Compound heterozygousPKHD1variants cause a wide spectrum of ductal plate malformations

Histopathology and molecular pathology confirmed a diagnosis of atypical Caroli's syndrome: a case report

Caroli's syndrome is a congenital disease characterized by dilation of intrahepatic bile ducts and congenital hepatic fibrosis. It is a rare condition in clinical work. Typically, the diagnosis of this disease is confirmed through medical imaging. Here, we report a case of atypical Caroli's syndrome in a patient who presented with recurrent upper gastrointestinal tract bleeding. The patient underwent imaging examinations, liver biopsy and whole exome sequencing. The results of the imaging examination were non-specific. However, with the aid of pathological examination, the patient was diagnosed with Caroli's syndrome. In conclusion, for cases where the imaging presentation of Caroli's syndrome is inconclusive, an accurate diagnosis should rely on pathology. By discussing this specific case, our aim is to enhance readers' understanding of this disease, provide valuable information that can aid in the early detection and appropriate management of Caroli's syndrome, ultimately improving patient outcomes.

Rare variants in PKHD1 associated with Caroli syndrome: Two case reports

BACKGROUND

Caroli disease (CD, OMIM #600643) is a rare autosomal recessive disorder characterized by polycystic segmental dilatation of the intrahepatic bile ducts and extreme variability in age of onset and clinical manifestations. When congenital hepatic fibrosis is associated with the polycystic dilatation of the biliary tract, the condition is referred as Caroli syndrome. The disease is thought to be caused by pathogenic variants in the PKHD1 gene (OMIM *606702).

METHOD

We report the clinical, biochemical, and molecular characterization of three patients with a clinical suspicion of CS belonging to two different families. The genetic screening was performed using a target custom panel and sequencing was performed on Illumina platform.

RESULTS

Genetic analysis revealed the presence of rare variants in the PKHD1 gene of the analyzed patients. In the first case, and his younger sister, two pathogenic variants (c.2702A>C and c.4870C>T) were found to be associated with a hepatic phenotype at clinical onset, followed by renal disease probably age-related; while in the second case, one pathogenic variant (c.5879C>G) and a complex allele with uncertain clinical significance [c.3407A>G; c.8345G>C; c.8606C>A] were found to be associated with a severe hepatic phenotype.

CONCLUSION

The identification of the genetic causes of the disease and their relationship with the clinical phenotype could have a favorable impact on clinical management and complication prevention.

Imaging manifestations of Caroli disease with autosomal recessive polycystic kidney disease: a case report and literature review

Background

Both Caroli disease (CD) and autosomal recessive polycystic kidney disease (ARPKD) are autosomal recessive disorders, which are more commonly found in infants and children, for whom surviving to adulthood is rare. Early diagnosis and intervention can improve the survival rate to some extent. This study adopted the case of a 26-year-old pregnant woman to explore the clinical and imaging manifestations and progress of CD concomitant with ARPKD to enable a better understanding of the disease.

Case presentation

A 26-year-old pregnant woman was admitted to our hospital for more than 2 months following the discovery of pancytopenia and increased creatinine. Ultrasonography detected an enlarged left liver lobe, widened hepatic portal vein, splenomegaly, and dilated splenic vein. In addition, both kidneys were obviously enlarged and sonolucent areas of varying sizes were visible, but color Doppler flow imaging revealed no abnormal blood flow signals. The gestational age was approximately 25 weeks, which was consistent with the actual fetal age. Polyhydramnios was detected but no other abnormalities were identified. Magnetic resonance imaging revealed that the liver was plump, and polycystic liver disease was observed near the top of the diaphragm. The T1 and T2 weighted images were the low and high signals, respectively. The bile duct was slightly dilated; the portal vein was widened; and the spleen volume was enlarged. Moreover, the volume of both kidneys had increased to an abnormal shape, with multiple, long, roundish T1 and T2 abnormal signals being observed. Magnetic resonance cholangiopancreatography revealed that intrahepatic cystic lesions were connected with intrahepatic bile ducts. The patient underwent a genetic testing, the result showed she carried two heterozygous mutations in PKHD1. The patient was finally diagnosed with CD with concomitant ARPKD. The baby underwent a genetic test three months after birth, the result showed that the patient carried one heterozygous mutations in PKHD1, which indicated the baby was a PKHD1 carrier.

