CYP19A1
cytochrome P450 family 19 subfamily A member 1
Gene summary
A protein-coding gene on chromosome 15 (steroid hormone synthesis). Encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids.
Source: NCBI Gene, accessed 2026-10-07.
Protein reference (UniProt)
- Protein
Aromatase
- Function (excerpt)
A cytochrome P450 monooxygenase that catalyzes the conversion of C19 androgens, androst-4-ene-3,17-dione (androstenedione) and testosterone to the C18 estrogens, estrone and estradiol, respectively. Catalyzes three successive oxidations of C19 androgens: two conventional oxidations at C19 yielding 19-hydroxy and 19-oxo/19-aldehyde derivatives, followed by a third oxidative aromatization step that involves C1-beta hydrogen abstraction combined with cleavage of the C10-C19 bond to yield a phenolic A ring and formic acid. Alternatively, the third oxidative reaction yields a 19-norsteroid and formic acid. Converts dihydrotestosterone to delta1,10-dehydro 19-nordihydrotestosterone and may play a role in homeostasis of this potent androgen. Also displays 2-hydroxylase activity toward estrone.
- Pathway
Steroid hormone biosynthesis.
- Subcellular location
Endoplasmic reticulum membrane; Microsome membrane.
- Tissue specificity
Widely expressed, including in adult and fetal brain, placenta, skin fibroblasts, adipose tissue and gonads.
- Associated conditions
Aromatase excess syndrome (AEXS); Aromatase deficiency (AROD).
Source: UniProtKB/Swiss-Prot P11511, release 2026_03, licensed CC BY 4.0. This is the protein’s normal biology, not evidence about post-drug syndromes; associated conditions are inherited disorders of the gene, not PFS, PSSD or PRSD.
Why its pathway is in the library
Steroid-synthesis enzymes sit directly on the pathways perturbed by 5-alpha-reductase inhibitors and SSRIs; inherited variation here is a candidate susceptibility factor for persistent post-drug phenotypes.
Written for the whole steroid synthesis family, not for CYP19A1 specifically.
Narrative library record
Function
Aromatase - the P450 enzyme catalyzing the final steps of estrogen biosynthesis, converting androgens (testosterone, androstenedione) to estrogens (estradiol, estrone). Tissue-specific promoters drive expression in placenta, gonads, adipose, and brain; variants alter aromatase activity with broad endocrine effects.
Corpus relevance
Background-pathway gene: aromatization is the alternative fate of testosterone besides 5-alpha-reduction to DHT, so CYP19A1 activity shapes the androgen/estrogen balance Powers and the papers discuss (for example, elevated estradiol in PFS CSF, PFS-004; estradiol management in Powers' clinical commentary). No direct PFS/PSSD implication in the corpus.
Mentioned in 4 corpus records
- Gene recordPowers’ theory
AKR1C3 — aldo-keto reductase family 1 member C3
10p15-p14 (AKR1C gene cluster, chromosome 10)
3-alpha-hydroxysteroid dehydrogenase type 2 (also 17-beta-hydroxysteroid dehydrogenase type 5); metabolizes prostaglandins, estrogens, and progesterone in addition to androgens, and is overexpressed in prostate cancer. Broadest substrate range of the four…
AKR1C1AKR1C2AKR1C3AKR1C4CYP19A1GENE-AKR1C3Core corpus - Gene record
The adrenal/gonadal isoform of 3-beta-HSD, predominantly expressed in adrenals, ovaries, and testes; catalyzes the same essential delta-5-to-delta-4 steroid conversion. Deficiency causes a rare congenital adrenal hyperplasia.
CYP17A1CYP19A1HSD3B1HSD3B2SRD5A2GENE-HSD3B2PFSPSSDCore corpus - Gene record
Dual-function P450 enzyme with 17-alpha-hydroxylase and 17,20-lyase activities - the key branch point of steroidogenesis that diverts pregnenolone/progesterone toward glucocorticoids versus DHEA and androstenedione (androgen precursors). Expressed in…
ARCYP17A1CYP19A1HSD3B2SRD5A1GENE-CYP17A1PFSPSSDCore corpus - Gene recordPowers’ theory
Short-chain dehydrogenase/reductase (17-beta-HSD type 2) that inactivates sex steroids, oxidizing testosterone to androstenedione, estradiol to estrone, and androstenediol to DHEA; described as the key 17-beta-HSD isozyme in androgen and estrogen…
AKR1C2CYP17A1CYP19A1HSD17B2SRD5A2+1GENE-HSD17B2PFSCore corpus
Also in steroid hormone synthesis
All 38 genes- SRD5A2
steroid 5 alpha-reductase 2
chr 2· Steroid synthesis· 19 records - SRD5A1Powers
steroid 5 alpha-reductase 1
chr 5· Steroid synthesis· 17 records - AKR1C2Powers
aldo-keto reductase family 1 member C2
chr 10· Steroid synthesis· 12 records - AKR1C3Powers
aldo-keto reductase family 1 member C3
chr 10· Steroid synthesis· 9 records - CYP17A1
cytochrome P450 family 17 subfamily A member 1
chr 10· Steroid synthesis· 9 records - AKR1C4Powers
aldo-keto reductase family 1 member C4
chr 10· Steroid synthesis· 8 records - AKR1C1Powers
aldo-keto reductase family 1 member C1
chr 10· Steroid synthesis· 7 records - HSD3B2
hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 2
chr 1· Steroid synthesis· 7 records
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