Practical genetics for autosomal dominant polycystic kidney disease

Area of Science:

• Nephrology
• Medical Genetics

Background:

• Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disorder, causing end-stage renal disease in ~5% of North Americans.
• Characterized by progressive renal cyst development, ADPKD is primarily caused by mutations in PKD1 or PKD2 genes.
• PKD1 mutations typically result in more severe disease than PKD2 mutations, with earlier onset of kidney failure.

Purpose of the Study:

• To review the utility and limitations of diagnostic approaches for ADPKD.
• To present an integrated strategy for evaluating individuals with suspected ADPKD.
• To address diagnostic challenges posed by genetic and environmental modifiers causing disease variability.

Main Methods:

• Review of clinical predictors for ADPKD gene types.
• Evaluation of imaging-based diagnostic tests, including ultrasonography with age-dependent criteria.
• Analysis of molecular diagnostic methods such as DNA linkage and direct gene sequencing.

Main Results:

• Standard ultrasound criteria for PKD1 may have limited utility for milder PKD2 or when gene type is unknown.
• Recently developed ultrasound criteria show high predictive value for at-risk subjects of unknown gene type.
• Molecular testing offers diagnostic capabilities for equivocal imaging, indeterminate family history, or living kidney donor evaluations.

Conclusions:

• Accurate ADPKD diagnosis requires integrating clinical, imaging, and molecular data.
• Understanding diagnostic test performance is crucial for effective genetic counseling and patient management.
• Further research into genetic and environmental modifiers may improve ADPKD prognosis and treatment.