HNF1B and Neurodevelopmental delay: In a cohort described by Clissold et al., 8 out of 20 patients with the 17q12 microdeletion (40%) exhibited NDD-related clinical manifestations, whereas none of the individuals carrying intragenic HNF1B mutations showed neuropsychiatric alterations, thereby reinforcing the hypothesis of a specific association between 17q12 deletion and neurological vulnerability [25].