Related Experiment Videos
Histidinemia: a biochemical variant or a disease?
Journal of the American College of Nutrition
|April 1, 1993
Summary
Histidemia is an inherited metabolic disorder caused by a histidase defect, leading to high histidine levels. While often asymptomatic, it can range from normal to severe retardation, with no clear clinical-biochemical correlation.
Area of Science:
- Biochemistry
- Genetics
- Metabolic Disorders
Background:
- Histidemia, identified in 1961, stems from a deficiency in the enzyme histidase.
- This defect causes elevated histidine levels in blood and urine, with patient levels ranging from 290-1420 microM (normal 70-120 microM).
Purpose of the Study:
- To review the clinical and biochemical characteristics of histidemia.
- To discuss its inheritance, frequency, and management strategies.
Main Methods:
- Literature review of histidemia cases.
- Analysis of clinical and biochemical data from affected individuals.
- Examination of animal model studies.
Main Results:
- Clinical presentation varies widely, from asymptomatic cases to severe intellectual disability, with no consistent correlation between biochemical and clinical findings.
- Identified primarily through newborn screening programs, histidemia frequency varies globally (e.g., 1 in 8000 in Japan, 1 in 37,000 in Sweden).
- Inherited as an autosomal recessive trait, maternal histidemia is considered benign; animal models show metabolic but not clinical similarities.
Conclusions:
- Histidemia management with a low-histidine diet can normalize histidine levels but typically does not improve clinical symptoms.
- The variable clinical presentation and lack of correlation with biochemical data highlight the complexity of histidemia.