Inborn errors of steroid metabolism

An inborn error of steroid metabolism is an inborn error of metabolism due to defects in steroid metabolism.^{[citation needed]}

Inborn error of steroid metabolism
Steroidogenesis
Specialty	Medical genetics, endocrinology

Types

A variety of conditions of abnormal steroidogenesis exist due to genetic mutations in the steroidogenic enzymes involved in the process, of which include:

Generalized

• 20,22-Desmolase (P450scc) deficiency: blocks production of all steroid hormones from cholesterol ^{[citation needed]}
• 3β-Hydroxysteroid dehydrogenase 2 deficiency: impairs progestogen and androgen metabolism; prevents the synthesis of estrogens, glucocorticoids, and mineralocorticoids; causes androgen deficiency in males and androgen excess in females^{[citation needed]}
• Combined 17α-hydroxylase/17,20-lyase deficiency: impairs progestogen metabolism; prevents androgen, estrogen, and glucocorticoid synthesis; causes mineralocorticoid excess^{[citation needed]}
• Cytochrome P450 oxidoreductase deficiency: prevents production of numerous but not all sex steroids,^[1] as well as other metabolic reactions

Androgen- and estrogen-specific

• Isolated 17,20-lyase deficiency: prevents androgen and estrogen synthesis.^[2]
  • Cytochrome b₅ deficiency: subtype of isolated 17,20-lyase deficiency; additionally results in elevated methemoglobin and/or methemoglobinemia
• 17β-Hydroxysteroid dehydrogenase 3 deficiency: impairs androgen and estrogen metabolism; results in androgen deficiency in males and androgen excess and estrogen deficiency in females^{[citation needed]}
• 5α-Reductase 2 deficiency: prevents the conversion of testosterone to dihydrotestosterone; causes androgen deficiency in males^{[citation needed]}
• Aromatase deficiency: prevents estrogen synthesis; causes androgen excess in females^{[citation needed]}
• Aromatase excess: causes excessive conversion of androgens to estrogens; results in estrogen excess in both sexes and androgen deficiency in males.^{[citation needed]}

Glucocorticoid- and mineralocorticoid-specific

• 21-Hydroxylase deficiency: prevents glucocorticoid and mineralocorticoid synthesis; causes androgen excess in females^{[citation needed]}
• 11β-Hydroxylase 1 deficiency: impairs glucocorticoid and mineralocorticoid metabolism; causes glucocorticoid deficiency and mineralocorticoid excess as well as androgen excess in females^{[citation needed]}
• 11β-Hydroxylase 2 deficiency: impairs corticosteroid metabolism; results in excessive mineralocorticoid activity^{[citation needed]}
• 18-Hydroxylase deficiency: prevents mineralocorticoid synthesis; results in mineralocorticoid deficiency^{[citation needed]}
• 18-Hydroxylase overactivity: impairs mineralocorticoid metabolism; results in mineralocorticoid excess^{[citation needed]}

Miscellaneous

In addition, several conditions of abnormal steroidogenesis due to genetic mutations in receptors, as opposed to enzymes, also exist, including:^{[citation needed]}

• Gonadotropin-releasing hormone (GnRH) insensitivity: prevents synthesis of sex steroids by the gonads in both sexes
• Follicle-stimulating (FSH) hormone insensitivity: prevents synthesis of sex steroids by the gonads in females; merely causes problems with fertility in males
• Luteinizing hormone (LH) insensitivity: prevents synthesis of sex steroids by the gonads in males; merely causes problems with fertility in females
• Luteinizing hormone (LH) oversensitivity: causes androgen excess in males, resulting in precocious puberty; females are asymptomatic

No activating mutations of the GnRH receptor in humans have been described in the medical literature,^[3] and only one of the FSH receptor has been described, which presented as asymptomatic.^[4][5]

See also

• Inborn error of metabolism
• Disorders of sex development
• Congenital adrenal hyperplasia
• Adrenal insufficiency
• Hypogonadism (hypoandrogenism and hypoestrogenism)
• Hypergonadism (hyperandrogenism and hyperestrogenism)
• Delayed puberty and precocious puberty
• Intersex
• Steroid hormone
• Corticosteroid (glucocorticoid, mineralocorticoid)
• Sex steroid (androgen, estrogen, and progestogen)
• Neuroactive steroid
• Hypothalamus and pituitary gland
• Adrenal cortex and gonad (testicle and ovary)
• HPA axis and HPG axis