Related Experiment Video
Updated: Sep 8, 2025
09:28
One-step Metabolomics: Carbohydrates, Organic and Amino Acids Quantified in a Single Procedure
Published on: June 25, 2010
13.3K
Inborn Errors of Metabolism: Refsum Disease.
Sitara Hirji1, Stephen Tsang2, Tarun Sharma1
1Department of Ophthalmology, Columbia University, New York, NY, USA.
Advances in Experimental Medicine and Biology
|July 30, 2025
Summary
This study explains Refsum disease, an autosomal recessive disorder. It is caused by a deficiency in phytanic acid oxidation, leading to harmful accumulation in the body.
Area of Science:
- Biochemistry
- Genetics
- Metabolic Disorders
Background:
- Refsum disease is a rare genetic disorder affecting peroxisomal function.
- Phytanic acid accumulation is a hallmark of this condition.
- Understanding the biochemical pathway is crucial for diagnosis and management.
Purpose of the Study:
- To elucidate the biochemical basis of Refsum disease.
- To investigate the consequences of impaired phytanic acid oxidation.
- To highlight the role of peroxisomal enzymes in metabolic health.
Main Methods:
- Analysis of phytanic acid levels in patient plasma.
- Enzyme activity assays for phytanic acid alpha-hydroxylase.
- Genetic analysis to identify mutations in the PEX7 gene.
Main Results:
- Demonstrated deficiency in phytanic acid oxidation.
- Confirmed elevated phytanic acid levels in affected individuals.
- Identified specific genetic mutations responsible for the enzyme defect.
Conclusions:
- Autosomal recessive inheritance pattern confirmed.
- Phytanic acid accumulation directly results from impaired oxidation.
- This deficiency underlies the pathophysiology of Refsum disease.
More Related Videos
Related Concept Videos
01:20Inborn Errors of Metabolism
239
Phenylketonuria (PKU) is a protein metabolism disorder characterized by high blood levels of the amino acid phenylalanine. This results from a mutation in the gene responsible for phenylalanine hydroxylase, an enzyme that converts phenylalanine into tyrosine. When this enzyme is deficient, phenylalanine builds up in the blood, leading to symptoms such as vomiting, rashes, seizures, growth deficiency, and severe mental retardation. An early diagnosis and a diet restricting phenylalanine intake...
239
01:27Protein Import into the Peroxisomes
3.6K
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...
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...
3.6K
01:21Overview of Protein Metabolism
1.8K
Proteins are broken down into amino acids during digestion. Unlike fats and carbohydrates, which are stored for later use, proteins are not. Instead, amino acids are either used to produce ATP through oxidation or contribute to the creation of new proteins for the growth and repair of the body. Any surplus amino acids from the diet are converted into glucose or triglycerides rather than excreted.
Amino acids play various roles in the body once they are absorbed into cells. They are restructured...
Amino acids play various roles in the body once they are absorbed into cells. They are restructured...
1.8K
01:21Smooth Endoplasmic Reticulum
6.2K
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...
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...
6.2K
01:31Translation
15.5K
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of Life
Proteins are...
Translation Produces the Building Blocks of Life
Proteins are...
15.5K
01:19Overview of Carbohydrate Metabolism
1.7K
Carbohydrate metabolism is a fundamental biochemical process that ensures a constant supply of energy to living cells. The most important carbohydrate is glucose, which can be broken down via glycolysis to enter into the Krebs cycle and eventually lead to the production of ATP through oxidative phosphorylation.
Glucose transport into cells is facilitated by a family of transport proteins called GLUT (Glucose Transporters). GLUT4 is the primary glucose transporter for insulin-stimulated glucose...
Glucose transport into cells is facilitated by a family of transport proteins called GLUT (Glucose Transporters). GLUT4 is the primary glucose transporter for insulin-stimulated glucose...
1.7K