Asthma is a clinically heterogeneous genetic disease, and its pathogenesis is incompletely understood. Genome-wide association studies link ORM (yeast)-Like protein isoform 3 [corrected] (ORMDL3), a member of the ORM gene family, to nonallergic childhood-onset asthma. Orm proteins negatively regulate sphingolipid (SL) synthesis by acting as homeostatic regulators of serine palmitoyl-CoA transferase (SPT), the rate-limiting enzyme of de novo SL synthesis, but it is not known how SPT activity or SL synthesis is related to asthma. The present study analyzes the effect of decreased de novo SL synthesis in the lung on airway reactivity after administration of myriocin, an inhibitor of SPT, and in SPT heterozygous knockout mice. We show that, in both models, decreased de novo SL synthesis increases bronchial reactivity in the absence of inflammation. Decreased SPT activity affected intracellular magnesium homeostasis and altered the bronchial sensitivity to magnesium. This functionally links decreased de novo SL synthesis to asthma and so identifies this metabolic pathway as a potential target for therapeutic interventions.

Pheochromocytoma (PCC) and paraganglioma (PGL) are rare chromaffin cell tumors which secrete catecholamines and form part of the family of neuroendocrine tumors. Although a rare cause of secondary hypertension in pediatrics, the presentation of hypertension in these patients is characteristic, and treatment is definitive. The gold standard for diagnosis is via measurement of plasma free metanephrines, with imaging studies performed for localization, identification of metastatic lesions and for surgical resection. Preoperative therapy with alpha-blocking agents, beta blockers, and potentially tyrosine hydroxylase inhibitors aid in a safe pre-, intra- and postoperative course. PCC and PGL are inherited in as much as 80% of pediatric cases, and all patients with mutations should be followed closely given the risk of recurrence and malignancy. While the presentation of chromaffin cell tumors has been well described with multiple endocrine neoplasia, NF1, and Von Hippel–Lindau syndromes, the identification of new gene mutations leading to chromaffin cell tumors at a young age is changing the landscape of how clinicians approach such cases. The paraganglioma–pheochromocytoma syndromes (SDHx) comprise familial gene mutations, of which the SDHB gene mutation carries a high rate of malignancy. Since the inheritance rate of such tumors is higher than previously described, genetic screening is recommended in all patients, and lifelong follow-up for recurrent tumors is a must. A multidisciplinary team approach allows for optimal health-care delivery in such children. This review serves to provide an overview of pediatric PCC and PGL, including updates on the preferred methods of imaging, guidelines on gene testing as well as management of hypertension in such patients.

Chronic kidney disease is complex in both adults and children, but the disease is far from the same between these populations. Here we review the marked differences in etiology, comorbidities, impact of disease on growth and quality of life, issues unique to adolescents and transitions to adult care, and special considerations of congenital kidney and urinary tract anomalies for transplantation.

Introduction There is a paucity of information about risk behaviors in adolescents with chronic kidney disease (CKD). We designed this study to assess the prevalence of risk behaviors among teens with CKD in the United States and to investigate any associations between risk behavior and patient or disease characteristics. Methods After informed consent, adolescents with CKD completed an anonymous, confidential, electronic web-based questionnaire to measure risk behaviors within five domains: sex, teen driving, alcohol and tobacco consumption, illicit drug use, and depression-related risk behavior. The reference group was composed of age-, gender-, and race-matched US high school students. Results When compared with controls, teens with CKD showed significantly lower prevalence of risk behaviors, except for similar use of alcohol or illicit substances during sex (22.5% vs. 20.8%, p=0.71), feeling depressed for ≥2 weeks (24.3% vs. 29.1%, p=0.07), and suicide attempt resulting in injury needing medical attention (36.4% vs. 32.5%, p=0.78). Furthermore, the CKD group had low risk perception of cigarettes (28%), alcohol (34%), marijuana (50%), and illicit prescription drug (28%). Use of two or more substances was significantly associated with depression and suicidal attempts (p < 0.05) among teens with CKD. Conclusions Teens with CKD showed significantly lower prevalence of risk behaviors than controls. Certain patient characteristics were associated with increased risk behaviors among the CKD group. These data are somewhat reassuring, but children with CKD still need routine assessment of and counselling about risk behaviors.

Acute kidney injury (AKI) affects roughly one-quarter of children in the Intensive Care Unit and is associated with increased morbidity and mortality. Progress made in classifying paediatric AKI has allowed for better recognition of this entity. Consideration of degree of fluid overload and other risk factors for mortality should influence the choice to initiate renal replacement therapy. And while not all patients with AKI will require renal replacement therapy, the modality needs to be chosen carefully. This book chapter aims to describe AKI, provide a brief overview of the aetiology and diagnosis of this process, describe biomarkers under study for diagnosing AKI, compare the modalities of renal replacement therapy, and touch upon prognostic factors and recent advances in the field.