Sorted By Test Name - Mayo Medical Laboratories

CPOXK
61264
CRAB
82745
Interpretation: An interpretive report will be provided.
Reference Values:
An interpretive report will be provided.
Clinical References: 1. Siegesmund M, van Tuyll van Serooskerken AM, Poblete-Gutierrez P, et al:
The acute hepatic porphyrias: current status and future challenges. Best Pract Res Clin Gastroenterol 2010
Oct;24(5):593-605 2. Anderson KE, Bloomer JR, Bonkovsky HL, et al: Recommendations for the
diagnosis and treatment of the acute porphyrias. Ann Intern Med 2005 Mar 15;142(6):439-450 3. Schmitt,
C, Gouya L, Malonova E, et al: Mutations in human CPO gene predict clinical expression of either
hereditary coproporphyria or erythropoietic harderoporphyria. Hum Mol Genet 2005;14(20):3089-3098
CPOX Gene, Known Mutation
Clinical Information: Hereditary coproporphyria (HCP) is an autosomal dominant (AD) acute
hepatic porphyria that presents with clinical attacks of neurologic dysfunction, commonly characterized as
abdominal pain. However, these acute attacks are variable and can include vomiting, diarrhea,
constipation, urinary retention, acute episodes of neuropathic symptoms, psychiatric symptoms, seizures,
respiratory paralysis, tachycardia, and hypertension. Respiratory paralysis can progress to coma and
death. HCP is also associated with cutaneous manifestations, including edema, sun-induced erythema,
acute painful photodermatitis, and urticarial. In some cases, patients present with isolated photosensitivity.
HCP is caused by AD mutations in the CPOX gene. Mutations may have incomplete penetrance.
Homozygous mutations in CPOX have been reported in association with a more severe, phenotypically
distinct condition called harderoporphyria that is characterized by neonatal hemolytic anemia with mild
residual anemia during childhood and adulthood. Affected patients may also present with skin lesions and
fecal harderoporphyin accumulation may be observed. This condition is inherited in an autosomal
recessive pattern and all patients identified to date have been heterozygous or homozygous for the K404E
mutation. For HCP, acute attacks may be prevented by avoiding both endogenous and exogenous triggers.
These triggers include porphyrogenic drugs, hormonal contraceptives, fasting, alcohol, tobacco, and
cannabis. Fecal porphyrins analysis and quantitative urinary porphyrins analysis are helpful in
distinguishing HCP from other forms of acute porphyria.
Useful For: Predictive testing for hereditary coproporphyria or harderoporphyria when mutation in the
CPOX gene has been identified in an affected family member
Interpretation: An interpretive report will be provided.
Reference Values:
An interpretive report will be provided.
Clinical References: 1. Siegesmund M, van Tuyll van Serooskerken AM, Poblete-Gutierrez P, et al:
The acute hepatic porphyrias: current status and future challenges. Best Pract Res Clin Gastroenterol 2010
Oct;24(5):593-605 2. Anderson KE, Bloomer JR, Bonkovsky HL, et al: Recommendations for the
diagnosis and treatment of the acute porphyrias. Ann Intern Med 2005 Mar 15;142(6):439-450 3. Schmitt,
C, Gouya L, Malonova E, et al: Mutations in human CPO gene predict clinical expression of either
hereditary coproporphyria or erythropoietic harderoporphyria. Hum Mol Genet 2005;14(20):3089-3098
Crab, IgE
Clinical Information: Clinical manifestations of immediate hypersensitivity (allergic) diseases are
caused by the release of proinflammatory mediators (histamine, leukotrienes, and prostaglandins) from
immunoglobulin E (IgE)-sensitized effector cells (mast cells and basophils) when cell-bound IgE
antibodies interact with allergen. In vitro serum testing for IgE antibodies provides an indication of the
immune response to allergen(s) that may be associated with allergic disease. The allergens chosen for
testing often depend upon the age of the patient, history of allergen exposure, season of the year, and
clinical manifestations. In individuals predisposed to develop allergic disease(s), the sequence of
sensitization and clinical manifestations proceed as follows: eczema and respiratory disease (rhinitis and
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