Conclusions

This case demonstrates that imaging examinations are of great significance for the diagnosis and evaluation of CD with concomitant ARPKD.

The Role of Next Generation Sequencing in the Differential Diagnosis of Caroli's Syndrome

We report the case of a 41-year-old man on conservative treatment for more than 20 years for chronic renal insufficiency, chronic hepatitis and recurrent cholangitis. Following lengthy and extensive diagnostics, the differential diagnosis included primary sclerosing cholangitis and Caroli’s disease (CD). To solve the diagnostic challenge, next generation sequencing (NGS) was performed to distinguish between the disorders possibly present in the patient. The diagnosis of CD became evident after two rare known pathogenic mutations were detected in the poly-ductin 1 (PKHD1) gene, c.370C>T (p.Arg124Ter) and c.4870C>T (p.Arg1624Trp). In this case, NGS was instrumental in solving the diagnostic challenge, allowing differentiation among the proposed genetic and non-genetic ethiologies.

A human ciliopathy with polycystic ovarian syndrome and multiple subcutaneous cysts: A rare case report

RATIONALE

Ciliopathies is a group of clinically and genetically overlapping disorders due to cilia abnormalities and multiple organ systems are involved in.

PATIENT CONCERNS

We present a young female patient who showed renal function impairment, Caroli syndrome (CS), liver cirrhosis, polycystic ovarian syndrome, and multiple subcutaneous cysts.

DIAGNOSES

The patient was diagnosed with ciliopathy according to the clinical manifestations and whole-genome sequencing.

INTERVENTIONS

She received treatment of intravenous albumin, polyene phosphatidyl choline, furosemide, and antisterone.

OUTCOMES

The patient showed clinical improvement in her edema and liver tests, and ultrasonography revealed that the ascites had disappeared. Unfortunately, the edema relapsed a year later. The patient received the same treatment as before, and there was clinical improvement of the edema. Since the family cannot afford liver and kidney transplantation, the patient only accepted symptomatic treatment.

LESSONS

Polycystic ovarian syndrome and multiple subcutaneous cysts have never before been reported to be associated with ciliopathy. This finding could remind doctors to consider the possibility of ciliopathy disease for patients suffering from similar conditions. In addition, the phenotype of the patient differs from those of patients reported with the same mutations, which also reminds doctors that the clinical manifestation of a given mutation may show patient-specific differences. This case report extends the phenotypic spectrum of ciliopathy, and these findings might represent a new ciliopathy syndrome, which could facilitate the diagnosis of ciliopathies.

Exome Sequencing Discerns Syndromes in Patients from Consanguineous Families with Congenital Anomalies of the Kidneys and Urinary Tract

Congenital anomalies of the kidneys and urinary tract (CAKUT) are the leading cause of CKD in children, featuring a broad variety of malformations. A monogenic cause can be detected in around 12% of patients. However, the morphologic clinical phenotype of CAKUT frequently does not indicate specific genes to be examined. To determine the likelihood of detecting causative recessive mutations by whole-exome sequencing (WES), we analyzed individuals with CAKUT from 33 different consanguineous families. Using homozygosity mapping and WES, we identified the causative mutations in nine of the 33 families studied (27%). We detected recessive mutations in nine known disease-causing genes: ZBTB24, WFS1, HPSE2, ATRX, ASPH, AGXT, AQP2, CTNS, and PKHD1 Notably, when mutated, these genes cause multiorgan syndromes that may include CAKUT as a feature (syndromic CAKUT) or cause renal diseases that may manifest as phenocopies of CAKUT. None of the above monogenic disease-causing genes were suspected on clinical grounds before this study. Follow-up clinical characterization of those patients allowed us to revise and detect relevant new clinical features in a more appropriate pathogenetic context. Thus, applying WES to the diagnostic approach in CAKUT provides opportunities for an accurate and early etiology-based diagnosis and improved clinical management.