Identification of potential genetic risk factors for bipolar disorder by whole-exome sequencing.

This study aims at assessing the burden of rare (minor allele frequency < 1%) predicted damaging variants in the whole exome of 92 bipolar I disorder (BD) patients and 1051 controls of French ancestry. Patients exhibiting an extreme phenotype (earlier onset and family history of mood disorder) were preferentially included to increase the power to detect an association. A collapsing strategy was used to test the overall burden of rare variants in cases versus controls at the gene level. Only protein-truncating and predicted damaging missense variants were included in the analysis. Thirteen genes exhibited p values exceeding 10-3 and could be considered as potential risk factors for BD. Furthermore, the validity of the association was supported when the Exome Aggregation Consortium database non-Finnish European population was used as controls for eight of them. Their gene products are involved in various cerebral processes, some of which were previously implicated in BD and belong to pathways implicated in the therapeutic effect of lithium, the main mood stabilizer. However, exome-wide threshold for association study was not reached, emphasizing that larger samples are needed.

A manic episode with psychotic features improved by methylprednisolone in a patient with multiple sclerosis.

Several studies have reported a higher prevalence of unipolar depression and bipolar disorder among patients with multiple sclerosis (MS). However, only a few studies have reported manic episodes concomitant with new lesions enhanced by gadolinium on brain magnetic resonance imaging (MRI). Here we report the case of a 47-year-old woman suffering from MS admitted for a manic episode with psychotic features. Brain MRI revealed three new T2 lesions enhanced by gadolinium located in the corpus callosum and in ventromedial prefrontal regions. She rapidly recovered with intravenous methylprednisolone in combination with risperidone. In conclusion, in this patient, the fact that gadolinium-enhancing lesion coincided with new symptoms which responded quickly to corticosteroids suggests that the manic episode was an acute manifestation of MS.