FCSK

Chr 16AR

fucose kinase

Also known as: 1110046B12Rik, CDGF2, FUK

NCBI Gene: 197258ENSG00000157353UniProt: Q8N0W3

The protein encoded by this gene belongs to the GHMP (galacto-, homoserine, mevalonate and phosphomevalonate) kinase family and catalyzes the phosphorylation of L-fucose to form beta-L-fucose 1-phosphate. This enzyme catalyzes the first step in the utilization of free L-fucose in glycoprotein and glycolipid synthesis. L-fucose may be important in mediating a number of cell-cell interactions such as blood group antigen recognition, inflammation, and metastatis. While several transcript variants may exist for this gene, the full-length nature of only one has been described to date. [provided by RefSeq, Jul 2008]

Primary Disease Associations & Inheritance

Congenital disorder of glycosylation with defective fucosylation 2MIM #618324
AR
78
ClinVar variants
1
Pathogenic / LP
0.00
pLI score
0
Active trials
Clinical Summary— FCSK
🧬
Gene-Disease Validity (ClinGen)
congenital disorder of glycosylation with defective fucosylation 2 · ARLimited

Limited evidence — not for standalone diagnostic reporting

⚡
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
1 Pathogenic / Likely Pathogenic· 53 VUS of 78 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD
Tolerant — LoF & missense variants common in population
LoF Constraint?LOEUF (Loss-of-function Observed/Expected Upper bound Fraction) is the upper bound of the 90% CI for LoF OE — the preferred gnomAD v4 metric. Lower = more intolerant to LoF. LOEUF < 0.35 = highly constrained.
1.13LOEUF
pLI 0.000
Z-score 0.75
OE 0.89 (0.70–1.13)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?Missense Z-score: standard deviations fewer missense variants observed vs. expected. Z > 3.09 (p < 0.001) = gene does not tolerate missense variation. OE missense < 0.6 is also considered constrained.
0.40Z-score
OE missense 0.96 (0.90–1.02)
634 obs / 662.7 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?Shaded band = 90% confidence interval. Vertical tick = point estimate. Grey threshold line = gnomAD constraint cutoff for that variant class.
LoF OE?Ratio of observed to expected LoF variants. Upper CI bound (LOEUF) ≤ 0.35 = strong LoF constraint signal.0.89 (0.70–1.13)
0≤0.351.4
Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.96 (0.90–1.02)
0≤0.61.4
Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.0.99
0≤1.21.6
LoF obs/exp: 48 / 53.9Missense obs/exp: 634 / 662.7Syn Z: 0.16

ClinVar Variant Classifications

78 submitted variants in ClinVar

ClinVar

Classification Summary

Likely Pathogenic1
VUS53
Likely Benign23
Benign1
1
Likely Pathogenic
53
VUS
23
Likely Benign
1
Benign

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
0
0
0
Likely Pathogenic
1
0
0
0
1
VUS
1
52
0
0
53
Likely Benign
0
1
10
12
23
Benign
0
0
1
0
1
Total253111278

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

FCSK · protein map & ClinVar variants

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

Gene2Phenotype Curations

FCSK-related congenital disorder of glycosylation

strong
ARUndeterminedAltered Gene Product Structure
Dev. Disorders
G2P ↗
missense variantinframe deletioninframe insertion

Gene2Phenotype curations · DECIPHER consortium patient cohort (public variants) · deciphergenomics.org

OMIM — Genotype-Phenotype Relationships

1 OMIM entry

OMIM
FUCOSE KINASE; FCSK
MIM #608675 · *

Congenital disorder of glycosylation with defective fucosylation 2

MIM #618324

Molecular basis of disorder known

Autosomal recessive
Clinical Literature
Landmark / reviewRecent case evidence
Key Publications
Landmark & review papers · by relevance
PubMed
Top 10 resultsSearch PubMed ↗
Recent Gene-Specific Literature
Gene in title · MEDLINE · newest first
Europe PMC
Top 5 resultsSearch Europe PMC ↗

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →

External Resources

Links to major genomics databases and tools