FBP2

Chr 9AD

fructose-bisphosphatase 2

This gene encodes fructose-1,6-bisphosphatase 2, a gluconeogenesis regulatory enzyme that catalyzes the hydrolysis of fructose 1,6-bisphosphate to fructose 6-phosphate and inorganic phosphate. Mutations cause childhood-onset remitting leukodystrophy with autosomal dominant inheritance. The gene is highly tolerant to loss-of-function variants, suggesting the pathogenic variants may have other mechanisms of action.

OMIMResearchSummary from RefSeq, OMIM
MultiplemechanismADLOEUF 0.991 OMIM phenotype
Clinical SummaryFBP2
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
Some data sources returned errors (1)

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Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.99LOEUF
pLI 0.000
Z-score 1.59
OE 0.55 (0.320.99)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
0.19Z-score
OE missense 0.96 (0.861.08)
201 obs / 208.7 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.55 (0.320.99)
00.351.4
Missense OE0.96 (0.861.08)
00.61.4
Synonymous OE1.00
01.21.6
LoF obs/exp: 8 / 14.5Missense obs/exp: 201 / 208.7Syn Z: 0.03
DN
0.76top 25%
GOF
0.6541th %ile
LOF
0.2775th %ile

This gene has evidence for multiple mechanisms of pathogenicity (dominant-negative and gain-of-function). Both the Badonyi & Marsh prediction and the broader genomic evidence point to dominant-negative as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

DNprediction above median · 1 literature citation
GOFprediction above median

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Literature Evidence

DNExome sequencing did not-identify any mutations in known leukodystrophy genes but revealed a heterozygous variant in the FBP2 gene, c.343G>A, p. Biochemical analysis showed that the variant has a dominant negative effect on enzymatic activity, substrate affinity, cooperativity and thermal stability.PMID:33977262

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

FBP2 · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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Clinical Literature
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