Background: Bronchiolitis is the most common cause of lower respiratory tract infection (LRTI) in the first year of life. We analyzed the association between complete blood count (CBC), c-reactive protein (CRP), and novel inflammatory indexes (NLR, PLR, MLR, ELR, LMR, NPR, LPR, LNR, PNR, SII, SIRI) in predicting bronchiolitis severity at hospital admission. Methods: We retrospectively collected data from 95 infants hospitalized for bronchiolitis in a third-level hospital during three epidemic seasons. Five outcomes of severity were analyzed: BRAS; pediatric intensive care unit (PICU) admission; ventilatory support; intravenous (IV) rehydration; and length of stay (LOS). Results: Lower age and weight at admission were statistically associated with four of the five severity outcomes. Prolonged LOS (≥6 days) was associated with high values of total white blood cells, lymphocytes, and eosinophils. Only three inflammatory indexes (PLR, MLR, and PNR) showed a significant association with one outcome (prolonged LOS). A new index (RBC/AiW/1000) was statistically associated with each severity outcome for a value > 350. Conclusions: We proposed a comprehensive analysis of the association between CBC, CRP, and novel inflammatory indexes and bronchiolitis severity. RBC/AiW/1000 could represent a future predictive marker of disease severity at hospital admission in infants with bronchiolitis.

Background: The 17q12 recurrent deletion syndrome is a genomic disorder encompassing a 1.4 to 1.5 Mb region that includes the HNF1B gene, and it manifests with remarkable phenotypic variability. Renal anomalies, endocrine and metabolic disturbances, and neurodevelopmental or psychiatric disorders are recurrent features, although penetrance and severity differ widely between patients. Methods: We reviewed the literature on the molecular basis, clinical presentation, diagnostic approaches, and management of 17q12 deletion syndrome, and we illustrate the variability of this condition through two contrasting paediatric cases. Results: The cases concern three siblings harbouring the same familial deletion, who nevertheless exhibited striking intrafamilial variability, ranging from renal and neurodevelopmental features to multisystemic involvement. These cases exemplify both extremes of the syndrome and highlight the challenges of clinical prognostication. Conclusions: The review and cases emphasise the importance of early genetic testing in paediatric renal anomalies, the necessity of multidisciplinary surveillance even in asymptomatic individuals, and the relevance of 17q12 deletion as a model of variable expressivity in genomic medicine.