An unusual, small cell-predominant, high-grade glioneuronal tumor in the occipital lobe of a 49-year-old man that co-existed with a low-grade tumor is reported. The tumor consisted of two distinct com Show more
An unusual, small cell-predominant, high-grade glioneuronal tumor in the occipital lobe of a 49-year-old man that co-existed with a low-grade tumor is reported. The tumor consisted of two distinct components: the major component was a dense proliferation of primitive small cells showing bidirectional neuronal and glial differentiation; and the minor component consisted of a proliferation of well-differentiated astrocytes intermingled with mature neuronal cells. In the former component, perivascular pseudorosette-like or pseudopapillary growth reminiscent of ependymoma or papillary glioneuronal tumor (PGNT), respectively, was prominent, and hypertrophic astrocytic cells were located just outside the central blood vessels. Small cells were immunoreactive for Olig2, synaptophysin, and, less frequently, for glial fibrillary acidic protein. The low-grade component included Rosenthal fibers, hemosiderin deposition, and perivascular lymphocytic infiltration, thus closely resembling ganglioglioma. Cytogenetic studies did not demonstrate any mutations or rearrangements of the genes Show less
Carbamoylphosphate synthetase I deficiency (CPS1D) is a urea-cycle disorder characterized by episodes of life-threatening hyperammonemia. Correct diagnosis is crucial for patient management, but is di Show more
Carbamoylphosphate synthetase I deficiency (CPS1D) is a urea-cycle disorder characterized by episodes of life-threatening hyperammonemia. Correct diagnosis is crucial for patient management, but is difficult to make from clinical presentation and conventional laboratory tests alone. Enzymatic or genetic diagnoses have also been hampered by difficult access to the appropriate organ and the large size of the gene (38 exons). In this study, in order to address this diagnostic dilemma, we performed the largest mutational and clinical analyses of this disorder to date in Japan. Mutations in CPS1 were identified in 16 of 18 patients with a clinical diagnosis of CPS1D. In total, 25 different mutations were identified, of which 19 were novel. Interestingly, in contrast to previous reports suggesting an extremely diverse mutational spectrum, 31.8% of the mutations identified in Japanese were common to more than one family. We also identified two common polymorphisms that might be useful for simple linkage analysis in prenatal diagnosis. The accumulated clinical data will also help to reveal the clinical presentation of this rare disorder in Japan. Show less