia, presenting as progressive lower limb spasticity and weakness affecting the motor system.

OMIM ResearchSummary from RefSeq, UniProt

Enables Ac-Asp-Glu binding activity and metallocarboxypeptidase activity. Involved in obsolete glutamate biosynthetic process. Located in extracellular exosome. [provided by Alliance of Genome Resources, Jun 2026]

OMIM ResearchGenerating clinical summary…

Active trials

Pubs (1 yr)

—

P/LP submissions

—

P/LP missense

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LOEUF

Mechanism· predicted

Population Genetics & Constraint

gnomAD

Constraint data not available from gnomAD.

Background carrier burden — how many people carry a rare variant somewhere in FOLH1B?

gnomAD v4 · ~731k individuals · PASS only

Rare means allele frequency under

Rare missense

none observed

0 rare PASS variants

Rare truncating (LoF)

1 in 1,700

28 rare PASS variants

Rare synonymous (reference)

none observed

0 rare PASS variants

Rare missense and truncating variants are carried at similar rates in FOLH1B; 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 · 7 gnomAD groups · rare = under 0.1% in that group

Group	People	Missense	Truncating
European (non-Finnish)	~556k	none seen	1 in 3,300
South Asian	~43k	none seen	1 in 3,200
Remaining (unassigned)	~30k	none seen	1 in 1,100
Admixed American	~22k	none seen	1 in 1,500
African / African American	~21k	none seen	1 in 1,600
East Asian	~20k	none seen	1 in 1,100
Middle Eastern	~2,884	none seen	≈ 1 in 2,600

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.