Webster's New World Medical Dictionary

will, living
See 
living will.
Willis, circle of
See 
circle of Willis.
Wilms tumor
A childhood form of kidney cancer
with a peak age of occurrence at 3 years of age. It is
sometimes associated with abnormalities of the uri-
nary tracts or other birth defects. Some cases are
related to defects in one of two genes referred to as
Wilms’ tumor 1 (WT1) or Wilms’ tumor 2 (WT2).
Symptoms can include abdominal pain, swelling,
and blood in the urine. Diagnosis is made by biopsy,
which can classify the tumors as having a favorable
histology (microscopic appearance) or an unfavor-
able histology, which is associated with a worse out-
come. The outcome is also reflected by the stage of
the tumor (extent of spread) at the time of diagno-
sis. Treatment involves surgery and chemotherapy;
sometimes radiation therapy is also recommended.
Wilms tumor has a very high cure rate, particularly
when detected as a localized tumor. Also known as
nephroblastoma.
Wilson disease
An inherited disorder of copper
metabolism that results in an abnormal accumula-
tion of copper in the body. Although the accumula-
tion of copper begins at birth, symptoms of the
disorder do not appear until later in life, between
the ages of 6 and 40. A diagnostic feature of the dis-
ease is a Kayser-Fleischer ring, a deep copper-
colored ring around the edge of the cornea that 
represents copper deposits in the eye. The main
clinical consequence of Wilson disease for most
affected persons is liver disease. In other patients
the first symptoms are nervous system or psychiatric
symptoms or both and include tremor, rigidity,
drooling, difficulty with speech, abrupt personality
change, grossly inappropriate behavior and inexpli-
cable deterioration of school or other work, neuro-
sis, and psychosis. Without proper treatment,
Wilson disease is always fatal, usually by age 30. If
treatment is begun early enough, symptomatic
recovery is usually complete, and a life of normal
length and quality can be expected. Wilson disease
is inherited in an autosomal recessive manner and
is due to mutation of the ATP7B gene on chromo-
some 13. The ATP7B gene encodes ATPase, a 
copper-transporting beta polypeptide.