Whole-exome sequencing reveals novel USP9X variant in female fetus with isolated agenesis of the corpus callosum.

Whole-exome sequencing in a female fetus detected a USP9X variant. This X-linked gene was recently associated with intellectual disability and distinct pattern of malformation in females. Isolated agenesis of the corpus callosum has not been reported in association with USP9X. Identifying this variant impacted management of the subsequent pregnancy.

2,3,7,8-tetrachlorodibenzo-p-dioxin slows the progression of experimental cutaneous Leishmaniasis in susceptible BALB/c and SCID mice.

In a model of experimental cutaneous leishmaniasis, pre-exposure of Leishmania major-resistant mice to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), an aryl hydrocarbon receptor agonist, causes suppression of the protective anti-parasite T helper 1 response while paradoxically also reducing parasite burdens in those animals. In this study, we examined if TCDD exposure could also reduce parasite burdens in L. major-susceptible BALB/c mice. In the highest dose group (160 µg/Kg), TCDD treatment caused a significant reduction of parasite burdens by 10-fold after three weeks while also causing a significant lymphoid atrophy indicating suppression of the non-protective T helper 2 response. A dose-dependent delay of foot lesion progression was also observed such that lesion size in the highest dose group was less than half that of controls after 35 days of infection. Importantly, although TCDD exposure initially reduced disease severity and prolonged the course of disease by as much as three fold in some animals, this effect was transitory and TCDD did not induce resistance to L. major infection. Because TCDD exposure reduced L. major burdens in both resistant and susceptible mice, we hypothesized that TCDD reduces L. major burdens in mice by a mechanism that does not involve adaptive immunity. To test this, severe combined immunodeficient (SCID) mice were used. In mice infected with a moderate number of L. major (10,000), TCDD treatment caused a time- and dose-dependent decrease of parasite burdens by nearly 100-fold after six weeks in the highest dose group (200 µg/Kg). A significant and dose-dependent delay of foot lesion progression was also observed in these animals. These results indicate that TCDD exposure can reduce the severity of leishmanial disease in mice independent of adaptive immunity.