Biallelic variants in SLC38A3 encoding a glutamine transporter cause epileptic encephalopathy

The solute carrier (SLC) superfamily encompasses >400 transmembrane transporters involved in the exchange of amino acids, nutrients, ions, metals, neurotransmitters and metabolites across biological membranes. SLCs are highly expressed in the mammalian brain; defects in nearly 100 unique SLC-encoding genes (OMIM: https://www.omim.org) are associated with rare Mendelian disorders including developmental and epileptic encephalopathy (DEE) and severe neurodevelopmental disorders (NDDs). Exome sequencing and family-based rare variant analyses on a cohort with NDD identified two siblings with DEE and a shared deleterious homozygous splicing variant in SLC38A3. The gene encodes SNAT3, a sodium-coupled neutral amino acid transporter and a principal transporter of the amino acids asparagine, histidine, and glutamine, the latter being the precursor for the neurotransmitters GABA and glutamate. Additional subjects with a similar DEE phenotype and biallelic predicted-damaging SLC38A3 variants were ascertained through GeneMatcher and collaborations with research and clinical molecular diagnostic laboratories. Untargeted metabolomic analysis was performed to identify novel metabolic biomarkers. Ten individuals from seven unrelated families from six different countries with deleterious biallelic variants in SLC38A3 were identified. Global developmental delay, intellectual disability, hypotonia, and absent speech were common features while microcephaly, epilepsy, and visual impairment were present in the majority. Epilepsy was drug-resistant in half. Metabolomic analysis revealed perturbations of glutamate, histidine, and nitrogen metabolism in plasma, urine, and cerebrospinal fluid of selected subjects, potentially representing biomarkers of disease. Our data support the contention that SLC38A3 is a novel disease gene for DEE and illuminate the likely pathophysiology of the disease as perturbations in glutamine homeostasis

Feeling labeled, judged, lectured, and rejected by family and friends over depression: Cautionary results for primary care clinicians from a multi-centered, qualitative study

<p>Abstract</p> <p>Background</p> <p>Family and friends may help patients seek out and engage in depression care. However, patients’ social networks can also undermine depression treatment and recovery. In an effort to improve depression care in primary care settings, we sought to identify, categorize, and alert primary care clinicians to depression-related messages that patients hear from friends and family that patients perceive as unhelpful or detrimental.</p> <p>Methods</p> <p>We conducted 15 focus groups in 3 cities. Participants (n = 116) with a personal history or knowledge of depression responded to open-ended questions about depression, including self-perceived barriers to care-seeking. Focus group conversations were audio-recorded and analyzed using iterative qualitative analysis.</p> <p>Results</p> <p>Four themes emerged related to negatively-received depression messages delivered by family and friends. Specifically, participants perceived these messages as making them feel labeled, judged, lectured to, and rejected by family and friends when discussing depression. Some participants also expressed their interpretation of their families’ motivations for delivering the messages and described how hearing these messages affected depression care.</p> <p>Conclusions</p> <p>The richness of our results reflects the complexity of communication within depression sufferers’ social networks around this stigmatized issue. To leverage patients’ social support networks effectively in depression care, primary care clinicians should be aware of both the potentially beneficial and detrimental aspects of social support. Specifically, clinicians should consider using open-ended queries into patients’ experiences with discussing depression with family and friends as an initial step in the process. An open-ended approach may avoid future emotional trauma or stigmatization and assist patients in overcoming self-imposed barriers to depression discussion, symptom disclosure, treatment adherence and follow-up care.</p