Acute Porphyrias Panel

Test Description:

Three of the porphyrias (AIP, HCP & VP) are associated with acute attacks and similar symptoms and may be grouped together as "Acute Porphyrias". They are each due to a deficiency of a specific enzyme, hydroxymethylbilane synthase, coproporphyrinogen oxidase, and protporphyrinogen oxidase, respectively, due to a mutation, or change in a specific gene. All are autosomal dominant. The enzyme deficiency alone is not sufficient to produce the symptoms of AIP, HCP, or VP and other activating factors, such as drugs, hormones, and dietary changes must be present. Sometimes activating factors cannot be identified. Most people who have a mutation in the gene for AIP, HCP, and VP never develop symptoms; this is referred to as "latent" AIP, HCP, or VP. Symptoms may develop after puberty, especially in women. Unlike AIP, symptoms of HCP and VP may also include photosensitivity.

Acute attacks almost always start with severe pain in the abdomen but sometimes in the chest, back, or thighs, and are often accompanied by nausea, vomiting, and constipation. Heart rate and blood pressure are commonly increased. These symptoms and signs are all due to the effects of the disease on the nervous system. Confusion, convulsions, and muscular weakness, due to impairment of the nerves controlling the muscles, may lead to paralysis. An acute attack usually lasts for days or weeks. Recovery from severe paralysis is generally slow.

DNA analysis of the HMBS, CPOX, and PPOX genes is performed by full gene sequencing of all exons (coding regions), 20-30 base pairs into the introns (including splice sites), and the promoter region. This methodology should identify >99% of gene mutations listed in the Human Gene Mutation Database as well as novel mutations.

Specimen Requirements:

20ml of whole blood in EDTA (anticoagulant) tubes (lavender top) OR extracted DNA (50?l with concentration of 200ng/?l).

Shipping: Ship at room temperature.

Turnaround Time: 10-14 days

CPT Codes: 83891, 83898x22, 83904x11, 83912

Consent Form: Porphyria Genetic Testing Consent [PDF]

Requisition Form: Porphyria Testing Requisition [PDF]