An unusual cause of fetal hypomobility:congenital central hypoventilation syndrome associated with hirschsprung disease.

Co-occurrence of congenital central hypoventilation syndrome and Hirschsprung disease is known as Haddad syndrome. Affected patients develop with variable expressivity a dysfunction of the autonomic nervous system. We report the natural history of a full-term newborn infant presenting multiple features of autonomic system dysfunction that were already noted antenatally. The presence of a nonpolyalanine repeat expansion mutation in the PHOX2B gene confirmed postnatally the diagnosis of Haddad syndrome. This case suggests that patients presenting with autonomic system dysfunction may already present signs of the disease during the fetal period. Furthermore, antenatal presentations may correlate with a more severe presentation of the disease. In conclusion, antenatal signs of dysautonomy should stimulate multidisciplinary prenatal approach to orientate proper postnatal intervention and facilitate treatment strategies.

Hypoxic-preconditioning enhances the regenerative capacity of neural stem/progenitors in subventricular zone of newborn piglet brain.

Perinatal hypoxia-ischemia (HI) results in brain injury, whereas mild hypoxic episodes result in preconditioning, which can significantly reduce the vulnerability of the brain to subsequent severe hypoxia-ischemia. Hypoxic-preconditioning (PC) has been shown to enhance cell survival and differentiation of progenitor cells in the central nervous system (CNS). The purpose of this study was to determine whether pretreatment with PC prior to HI stimulates subventricular zone (SVZ) proliferation and neurogenesis in newborn piglets. One-day-old piglets were subjected to PC (8% O2/92% N2) for 3h and 24h later were exposed to HI produced by combination of hypoxia (5% FiO2) for a pre-defined period of 30min and ischemia induced by a period of 10min of hypotension. Here we demonstrate that SVZ derived neural stem/progenitor cells (NSPs) from PC, HI and PC+HI piglets proliferated as neurospheres, expressed neural progenitor and neurodevelopmental markers, and that greater proportion of the spheres generated are multipotential. Neurosphere assay revealed that preconditioning pretreatment increased the number of NSP-derived neurospheres in SVZ following HI compared to normoxic and HI controls. NSPs from preconditioned SVZ generated twice as many neurons and astrocytes in vitro. Injections with 5-Bromo-2-deoxyuridine (BrdU) after PC revealed a robust proliferative response within the SVZ that continued for one week. PC also increased neurogenesis in vivo, doublecortin positive cells with migratory profiles were observed streaming from the SVZ to striatum and neocortex. These findings show that the induction of proliferation and neurogenesis by PC might be a positive adaptation for an efficient repair and plasticity in the event of a hypoxic-ischemic insult.