Should we screen for intracranial aneurysms in children with autosomal dominant polycystic kidney disease?

Intracranial Aneurysms in Autosomal Dominant Polycystic Kidney Disease: A Practical Approach to Screening and Management

Autosomal dominant polycystic kidney disease (ADPKD), the most prevalent genetic kidney disorder, is characterized by diffuse kidney cysts, hypertension, and progressive kidney function decline, often leading to kidney failure by the age of 60 years. Compared with the general population, patients with ADPKD have an increased risk for development of saccular intracranial aneurysms (IAs), which can lead to intracranial bleeding and result in significant disability and mortality. Of both modifiable and nonmodifiable risk factors, the most significant is a family history of IAs or aneurysm rupture. Other contributing factors include hypertension, cigarette smoking, age, and sex. Most IAs currently detected during screening tests are small and located in the anterior circulation. Intracranial aneurysms can be manifested with thunderclap headache, which may be indicative of subarachnoid hemorrhage. Less commonly, IAs cause symptoms related to mass effect with focal neurologic deficits. Subarachnoid hemorrhage is particularly concerning, given its high case-fatality rate, which remains around 35% despite advances in neurologic care. Therefore, control of risk factors, early detection, and treatment when indicated are important to prevent adverse outcomes. Screening for IAs in ADPKD remains controversial and can be approached either universally (screening of all ADPKD patients) or selectively (screening of high-risk patients). The preferred imaging modality is brain magnetic resonance angiography without contrast enhancement or alternatively computed tomography angiography. This review provides a practical guide for medical teams managing patients with ADPKD, detailing the characteristics of IAs and their associated symptoms. It presents an algorithm for risk assessment and screening along with recommendations for treatment and follow-up care.

Polycystic Kidney Disease in Children: The Current Status and the Next Horizon

Autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive polycystic kidney disease (ARPKD) are inherited disorders that share many features such as kidney cysts, hypertension, urinary concentrating defects, and progressive chronic kidney disease. Underlying pathogenic mechanisms for both include cilia dysfunction and dysregulated intracellular signaling. ADPKD has been traditionally regarded as an adult-onset disease, whereas ARPKD has been classically described as an infantile or childhood condition. However, clinicians must recognize that both disorders can present across all age groups ranging from fetal life and infancy to childhood and adolescence, as well as adulthood. Here we highlight the points of overlap and distinct features for these disorders with respect to pathogenesis, diagnostic modalities (radiological and genetic), clinical assessment, and early therapeutic management. In particular, we consider key issues at two critical points for transition of care, i.e., fetal life to infancy and adolescence to adulthood. These timepoints are poorly covered in the extant literature. Therefore, we recommend guiding principles for transitions of clinical care at these critical junctures in the lifespan. While there is no cure for polycystic kidney disease (PKD), recent insights into pathogenic mechanisms have identified promising therapeutic targets that are currently being evaluated in a growing portfolio of clinical trials. We summarize the key findings from these largely adult-based trials and discuss the implications for designing child-focused studies. Finally, we look forward to the next horizon for childhood PKD, highlighting gaps in our current knowledge, and discussing future directions and strategies to attenuate the full burden of disease for children affected with PKD.

Matching clinical and genetic data in pediatric patients at risk of developing cystic kidney disease

BACKGROUND

Cystic kidney disease is a heterogeneous group of hereditary and non-hereditary pathologic conditions, associated with the development of renal cysts. These conditions may be present both in children and adults. Cysts can even be observed already during the prenatal age, and pediatric patients with cysts need to be clinically monitored. An early clinical and genetic diagnosis is therefore mandatory for optimal patient management. The aim of this study was to perform genetic analyses in patients with echographic evidence of kidney cysts to provide an early molecular diagnosis.

METHODS

A cohort of 70 pediatric patients was enrolled and clinically studied at the time of first recruitment and at follow-up. Genetic testing by clinical exome sequencing was performed and a panel of genes responsible for "cystic kidneys" was analyzed to identify causative variants. Sanger validation and segregation studies were exploited for the final classification of the variants and accurate genetic counseling.

RESULTS

Data showed that 53/70 of pediatric patients referred with a clinical suspicion of cystic kidney disease presented a causative genetic variant. In a significant proportion of the cohort (24/70), evidence of hyper-echogenic/cystic kidneys was already present in the prenatal period, even in the absence of a positive family history.

CONCLUSIONS

This study suggests that cystic kidney disease may develop since the very early stages of life and that screening programs based on ultrasound scans and genetic testing play a critical role in diagnosis, allowing for better clinical management and tailored genetic counseling to the family.

Unraveling the Complexity of Childhood Polycystic Kidney Disease: A Case Study of Three Sisters

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disorder, estimated to affect 1 in 1000 people. It displays a high level of variability in terms of onset and severity among affected individuals within the same family. In this case study, three sisters (4, 8, and 10 years of age) were suspected of having ADPKD due to their positive family history. While the two younger sisters aged 8 and 4 showed no disease complications and had normal kidney function, the oldest sister was found to have no dipping status on ambulatory blood pressure measurement (ABPM). Two of the sisters were discovered to have a PKD1 mutation, while the third sister aged 8 was heterozygous for TTC21B c.1593_1595del, p. (Leu532del), which is a variant of uncertain significance (VUS). Environmental factors and genetic modifying factors are believed to contribute to the phenotypic variability observed in ADPKD. Identifying and understanding potential genetic and environmental modifiers of ADPKD could pave the way to targeted treatments for childhood ADPKD.

Autosomal dominant polycystic kidney disease in young adults

BACKGROUND

The clinical manifestations of autosomal dominant polycystic kidney disease (ADPKD) usually appear in adulthood, however pediatric series report a high morbidity. The objective of the study was to analyze the clinical characteristics of ADPKD in young adults.

METHODS

Family history, hypertension, albuminuria, estimated glomerular filtration rate (eGFR) and imaging tests were examined in 346 young adults (18-30 years old) out of 2521 patients in the Spanish ADPKD registry (REPQRAD). A literature review searched for reports on hypertension in series with more than 50 young (age <30 years) ADPKD patients.

RESULTS

The mean age of this young adult cohort was 25.24 (SD 3.72) years. The mean age at diagnosis of hypertension was 21.15 (SD 4.62) years, while in the overall REPQRAD population was aged 37.6 years. The prevalence of hypertension was 28.03% and increased with age (18-24 years, 16.8%; 25-30 years, 36.8%). Although prevalence was lower in women than in men, the age at onset of hypertension (21 years) was similar in both sexes. Mean eGFR was 108 (SD 21) mL/min/1.73 m2, 38.0% had liver cysts and 3.45% of those studied had intracranial aneurysms. In multivariate analyses, hematuria episodes and kidney length were independent predictors of hypertension (area under the curve 0.75). The prevalence of hypertension in 22 pediatric cohorts was 20%-40%, but no literature reports on hypertension in young ADPKD adults were found.

CONCLUSIONS

Young adults present non-negligible ADPKD-related morbidity. This supports the need for a thorough assessment of young adults at risk of ADPKD that allows early diagnosis and treatment of hypertension.