Novel sonic hedgehog gene variant in a patient with hyponatremia, microsomia, and midline defects; phenotype description in association with a variant of unknown significance [c.755_757del p.(Phe252del)] and an approach to salt-wasting in SHH-related adrenal disorders.

OBJECTIVES: To contribute a novel sonic hedgehog (SHH) gene variant in association with a novel-meagerly described phenotype and discuss SHH signaling pathway pathology. CASE PRESENTATION: We present a 5-year-old boy with excessive hyponatremia and natriuresis, microform holoprosencephaly and microsomia, with morphologically intact hypothalamic-pituitary-adrenal (HPA) axis, and hypoaldosteronism, yet without hyperreninemia, hyperkalemia, dehydration episodes, or glucocorticoid insufficiency. Extensive workup excluded common causes of salt-wasting and revealed a novel variant of unknown significance on the sonic hedgehog (SHH) gene; NM_000193.4:c.755_757del (p.Phe252del), in heterozygosity. CONCLUSIONS: Salt-wasting in children is predominantly caused by central nervous system lesions, renal tubular dysfunction, or adrenal insufficiency. The SHH protein is a signaling molecule, essential in embryogenesis-including HPA axis differentiation. Inactivating SHH variants disrupt the signaling pathway, leading to dysplasia or dysfunction of target organs. What's new: • We analyze the patient's phenotype in the light of this novel variant • Patient's isolated aldosterone deficiency possibly implies a selective signaling defect affecting the development of adrenal zona glomerulosa • Unexplained hyporeninemia and hypokalemia in the context of hypoaldosteronism raise questions on SHH signaling pathophysiology.

Herpes Zoster Ophthalmicus in a Healthy Toddler Fully Immunized Against Varicella-Zoster Virus: A Case Report and Review of Treatment Strategies in Children.

Herpes zoster ophthalmicus (HZO) is a rare presentation of herpes zoster in children; however, it may become chronic and debilitating. The pathophysiology of HZO complications is not completely understood and may include virus virulence, vascular and neural inflammation and immune reactivity. Therefore, clinical experts suggest an antiviral agent combined with topical steroids, but treatment duration and the need for secondary prophylaxis, given the likelihood of recurrence, are not clearly defined. We present a complex case of HZO in a varicella zoster virus (VZV)-vaccinated toddler successfully treated with acyclovir and topical steroids. We also present a review of the relevant literature regarding the therapeutic management and long-term sequelae of HZO in children.

A toddler diagnosed with severe postinfectious bronchiolitis obliterans and COVID-19 infection.

During the COVID-19 pandemic, management of SARS-CoV-2 infection in children with underlying chronic lung disease has been challenging. There are limited studies in children with respiratory comorbidities, apart from asthma, presumably due to low morbidity of SARS-CoV-2 infection in the general pediatric population along with the low incidence of certain pulmonary conditions. Compassionate use of remdesivir has been shown to reduce time to clinical improvement in adults and has been retrospectively studied in small pediatric cohorts with promising results. Whether children with underlying respiratory conditions may benefit from antiviral treatment in the context of different pathophysiologic backgrounds and unknown drug safety and efficacy needs to be further evaluated. We present a case of COVID-19 infection in a 3-year old toddler with severe postinfectious bronchiolitis obliterans, who received compassionate treatment with 5-day-course of remdesivir, and recovered with favourable outcome.