A microdeletion at 12q24.31 can mimic beckwith-wiedemann syndrome neonatally

We report on a patient who was initially suspected to have Beckwith-Wiedemann syndrome because of recurrent neonatal hypoglycaemias, macroglossia and overgrowth, but in whom no 11p15 abnormality could be found. Follow-up showed continued overgrowth and disturbed glucose homeostasis, a marked developmental delay, and severe behavioural problems especially caused by anxieties. Array comparative genomic hybridization analysis showed a de novo 12q24.31 interstitial deletion, which was confirmed by fluorescence in situ hybridization. The deleted region contains amongst others: HNF1 homeobox A (HNF1A) which is important for the regulation of gene expression in the liver and involved in maturity-onset diabetes of the young type 3 and insulin resistance; acyl-CoA dehydrogenase short chain (ACADS) which encodes an enzyme important in mitochondrial fatty acid beta-oxidation and can cause short-chain acyl-CoA dehydrogenese (SCAD) deficiency, and purinergic receptor P2X7 (P2RX7) which encodes a ligand-gated ion channel, and of which polymorphisms are found with increased frequency in patients with psychiatric disorders, especially anxieties. We conclude the present patient has a hitherto undescribed contiguous gene syndrome, which can initially resemble Beckwith-Wiedemann syndrome.