LAUSR

INTRODUCTION P olycystic kidney disease (PKD) is a hereditary disease that is usually caused by PKD1 or PKD2 pathogenic mutation and that can be divided into 2 types by heredity. When symptoms present neonatally, the prevalence of autosomal recessive polycystic kidney disease (ARPKD) is from 1/10,000 to 1/40,000. Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease, which is also an adult-onset type. The incidence rate of ADPKD is estimated to be 1/400 to 1/1000. It is characterized by progressive enlargement of cysts. When it comes to the differential diagnosis of PKD, especially ADPKD, tuberous sclerosis complex (TSC) is mentioned. Tuberous sclerosis complex affects numerous organ systems and is known as an autosomal dominant inherited disorder that is usually caused by TSC1 (OMIM ID: 191100) or TSC2 (OMIM ID: 191115) gene mutation. The birth incidence of TSC is 1 in 5800. Triad syndrome, which includes skin lesions, mental retardation, and seizure, is the typical feature of this rare disease, but disease manifestations may vary significantly among individuals. Moreover, TSC can present as PKD. For an adult with renal injury, regardless of the confirmed family history, the diagnosis of PKD or TSC should not simply be satisfied with ultrasonography because of the similiar images of bilaterally dark cysts. Thus, further imaging examinations (computed tomography [CT] and magnetic resonance imaging) and genetic detection are quite helpful for diagnosis. Here we report a case that had been initially misdiagnosed as PKD by abdominal ultrasound but that turned out to be clinically diagnosed as TSC later and was finally diagnosed as TSC2/ PKD1 contiguous gene syndrome (PKDTS) by unique deletionmutation. To the best of our knowledge, it is a rare report demonstrating the heterozygous deletion mutation