05-29-2009, 11:07 AM
Gyrate atrophy is a rare autosomal recessive genetic disorder
caused by a deficiency of ornithine aminotransferase. Affected individuals
experience progressive chorioretinal degeneration. The gene for ornithine
aminotransferase has been cloned, its structure has been determined, and
mutations in affected individuals have been extensively studied. Which of
the mutations listed below best fits with test results showing normal Southern
blots with probes from all ornithine aminotransferase exons but absent
enzymatic activity?
a. Duplication of entire gene
b. Two-kb deletion in coding region of gene
c. Two-kb insertion in coding region of gene
d. Deletion of entire gene
e. Missense mutation
caused by a deficiency of ornithine aminotransferase. Affected individuals
experience progressive chorioretinal degeneration. The gene for ornithine
aminotransferase has been cloned, its structure has been determined, and
mutations in affected individuals have been extensively studied. Which of
the mutations listed below best fits with test results showing normal Southern
blots with probes from all ornithine aminotransferase exons but absent
enzymatic activity?
a. Duplication of entire gene
b. Two-kb deletion in coding region of gene
c. Two-kb insertion in coding region of gene
d. Deletion of entire gene
e. Missense mutation