Related Experiment Videos
Homozygous variegate porphyria: a case report
P G Norris1, G H Elder, J L Hawk
1Institute of Dermatology, St. Thomas' Hospital, London.
The British Journal of Dermatology
|February 1, 1990
Summary
Homozygous variegate porphyria presents uniquely in a girl with photosensitivity and intellectual disability. Reduced enzyme activity in parents suggests a complex genetic inheritance pattern for this rare hepatic porphyria.
Area of Science:
- Biochemistry
- Genetics
- Clinical Medicine
Background:
- Variegate porphyria (VP) is a rare autosomal dominant disorder.
- Homozygous VP is exceptionally rare, often presenting with severe symptoms.
- Understanding the biochemical and genetic basis is crucial for diagnosis and management.
Observation:
- A 14-year-old female presented with photosensitivity, mental retardation, and clinodactyly.
- Elevated erythrocyte protoporphyrin, predominantly zinc-chelated, was observed.
- Reduced protoporphyrinogen oxidase activity was detected in patient and parental lymphoblasts.
Findings:
- The patient exhibited a unique clinical phenotype for homozygous variegate porphyria.
- Zinc-chelated protoporphyrin in erythrocytes is a potential marker for homozygous hepatic porphyrias.
- Decreased protoporphyrinogen oxidase activity in parents indicates carrier status or a novel inheritance pattern.
Implications:
- This case expands the known clinical spectrum of homozygous variegate porphyria.
- The biochemical findings may aid in diagnosing other homozygous hepatic porphyrias.
- Further research into the genetic transmission and enzyme activity in parents is warranted.