An update on ductal plate malformations and fibropolycystic diseases of the liver

Nephronophthisis 13 caused by WDR19 variants with pancytopenia: case report

We present a case of nephronophthisis 13 that resulted from WDR19 variants. The patient, a nine-year-old Japanese boy, had detection of mild proteinuria during a school urine screening. Urinalysis revealed mild proteinuria without hematuria. Blood tests indicated pancytopenia, mild elevation of liver enzymes, and kidney dysfunction. Ultrasound examination disclosed hepatosplenomegaly. Abdominal computed tomography and bone marrow assessments ruled out malignant tumors. Subsequent kidney and liver biopsies suggested nephronophthisis and congenital hepatic fibrosis. Furthermore, comprehensive genetic analysis through next-generation sequencing revealed compound heterozygous variants in WDR19 (NM_025132.4), including the previously reported c.3533G > A, p.(Arg1178Gln), and c.3703G > A, p.(Glu1235Lys) variants, confirming the diagnosis of nephronophthisis 13. There is potential need for liver and kidney transplantation in patients with nephronophthisis and hepatic fibrosis. Early diagnosis is therefore crucial to mitigate delays in treating complications associated with kidney and hepatic insufficiency and to facilitate preparation of transplantation. To achieve early diagnosis of nephronophthisis, it is imperative to consider it as a differential diagnosis when extrarenal symptoms and kidney dysfunction coexist, particularly when mild proteinuria is observed through opportunistic urinalysis. Genetic testing is important because nephronophthisis manifests as diverse symptoms, necessitating an accurate diagnosis. Next-generation sequencing was shown to be invaluable for the genetic diagnosis of nephronophthisis, given the numerous identified causative genes.

Case report: Rare genetic liver disease - a case of congenital hepatic fibrosis in adults with autosomal dominant polycystic kidney disease

Congenital hepatic fibrosis (CHF) is considered to be a rare autosomal recessive hereditary fibrocystic liver disease, mainly found in children. However, cases of adult CHF with autosomal dominant polycystic kidney disease (ADPKD) caused by PKD1 gene mutation are extremely rare. We report a 31-year-old female patient admitted for esophageal and gastric variceal bleeding. Physical examination revealed significant splenomegaly, biochemical tests showed a slight increase in liver enzymes, and a decrease in platelet count. Imaging examinations showed significant dilatation of the common bile duct and intrahepatic bile ducts, as well as multiple renal cysts. Liver biopsy revealed enlarged portal areas, bridging fibrosis, and numerous variably shaped small bile ducts. Genetic testing identified two unique mutations in the PKD1 gene, identified as biallelic mutations compound heterozygous mutations composed of a mutation inherited from the father (c.8296 T > C) and one from the mother (c.9653G > C). Based on multiple test results, the patient was diagnosed with the portal hypertension type CHF associated with ADPKD. During her initial hospital stay, the patient underwent endoscopic treatment for gastrointestinal bleeding. To date, the patient has recovered well. Moreover, a significant reduction in varices was observed in a gastroscopy examination 18 months later.

Severe polycystic liver disease in a cat

Case summary

Ductal plate malformations (DPMs) are poorly documented in the veterinary literature, particularly those of the polycystic liver disease (PCLD) phenotype. A 13-year-old female spayed cat presented with progressive icterus, abdominal distension, weight loss and elevated liver enzymes. Initial empirical treatment consisting of amoxicillin/clavulanate, ursodiol and later prednisolone was attempted; however, clinical signs progressed. On abdominal ultrasound, numerous large hepatic cystic masses were noted, characterized by an anechoic center with a heterogeneous, hyperechoic wall. A post-mortem examination confirmed numerous hepatic cysts, the larger of which resulted in hemorrhage and subsequent hemoabdomen. Histologically, these cysts were determined to be of biliary origin, and a diagnosis of PCLD was assigned.

Relevance and novel information

Herein, we present a detailed report of clinical, gross and histologic findings in a cat clinically affected by PCLD. This case demonstrates that cysts present in this congenital disease can ultimately lead to hepatobiliary malfunction and clinical decline via marked expansion of cysts, compression of the liver and hemoabdomen from cyst rupture. DPMs, specifically PCLD, should be considered in cats presenting with multifocal large hepatic cysts.

Polycystic Liver Disease: Pathophysiology, Diagnosis and Treatment

Polycystic liver disease (PLD) is a clinical condition characterized by the presence of more than 10 cysts in the liver. It is a rare disease Of genetic etiology that presents as an isolated disease or assoc\iated with polycystic kidney disease. Ductal plate malformation, ciliary dysfunction, and changes in cell signaling are the main factors involved in its pathogenesis. Most patients with PLD are asymptomatic, but in 2–5% of cases the disease has disabling symptoms and a significant reduction in quality of life. The diagnosis is based on family history of hepatic and/or renal polycystic disease, clinical manifestations, patient age, and polycystic liver phenotype shown on imaging examinations. PLD treatment has evolved considerably in the last decades. Somatostatin analogues hold promise in controlling disease progression, but liver transplantation remains a unique curative treatment modality.