Which of the following is almost always a hereditary disease?

Porphyria is a group of diseases in which substances called porphyrins build up, negatively affecting the skin or nervous system. Symptoms of an attack include abdominal pain, chest pain, vomiting, confusion, constipation, fever, high blood pressure, and high heart rate. The attacks usually last for days to weeks. Complications may include paralysis, low blood sodium levels, and seizures.

Most types of porphyria are inherited from one or both of a person's parents, and are due to a mutation in one of the genes that make heme. They may be inherited in an autosomal dominant, autosomal recessive, or X-linked dominant manner. Diagnosis is typically made by blood, urine, and stool tests. Genetic testing may be done to determine the specific mutation.