Gunther disease

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Obesity, Sleep & Internal medicine
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Gunther disease
Congenital erythropoietic porphyria
Synonyms	Congenital erythropoietic porphyria (CEP)
Pronounce
Specialty	Hematology
Symptoms	Photosensitivity, hemolytic anemia, red urine
Complications	N/A
Onset	Birth or early infancy
Duration	Lifelong
Types	N/A
Causes	Genetic mutation in the UROS gene
Risks
Diagnosis	Urine test, genetic testing
Differential diagnosis	Erythropoietic protoporphyria, Porphyria cutanea tarda
Prevention	Avoidance of sunlight
Treatment	Blood transfusion, bone marrow transplant
Medication
Prognosis	Variable, can be severe
Frequency	Rare
Deaths

Gunther disease, also known as congenital erythropoietic porphyria (CEP), is a rare autosomal recessive metabolic disorder that affects the heme biosynthesis pathway. It is characterized by a deficiency in the enzyme uroporphyrinogen III synthase (UROS), leading to the accumulation of porphyrins in the body.

Signs and Symptoms

Individuals with Gunther disease typically present with severe photosensitivity, leading to blistering and scarring of the skin upon exposure to sunlight. Other symptoms may include:

• Hemolytic anemia
• Splenomegaly
• Hypertrichosis
• Erythrodontia (red discoloration of the teeth)
• Bone fragility

Pathophysiology

Gunther disease is caused by mutations in the UROS gene, which encodes the enzyme uroporphyrinogen III synthase. This enzyme is crucial for the conversion of hydroxymethylbilane to uroporphyrinogen III, a precursor in the heme biosynthesis pathway. Deficiency in UROS leads to the accumulation of non-physiological porphyrins, which are photosensitizing and cause cellular damage upon exposure to light.

Diagnosis

Diagnosis of Gunther disease is based on clinical presentation, family history, and laboratory tests. Key diagnostic tests include:

• Measurement of porphyrin levels in blood, urine, and feces
• Genetic testing for mutations in the UROS gene
• Bone marrow examination to assess erythropoiesis

Treatment

There is no cure for Gunther disease, and treatment is primarily supportive. Management strategies include:

• Avoidance of sunlight and use of protective clothing and sunscreen
• Blood transfusions to manage anemia
• Splenectomy in cases of severe splenomegaly
• Bone marrow transplantation in severe cases

Prognosis

The prognosis for individuals with Gunther disease varies depending on the severity of the condition. Early diagnosis and management can improve the quality of life and reduce complications.

See also

• Porphyria
• Heme
• Autosomal recessive
• Metabolic disorder
• Photosensitivity
• Hemolytic anemia