Wilms tumour

Wilms tumours are one of the most common solid tumours of
childhood, affecting 1 in 10 000 children. Wilms tumours are
usually unilateral, and the vast majority are sporadic. About
1% of Wilms tumours are hereditary, and of these about 20%
are bilateral. Wilms tumour is associated with aniridia,
genitourinary abnormalities, gonadoblastoma and mental
retardation (WAGR syndrome) in a small proportion of cases.
Identification of an interstitial deletion of chromosome 11 in
such cases localised a susceptibility gene to chromosome 11p13.
The Wilms tumour gene, WT1, at this locus has now been
cloned and acts as a tumour suppressor gene, with loss of
alleles on both chromosomes being detected in tumour tissue.
A second locus at 11p15 has also been implicated in Wilms
tumour. The insulin-like growth factor-2 gene (IGF2), is located
at 11p15 and causes Beckwith–Wiedemann syndrome, an
overgrowth syndrome predisposing to Wilms tumour. Children
with hemihypertrophy are at increased risk of developing
Wilms tumours and a recommendation has been made that
they should be screened using ultrasound scans and abdominal
palpation during childhood. A third gene predisposing to
Wilms tumour has been localised to chromosome 16q. These
genes are not implicated in familial Wilms tumour, which
follows autosomal dominant inheritance with reduced
penetrance, and there is evidence for localisation of a familial
predisposition gene at chromosome 17q.