17q12 Recurrent Deletion Syndrome in Childhood

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.

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.

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.

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.