Sorted By Test Name - Mayo Medical Laboratories

MARE
82141
changes in behavior, difficulties with language, rigidity, palsy, and saccadic (rapid) eye movement.
Symptoms generally begin between 40 and 60 years of age, with mean age of onset at approximately 45
years, and typically last between 5 and 10 years, progressing into severe dementia and mutism. The
presentation of frontotemporal dementia may be confused with other dementias, including Alzheimer
disease. It is important to distinguish between these different dementias because disease progression and
patient management are different for the various dementias. Based on the immunohistochemical staining,
there are 2 main subtypes of FTLD: tau-positive FTLD and tau-negative FTLD with ubiquitin-positive
inclusions (FTLD-U). Mutations in the MAPT gene have been identified in patients with tau-positive
FTLD; mutations in the progranulin gene (GRN) have been identified in patients with FTLD-U. Both
MAPT and GRN are located on chromosome 17q21. The MAPT gene encodes the microtubule-associated
tau protein. A number of mutations have been identified in the MAPT gene that result in aggregation of
the tau protein. Although there is variable expression of disease presentation and severity within and
between families, the hallmark neurologic lesion constitutes tau-positive protein inclusion bodies. Most
clinically significant mutations are found in exons 9 through 13. Several intronic mutations, associated
with alternative splicing of the mRNA, contribute to the variability of expression of the disease traits.
Mutations in the MAPT gene have also been identified in cases of progressive supranuclear palsy,
corticobasal degeneration, and dementia with epilepsy.
Useful For: Screening of at-risk individuals when a mutation in the MAPT 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. Rademakers R, Cruts M, van Broeckhoven C: The role of tau (MAPT) in
frontotemporal dementia and related tauopathies. Hum Mutat 2004 Oct;24(4):277-295 2. Houlden H,
Baker M, Adamson J, et al: Frequency of tau mutations in three series of non-Alzheimerâ€s
degenerative dementia. Ann Neurol 1999 Aug;46(2):243-248 3. Goedert M: Tau protein and
neurodegeneration. Semin Cell Dev Biol 2004 Feb;15(1):45-49 4. Dumanchin C, Camuzat A, Campion D,
et al: Segregation of a missense mutation in the microtubule-associated protein tau gene with familial
frontotemporal dementia and parkinsonism. Hum Mol Genet 1998 Oct;7(11):1825-1829
Mare's Milk, 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
bronchospasm) in infants and children less than 5 years due to food sensitivity (milk, egg, soy, and wheat
proteins) followed by respiratory disease (rhinitis and asthma) in older children and adults due to
sensitivity to inhalant allergens (dust mite, mold, and pollen inhalants).
Useful For: Testing for IgE antibodies may be useful to establish the diagnosis of an allergic disease
and to define the allergens responsible for eliciting signs and symptoms. Testing also may be useful to
identify allergens which may be responsible for allergic disease and/or anaphylactic episode, to confirm
sensitization to particular allergens prior to beginning immunotherapy, and to investigate the specificity of
allergic reactions to insect venom allergens, drugs, or chemical allergens.
Interpretation: Detection of IgE antibodies in serum (Class 1 or greater) indicates an increased
likelihood of allergic disease as opposed to other etiologies and defines the allergens that may be
responsible for eliciting signs and symptoms. The level of IgE antibodies in serum varies directly with the
concentration of IgE antibodies expressed as a class score or kU/L.
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