HSD3B2 Gene
Hydroxy-Delta-5-Steroid Dehydrogenase, 3 Beta- and Steroid Delta-Isomerase 2
Gene Information Card
| Symbol | HSD3B2 |
|---|---|
| Full Name | Hydroxy-Delta-5-Steroid Dehydrogenase, 3 Beta- and Steroid Delta-Isomerase 2 |
| Gene Type | Protein coding |
| Chromosomal Location | 1p12 |
| NCBI Gene ID | 3284 ncbi.nlm.nih.gov/gene/3284 |
| Ensembl ID | ENSG00000164266 |
| UniProt ID | P26439 |
| OMIM ID | 201810 |
| HGNC ID | 5218 |
| Aliases | 3β-HSD II, HSD3B, SDR11E2 |
Description
The HSD3B2 gene encodes the type 2 isoform of 3β-hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase, a key enzyme in steroidogenesis. This enzyme catalyzes the conversion of Δ5-3β-hydroxysteroids (e.g., pregnenolone, 17α-hydroxypregnenolone, dehydroepiandrosterone) to Δ4-3-ketosteroids (progesterone, 17α-hydroxyprogesterone, androstenedione) in the adrenal cortex and gonads. Mutations in HSD3B2 cause classic 3β-hydroxysteroid dehydrogenase deficiency, a form of congenital adrenal hyperplasia (CAH) characterized by impaired cortisol, aldosterone, and sex steroid synthesis.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| 3β-Hydroxysteroid Dehydrogenase Deficiency (Classic CAH) | Loss-of-function mutations impair conversion of Δ5 to Δ4 steroids, leading to cortisol and aldosterone deficiency with androgen excess in utero. | OMIM #201810; ClinVar pathogenic variants |
| Adrenal Insufficiency (Primary) | Enzyme deficiency reduces cortisol production, triggering ACTH-driven adrenal hyperplasia. | NCBI Gene; OMIM |
| Disorders of Sex Development (46,XY DSD) | Impaired testosterone synthesis in males leads to undervirilization. | OMIM; ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Adrenal Gland | 12.5 | High |
| Testis | 8.3 | Medium |
| Ovary | 6.1 | Medium |
| Placenta | 4.2 | Low |
| Prostate | 1.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| NCI-H295R (Adrenocortical) | 15.2 | High expression; model for steroidogenesis |
| LNCaP (Prostate cancer) | 2.1 | Low expression |
| KGN (Granulosa cell) | 5.4 | Moderate expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.35G>A (p.Trp12Ter) | Nonsense | Rare | Loss of function; truncation |
| c.424G>A (p.Gly142Arg) | Missense | Common in CAH | Impaired enzyme activity |
| c.745C>T (p.Arg249Ter) | Nonsense | Rare | Loss of function; premature stop |
| c.1000C>T (p.Arg334Cys) | Missense | Reported | Reduced catalytic efficiency |
Mutation functional classification
Loss of Function (LOF)
Most HSD3B2 mutations are loss-of-function, reducing or abolishing 3β-HSD activity, leading to classic CAH.
Gain of Function (GOF)
No gain-of-function mutations reported in HSD3B2.
Dominant Negative (DN)
No dominant-negative effects documented; inheritance is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • 3-beta-hydroxy-delta5-steroid dehydrogenase activity (GO:0003854) | • steroid delta-isomerase activity (GO:0004769) |
| • steroid biosynthetic process (GO:0006694) | • C21-steroid hormone biosynthetic process (GO:0032346) |
| • androgen biosynthetic process (GO:0006702) |
Pathways
• Steroidogenesis (Reactome: R-HSA-196108)
• Metabolism of steroids (Reactome: R-HSA-8957322)
• C21-Steroid hormone metabolism (KEGG: hsa00140)
Protein Summary
The HSD3B2 protein (371 amino acids) is a membrane-bound enzyme localized to the endoplasmic reticulum and mitochondria. It belongs to the short-chain dehydrogenase/reductase (SDR) family and functions as a homodimer. The enzyme is essential for the biosynthesis of all classes of steroid hormones: glucocorticoids, mineralocorticoids, and sex steroids. Deficiency leads to accumulation of Δ5 precursors and decreased Δ4 steroids.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| HSD3B2 Knockout HEK293 Cell Line | EDJ-KQ4948 | Human | 3284 | Details Get a Quote |
| HSD3B2 Knockout HeLa Cell Line | EDJ-KQ53575 | Human | 3284 | Details Get a Quote |
| HSD3B2 Knockout A-549 Cell Line | EDJ-KQ62041 | Human | 3284 | Details Get a Quote |
| HSD3B2 Knockout HCT 116 Cell Line | EDJ-KQ70523 | Human | 3284 | Details Get a Quote |
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