CASD1

Chr 7

CAS1 domain sialic acid O acetyltransferase 1

Also known as: C7orf12, Cas1, Cas1p, NBLA04196, SOAT

CASD1 encodes an N-acetylneuraminate 9-O-acetyltransferase that catalyzes the biosynthesis of O-acetylated sialoglycans including gangliosides O-AcGD3 and O-AcGD2, which are critical for cell-cell interactions and neural function. The gene is highly constrained against loss-of-function variants (LOEUF 0.435), suggesting mutations would be deleterious, though no specific human disease phenotype has been established yet. Any associated disorder would likely follow autosomal recessive inheritance given the gene's tolerance to heterozygous loss-of-function.

OMIMResearchSummary from RefSeq, UniProt
DNmechanismLOEUF 0.43
Clinical SummaryCASD1
Population Constraint (gnomAD)
Constrained for loss-of-function variants (OE-LoF 0.26) despite low pLI — interpret in context.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Moderate LoF intolerance
LoF Constraint
0.43LOEUF
pLI 0.045
Z-score 4.42
OE 0.26 (0.160.43)
Moderately constrained

More LoF-intolerant than ~75% of genes

Missense Constraint
1.96Z-score
OE missense 0.73 (0.660.80)
294 obs / 405.3 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.26 (0.160.43)
00.351.4
Missense OE0.73 (0.660.80)
00.61.4
Synonymous OE0.98
01.21.6
LoF obs/exp: 11 / 41.9Missense obs/exp: 294 / 405.3Syn Z: 0.21
DN
0.6550th %ile
GOF
0.5268th %ile
LOF
0.3066th %ile

The highest-scoring mechanism for this gene is dominant-negative.

DNprediction 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.

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

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

CASD1 · 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.

Search ClinicalTrials.gov →
Clinical Literature
Open Research Assistant →
Key Publications
Landmark & review papers · by relevance
PubMed
Top 2 results · since 2015Search PubMed ↗