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Porphyria Educational Services


PORPHYRIA EDUCATIONAL SERVICES BULLETIN Vol. 1 No. 10  March 1999
Variegate Porphyria

Variegate porphyria is one of the eight type of currently recognized
porphyrias.

Variegate porphyria is an autosomal dominant disorder.
Variegate porphyria is a metabolic inherited disease.

VP, by which is commonly known, is considered to be less common than acute
intermittent porphyria in the U.S.

VP has either cutaneous or neurological manifestations or both.
When a VP patient is exposed to sunlight there is increased fragility of
the skin with bullae formation. There also can be  erosions, and scarring.

Chronic skin thickening and facial hypertrichosis may also occur.
The acute attacks of neurological dysfunction present the same as the
manifestations described in acute intermittent porphyria.

The distinction of acute intermittent porphyria, coproporphyria, and
variegate porphyria is not critical to care since prophylaxis and treatment
of the acute attack are managed the same.

What are the laboratory findings for VP?
During acute attacks the excretion of urinary ALA and PBG is increased.
When asymptomatic or with cutaneous lesions only an increase in
uroporphyrin and coproporphyrin may be noted.

Because of this it can be confused with the findings of porphyria cutanea
tarda. The increase in fecal protoporphyrin seen in both acute and
asymptomatic periods allows the differentiation of the two disorders.

Treatment for VP is like for HCP and AIP.
Management of these patients is the same as for the acute hepatic
porphyrias. The treatment of the cutaneous manifestations can be difficult
.
Please note that the beta carotene therapy which is used in protoporphyria
is not effective.

For the neurological symptoms the glucose intrevenous therapy is given the
same as in HCP and AIP.

DNA tests  in VP

The most widely applicable test is that for the R59W mutation which
accounts for over 95% of South African cases of VP.
With this test however  it is uniformly effective in detecting both silent
and expressed porphyria in families who carry the R59W mutation.
However this same test is useless in families with forms of porphyria other
than VP, and in VP families with non-R59W VP.

Also this test does not differentiate symptomatic from asymptomatic VP.

R59W screening should however be used as a first-line of investigation in
family follow-up studies of patients known to have R59W-positive VP.
DNAQ testing  may also be used for screening patients in whom the clinical
suspicion of VP is low.

Where the suspicion is high however, a negative result must be followed
by the standard biochemical porphyrin profile to exclude non-R59W VP, PCT,
AIP and all  the rarer forms of porphyria.