Splice site mutations in the ATP7A gene

Area of Science:

• Genetics
• Molecular Biology
• Biochemistry

Background:

• Menkes disease (MD) and Occipital Horn Syndrome (OHS) are rare genetic disorders.
• These conditions result from mutations in the ATP7A gene, affecting copper transport.
• Splice site mutations are a significant cause of these allelic disorders.

Purpose of the Study:

• To identify and characterize novel splice site mutations in the ATP7A gene.
• To investigate the in vivo effects of these mutations on mRNA transcripts.
• To correlate in silico predictions of splicing effects with observed clinical phenotypes.

Main Methods:

• Mutation screening in patients with MD and OHS.
• In silico analysis using the Human Splice Finder tool.
• In vivo analysis of mRNA transcripts from patient samples.

Main Results:

• 33 novel splice site mutations were identified in ATP7A.
• In silico predictions accurately reflected in vivo splicing defects for most mutations.
• Classical MD patients predominantly showed significant splicing effects and absence of wild-type transcript.
• Milder phenotypes (OHS) often had mutations with no significant predicted splicing effect and retained wild-type transcript.

Conclusions:

• The presence of wild-type ATP7A transcript correlates with milder phenotypes in MD and OHS.
• In silico tools like Human Splice Finder are valuable for predicting the functional impact of splice site mutations.
• Understanding genotype-phenotype correlations aids in diagnosing and managing Menkes disease and Occipital Horn Syndrome.