ST8SIA3

protein-coding

ST8 alpha-N-acetyl-neuraminide alpha-2,8-sialyltransferase 3, the group of Sialyltransferases

Gene summary

Enables alpha-N-acetylneuraminate alpha-2,8-sialyltransferase activity and identical protein binding activity. Involved in several processes, including N-glycan processing; ganglioside biosynthetic process; and sialylation. Located in Golgi apparatus. [provided by Alliance of Genome Resources, Jun 2026]

Previous symbols:

SIAT8C

MANE transcript

NM_015879.3

Inheritance

—

ClinVar variants

U:37

Top phenotype

—

gnomAD constraint

pLI —, LoF o/e 0.13

Max pathogenic AF

—

Genomic locus

chr18:57,352,557-57,371,731

External References & Databases

Ensembl (ENSG00000177511)

Transcript & Mutation Effects

hg38 • Region Span ~19.2 kb

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GenCC Phenotypes & Disease Associations

Curated gene-disease validity assertions and inheritance patterns

No GenCC data available for this gene.

ClinVar Associated Diseases & Phenotypes

Reported disease conditions connected to ST8SIA3 variants in ClinVar

1 Conditions Cataloged

not specifiedTotal: 37

ClinVar Variants & Pathogenicity by Type

Statistics based on transcript NM_015879.3. Only rare variants are included.

We include only reliable ClinVar variants with their consequences to MANE Select, MANE Plus Clinical transcripts, or transcripts with TSL equal to 1. Click a count to filter the variants table below.

Slight differences between displayed counts and ClinVar may occur due to a different transcript/consequence chosen by our variant effect predictor, or because we classify Benign/Likely benign as Likely benign and Pathogenic/Likely pathogenic as Likely pathogenic.

Effect	PathogenicP	Likely pathogenicLP	VUS	Likely benignLB	BenignB	Sum
synonymous						0
missense			37 clinvar			37
nonsense						0
start loss						0
frameshift						0
splice donor/acceptor (+/-2bp)						0
Total	0	0	37	0	0	37

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Transcript Catalog

Annotated transcript isoforms across RefSeq and Ensembl databases

Showing 4 of 5 transcripts

Transcript ID	Source	Protein ID	Coding Exons	MANE Status
NM_015879.3	RefSeq	NP_056963.2	4	MANE Select
ENST00000324000.4	Ensembl	ENSP00000320431.2	4	MANE Select
ENST00000586360.1	Ensembl	ENSP00000467752.1	2	Standard
ENST00001093718.1	Ensembl	ENSP00000763524.1	3	Standard

Model Organisms & Knockout Phenotypes

Observed phenotypic effects in mouse and zebrafish models

Gene / Model	Organism	Observed Phenotype
st8sia3	Danio rerio	Structure: motor neuron Quality: defasciculated abnormal

Gene / Model

Organism

Observed Phenotype

st8sia3

Danio rerio

Structure: motor neuron

Quality: defasciculated

abnormal

Gene Ontology (GO) Annotations & Pathways

Biological processes, molecular functions, cellular components and pathways

Pathways ConsensusPathDB

Ganglio Sphingolipid Metabolism
Post-translational protein modification
N-Glycan antennae elongation
N-glycan antennae elongation in the medial/trans-Golgi
Metabolism of proteins

Biological Process

ganglioside biosynthetic process
protein glycosylation
N-glycan processing
glycosphingolipid biosynthetic process
glycoprotein metabolic process

Molecular Function

alpha-N-acetylneuraminate alpha-2,8-sialyltransferase activity
sialyltransferase activity
sialic acid binding
identical protein binding

Cellular Component

Golgi membrane
integral component of membrane

gnomAD Constraint

Source: gnomAD

Gene type: protein_coding
Transcript type: protein_coding
Transcript: ENST00000324000
Coding exons: 4
Length: 20919
Individuals with no LoFs: 125738
Homozygous LoFs: 0
Heterozygous LoFs: 8
Defined: 125746
p: 0.0000318

	Z-Score	Observed	Expected	Observed/Expected	Mutation Rate	Total Possible
Missense	1.47	150	210	0.714	0.0000105	2504
Missense (PolyPhen)		35	69.738	0.50188		835
Synonymous	0.173	79	81.0	0.976	0.00000411	724
Loss of Function	3.14	2	15.2	0.132	7.00e-7	187

Population LoF Frequency

Population	CAF	p-value	Status
African	0	0.0	absent
Latino/Admixed American	0.000029	0.000029	rare
Ashkenazi Jewish	0	0.0	absent
East Asian	0	0.0	absent
Finnish	0	0.0	absent
European (Non-Finnish)	0.000035	0.000035	rare
South Asian	0.00016	0.000065	rare
Other	0.00016	0.00016	rare

dbNSFP Gene Annotations

Source: dbNSFP

Function: FUNCTION: Catalyzes the transfer of sialic acid from a CMP-linked sialic acid donor onto the terminal sialic acid of an acceptor through alpha-2,8-linkages. Is active with alpha-2,3-linked, alpha-2,6-linked and alpha-2,8-linked sialic acid of N-linked oligosaccharides of glycoproteins and glycolipids. Displays preference for substrates with alpha-2,3-linked terminal sialic acid. It can form polysialic acid in vitro directly on alpha-2,3-, alpha-2,6-, or alpha-2,8-linked sialic acid. {ECO:0000269|PubMed:10766765, ECO:0000269|PubMed:26192331, ECO:0000269|PubMed:9826427}.;

Recessive Scores

pRec: 0.107

Intolerance Scores

LoFtool: 0.105
RVIS EVS: -0.29
RVIS percentile EVS: 32.94

Essentials

Essential (CRISPR): N
Essential (CRISPR2): N
Essential (gene trap): N
Indispensability pred.: N
Indispensability score: 0.476

Gene Damage Prediction

	All	Recessive	Dominant
Mendelian	Medium	Medium	Medium
Primary Immunodeficiency	Medium	Medium	Medium
Cancer	Medium	Medium	Medium