Mutations in STAMBP, encoding a deubiquitinating enzyme, cause microcephaly-capillary malformation syndrome

Microcephaly–capillary malformation (MIC-CAP) syndrome is characterized by severe microcephaly with progressive cortical atrophy, intractable epilepsy, profound developmental delay and multiple small capillary malformations on the skin. We used whole-exome sequencing of five patients with MIC-CAP syndrome and identified recessive mutations in STAMBP, a gene encoding the deubiquitinating (DUB) isopeptidase STAMBP (STAM-binding protein, also known as AMSH, associated molecule with the SH3 domain of STAM) that has a key role in cell surface receptor–mediated endocytosis and sorting. Patient cell lines showed reduced STAMBP expression associated with accumulation of ubiquitin-conjugated protein aggregates, elevated apoptosis and insensitive activation of the RAS-MAPK and PI3K-AKT-mTOR pathways. The latter cellular phenotype is notable considering the established connection between these pathways and their association with vascular and capillary malformations. Furthermore, our findings of a congenital human disorder caused by a defective DUB protein that functions in endocytosis implicates ubiquitin-conjugate aggregation and elevated apoptosis as factors potentially influencing the progressive neuronal loss underlying MIC-CAP syndrome

A Mild PUM1 Mutation Is Associated with Adult-Onset Ataxia, whereas Haploinsufficiency Causes Developmental Delay and Seizures

© 2018 Elsevier Inc. Certain mutations can cause proteins to accumulate in neurons, leading to neurodegeneration. We recently showed, however, that upregulation of a wild-type protein, Ataxin1, caused by haploinsufficiency of its repressor, the RNA-binding protein Pumilio1 (PUM1), also causes neurodegeneration in mice. We therefore searched for human patients with PUM1 mutations. We identified eleven individuals with either PUM1 deletions or de novo missense variants who suffer a developmental syndrome (Pumilio1-associated developmental disability, ataxia, and seizure; PADDAS). We also identified a milder missense mutation in a family with adult-onset ataxia with incomplete penetrance (Pumilio1-related cerebellar ataxia, PRCA). Studies in patient-derived cells revealed that the missense mutations reduced PUM1 protein levels by ∼25% in the adult-onset cases and by ∼50% in the infantile-onset cases; levels of known PUM1 targets increased accordingly. Changes in protein levels thus track with phenotypic severity, and identifying posttranscriptional modulators of protein expression should identify new candidate disease genes. Different dosages of an RNA-binding protein result in human neurological diseases of corresponding severities

Family Experiences Prior to the Initiation of Care for First-Episode Psychosis: A Meta-Synthesis of Qualitative Studies

Objectives: This study systematically reviewed existing qualitative evidence of family members’ experiences prior to the initiation of mental health services for a loved one experiencing their first episode of psychosis (FEP). Methods: A meta-synthesis review of published peer-reviewed qualitative studies conducted between 2010 and 2019 were included. Keyword searches were performed in four electronic databases and the reference lists of primary manuscripts. Two independent reviewers used the Critical Appraisal Skills Programme (CASP) qualitative checklist to assess methodological quality of each study. Results: A total of 365 articles were initially identified and 9 were articles identified in a secondary review and literature search. A total of 21 met inclusion criteria. Of those included in this review 169, mothers were the primary family to recall experiences. The meta-synthesis identified four major themes related to family member experiences prior to the initiation of mental health services for FEP: the misinterpretation of signs, the emotional impact of FEP on family members, the effect of stigma on family members, and engaging with resources prior to mental health services for FEP. Conclusions: Additional research is needed to develop healthy communication strategies that effectively deliver educational information about psychosis. This meta-synthesis also identified the need to understand help-seeking behaviors among families of those with FEP in effort to reduce the duration of untreated psychosis and improve pathways to care often initiated by a family member