disease in Persian and Exotic Shorthair cats Comparison between ultrasound and genetic testing for the early diagnosis of polycystic kidney

Dipartimento di Scienze Animali,Universita `di Milano, Facolta diMedicina Veterinaria, Via Celoria10, 20133 Milan, ItalyAutosomal-dominant polycystic kidney disease (AD-PKD) is common inPersians and Persians-related breeds. The aims of this study were to evaluate thesensitivity and specificity of early ultrasound examination and to compareultrasound and genetic testing for early diagnosis. Sixty-three Persians andseven Exotic Shorthairs were considered. All underwent ultrasonographic andgenetic testing (polymerase chain reaction/restriction fragment lengthpolymorphism (PCR/RFLP) assay) between 2.5 and 3.5 months of age (10e14weeks). With ultrasound, 41.4% showed renal cysts, while 37.1% were PKDpositive by genetic testing and DNA sequencing. Six cats with at least one renalcyst were negative by genetic testing, while only one cat negative at ultrasoundresulted positive at genetic test. DNA sequencing of three polycystic cats,negative by genetic test, revealed they were heterozygous for the mutation.Agreement was described by Cohen’s kappa that resulted 0.85, consideringgenetic test and DNA sequencing. Sensitivity and specificity of ultrasound were96.2% and 91%, respectively. Sensitivity was higher and specificity lower thanreported previously. The higher sensitivity could be due to improved technicalcapabilities of ultrasound machines and transducers. Other causes of PKD couldexplain the lower specificity. In conclusion, ultrasound resulted in a reliablediagnostic method for feline AD-PKD1 at early age and it should always be usedwith genetic testing, in order to reach a complete screening programme andeventually to identify other genetic mutations.Date accepted: 9 October 2008 2008 ESFM and AAFP. Published by Elsevier Ltd. All rights reserved.