Molecular Genetics of X-linked Disease 
Lowe's Syndrome 
Lowe's syndrome is an uncommon X-linked 
disease that causes mental retardation, cataracts, 
and kidney dysfunction. The cause is unknown. 
As with choroideremia, our strategy is to identify 
the Lowe's syndrome gene through information 
about its location. 
Linkage analysis with restriction fragment 
length polymorphisms localized the gene to the 
Xq25 region of the X chromosome. Collaborators 
in the United Kingdom have identified a Lowe's 
syndrome patient in whom the disease is caused 
by a break in Xq25 that has disrupted the gene, 
splitting it into two pieces separated on different 
chromosomes. In collaboration with David Nel- 
son (Baylor College of Medicine) , we have iden- 
tified a segment of DNA in a YAC that spans the 
region of the break in this patient. Segments of 
DNA from within this YAC have been shown to 
contain gene sequences that are candidates for 
containing the Lowe's syndrome gene. 
Our goal is to understand the biochemical pro- 
cesses that, when defective, lead to brain, lens, 
and kidney dysfunction and damage. Insights into 
normal lens formation and normal brain and kid- 
ney function could result, and methods for im- 
proved diagnosis and therapy for the disease may 
be found. 
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