Despite appropriate antibiotic therapy, lateral sinus thrombosis and other intracranial complications of otitis media are still a threat to children in the modern era. Neurologic, rather than otologic, symptoms may dominate the presentation of otogenic lateral sinus thrombosis. Thus, a high index of suspicion may be critical for ensuring timely diagnosis of this rare condition.

A combined craniofacial approach is appropriate for juvenile nasopharyngeal angiofibroma that extends intracranially. Complete tumor removal with acceptable morbidity can be expected.

Alagille syndrome (AGS) is a heterogeneous developmental disorder associated with bile duct paucity and various organ anomalies. The syndrome is caused by mutations in JAG1, which encodes a ligand in the Notch signaling pathway, in the majority of cases and mutations in the NOTCH2 receptor gene in less than 1% of patients. Although a wide array of JAG1 mutations have been identified in the AGS population, these mutational variants have not accounted for the wide phenotypic variability observed in patients with this syndrome. The Fringe genes encode glycosyltransferases, which modify Notch and alter ligand-receptor affinity. In this study, we analyzed double heterozygous mouse models to examine the Fringe genes as potential modifiers of the Notchmediated hepatic phenotype observed in AGS. We generated mice that were haploinsufficient for both Jag1 and one of three paralogous Fringe genes: Lunatic (Lfng), Radical (Rfng), and Manic (Mfng). Adult Jag1 ؉/؊ Lfng ؉/؊ and Jag1 ؉/؊ Rfng ؉/؊ mouse livers exhibited widespread bile duct proliferation beginning at 5 weeks of age and persisting up to 1 year. The Jag1 ؉/؊ Mfng ؉/؊ livers showed a subtle, yet significant increase in bile duct numbers and bile duct to portal tract ratios. These abnormalities were not observed in the newborn period. Despite the portal tract expansion by bile ducts, fibrosis was not increased and epithelial to mesenchymal transition was not shown in the affected portal tracts. Conclusion: Mice heterozygous for mutations in Jag1 and the Fringe genes display striking bile duct proliferation, which is not apparent at birth. These findings suggest that the Fringe genes may regulate postnatal bile duct growth and remodeling, and serve as candidate modifiers of the hepatic phenotype in AGS.

Objectives In this retrospective study, we aimed to determine the incidence and distribution of fractures in patients with Alagille syndrome, one of the leading inherited causes of pediatric cholestatic liver disease. Methods Surveys regarding growth, nutrition, and organ involvement were distributed to patient families in the Alagille Syndrome Alliance or The Children’s Hospital of Philadelphia research database. Patients with a history of fracture were identified by their response to one question, and details characterizing each patient’s medical, growth, and fracture history were obtained through chart review and telephone contact. Results Twelve of 42 patients (28%) reported a total of 27 fractures. Patients experienced fractures at a mean age of 5 years, which contrasts with healthy children, in whom fracture incidence peaks in adolescence. Fractures occurred primarily in the lower extremity long bones (70%) and with little or no trauma (84%). Estimated incidence rate calculations yielded 399.6 total fractures/10,000 person years (95% CI = 206.5, 698.0) and 127.6 femur fractures/10,000 person-years (95% CI = 42.4, 297.7). There were no differences in gender, age distribution or organ system involvement between the fracture and no-fracture groups. Conclusions Children with Alagille syndrome may be at risk for pathologic fractures, which manifest at an early age and in a unique distribution favoring the lower extremity long bones. While this preliminary study is limited by small sample size and potential ascertainment bias, the data suggest that larger studies are warranted to further characterize fracture risk and to explore factors contributing to bone fragility in these children.

Loss-of-function mutations in the Notch ligand, Jagged1 (Jag1), result in multi-system developmental pathologies associated with Alagille syndrome (ALGS). ALGS patients present with skeletal manifestations including hemi-vertebrae, reduced bone mass, increased fracture incidence and poor bone healing. However, it is not known whether the increased fracture risk is due to altered bone homeostasis (primary) or nutritional malabsorption due to chronic liver disease (secondary). To determine the significance of Jag1 loss in bone, we characterized the skeletal phenotype of two Jag1-floxed conditional knockout mouse models: Prx1-Cre;Jag1f/f to target osteoprogenitor cells and their progeny, and Col2.3-Cre;Jag1f/f to target mid-stage osteoblasts and their progeny. Knockout phenotypes were compared to wild-type (WT) controls using quantitative microcomputed tomography, gene expression profiling and mechanical testing. Expression of Jag1 and the Notch target genes Hes1 and Hey1 was downregulated in all Jag1 knockout mice. Osteoblast differentiation genes were downregulated in whole bone of both groups, but unchanged in Prx1-Cre;Jag1f/f cortical bone. Both knockout lines exhibited changes in femoral trabecular morphology including decreased bone volume fraction and increased trabecular spacing, with males presenting a more severe trabecular osteopenic phenotype. Prx1-Cre;Jag1f/f mice showed an increase in marrow mesenchymal progenitor cell number and, counterintuitively, developed increased cortical thickness resulting from periosteal expansion, translating to greater mechanical stiffness and strength. Similar alterations in femoral morphology were observed in mice with canonical Notch signaling disrupted using Prx1-Cre-regulatable dominant-negative mastermind like-protein (dnMAML). Taken together, we report that 1) Jag1 negatively regulates the marrow osteochondral progenitor pool, 2) Jag1 is required for normal trabecular bone formation and 3) Notch signaling through homotypic Jag1 signaling in osteochondral progenitors, but not mature osteoblasts, inhibits periosteal expansion. Therefore, Jag1 signaling within the osteoblast lineage regulates bone metabolism in a compartment-dependent manner. Moreover, loss of Jag1 function in osteoblast lineage cells may contribute to the skeletal phenotype associated with ALGS.