Related Experiment Video

Updated: Jun 21, 2026

Reverse Yeast Two-hybrid System to Identify Mammalian Nuclear Receptor Residues that Interact with Ligands and/or Antagonists
10:51

Reverse Yeast Two-hybrid System to Identify Mammalian Nuclear Receptor Residues that Interact with Ligands and/or Antagonists

Published on: November 15, 2013

Cytochrome P450 oxidoreductase deficiency with Antley-Bixler syndrome: steroidogenic capacities

Shigeo Iijima1, Akira Ohishi, Takehiko Ohzeki

  • 1Department of Pediatrics, Hamamatsu University School of Medicine, Japan. sige_pd@yahoo.co.jp

Journal of Pediatric Endocrinology & Metabolism : JPEM
|July 22, 2009
PubMed

Insights

Patients with cytochrome P450 oxidoreductase deficiency (PORD) show altered hormonal stress responses. Steroid replacement needs careful dosing to avoid excess, especially during illness.

Area of Science:

  • Endocrinology
  • Genetics
  • Pediatrics

Background:

  • Cytochrome P450 oxidoreductase deficiency (PORD) necessitates stress-related steroid replacement.
  • Hormonal responses to physical stress in PORD patients remain poorly understood.

Observation:

  • A female infant with PORD and Antley-Bixler syndrome was studied.
  • Urinary steroid profile indicated CYP17A1 and CYP21A2 deficiencies.
  • Adrenocorticotropin (ACTH) stimulation suggested adrenal insufficiency.

Findings:

  • Vigorous crying minimally impacted serum cortisol.
  • Acute viral gastroenteritis caused significant ACTH and 17alpha-hydroxyprogesterone increases.
  • Cortisol response to gastroenteritis appeared blunted.
  • Peri-operative hydrocortisone at 6 mg/kg was excessive.

Implications:

  • PORD patients exhibit unique hormonal stress responses.
  • Current steroid replacement guidelines may require adjustment for PORD.
  • Individualized dosing is crucial for managing PORD patients during stress and surgery.

More Related Videos

Mass Spectrometry and Luminogenic-based Approaches to Characterize Phase I Metabolic Competency of In Vitro Cell Cultures10:44

Mass Spectrometry and Luminogenic-based Approaches to Characterize Phase I Metabolic Competency of In Vitro Cell Cultures

Published on: March 28, 2017

Related Concept Videos

Protein Import into the Peroxisomes01:27

Protein Import into the Peroxisomes

Cells contain membrane-bound organelles called peroxisomes that oxidize organic molecules by transferring hydrogen atoms to oxygen, producing hydrogen peroxide. Peroxisomes enzymatically convert the released hydrogen peroxide into water and oxygen.
Peroxisomal Protein Import:
Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes01:28

Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes

Cytochrome P450 (CYP450) enzymes are a superfamily of heme-containing monooxygenases that play a pivotal role in Phase I drug metabolism by catalyzing oxidation and reduction reactions.These enzymes transform lipophilic xenobiotics into more hydrophilic metabolites, facilitating subsequent Phase II conjugation and eventual excretion. The CYP450 family is classified into families (e.g., CYP1–CYP3) and subfamilies (e.g., CYP2A, CYP2C), based on amino acid sequence homology.CYP450 isoenzymes,...
Smooth Endoplasmic Reticulum01:21

Smooth Endoplasmic Reticulum

Smooth endoplasmic reticulum or smooth ER is a sub-organelle with specialized functions in animal cells and plant cells. It is often associated with the tubule morphology of the endoplasmic reticulum.
The ER provides optimal conditions for synthesizing steroid hormones and lipids, such as phospholipids and triglycerides. Traditionally, lipid metabolism was considered to be a smooth ER function. However, there is no direct evidence to prove that rough ER is completely excluded from lipid...
Adrenal Gland Disorders01:27

Adrenal Gland Disorders

Adrenal gland disorders manifest when the production of adrenal hormones deviates from the norm, resulting in either excessive or insufficient concentrations.
Adrenal insufficiency, characterized by insufficient cortisol and aldosterone production, leads to conditions like Addison's disease. This disorder, affecting the adrenal cortex, exhibits symptoms such as skin bronzing, dehydration, low blood pressure, fatigue, and weight loss. Congenital adrenal hyperplasia, a genetic ailment causing...
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase01:11

Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase

Genetic polymorphisms in drug targets have emerged as critical determinants of interindividual variability in drug response and toxicity. Pharmacogenomic investigations increasingly focus on identifying these variations to personalize and optimize therapeutic interventions. A drug target may be a receptor, enzyme, or signaling protein involved in pharmacologic responses or disease-related pathways. While early pharmacogenetic studies focused primarily on drug metabolism, current research...
Drug Metabolism: Phase I Reactions01:17

Drug Metabolism: Phase I Reactions

A phase I reaction is a biochemical process that introduces a functionally reactive polar group to a substance. This transformation predominantly occurs in the liver, facilitated by the cytochrome P450 system of hemoproteins situated in the lipophilic endoplasmic reticulum of cells. The metabolite generated through this process can have varying polarities. If it is sufficiently polar, it can be easily excreted in the urine due to its water compatibility. However, if the metabolite is nonpolar,...