Background
A disease similar to human Alexander disease (AxD) was phenotypically described in several dog breeds, but the causal genetic variants were unknown. The disease is a fatal neurodegenerative disorder due to astrocyte dysfunction. The characteristic pathological feature are widespread and abundant astrocytic protein aggregates (Rosenthal fibers), which mainly consist of glial fibrillary acidic protein (GFAP). In humans, all genetic causes of AxD are mutations in GFAP, mostly dominant de novo variants arising from two mutation hotspots. In a Labrador Retriever with a juvenile form of the disease a GFAP mutation was identified, which is orthologous to a heterozygous de novo dominant hotspot variant, known to cause a severe phenotype in humans.
Test specific information
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Age
Symptoms will develop at a young age. Within a few hours to a maximum of several weeks after birth, the characteristics that go with these genetic effects will become visible.
Throughput
Normally the result can be expected within 15 working days. This turn-around-time starts when both the sample and the fully filled-out and signed submission form have been received.
Location of disease or trait
This disease is present in the entire body, but causes main effects in the internal organs such as stomach, intestinal tract, liver and / or kidneys. In a number of cases, the disease affects one major internal organ.
Breed dependence
This DNA test is available for the following breeds: Labrador Retriever.
Sample type
For this DNA test we accept the following materials: Blood EDTA, Blood Heparin, Semen, Swab, Tissue. Please contact PharmaDNA if you wish to submit other material as listed.
Result
An animal can be free and has in that situation two healthy alleles. When used in breeding this animal will not become ill due to the disease. It cannot spread the disease in the population. An animal can be carrier and has in that situation one healthy and one disease allele. When used in breeding 50 percent of the offspring will receive the disease allele. Carriers will also become ill. An animal can be affected and has in that situation two disease alleles. When used in breeding all offspring will also receive the disease allele. Affected will also become ill.
Inheritance
This genetic factor is inherited in an autosomal, dominant, mode. This means, that the individual can be free of the mutation (homozygote normal), affected (homozygous affected) or carrier (heterozygous affected). Both carriers and affected individuals will show symptoms of the mutation.
Severity of Disease
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