Monthly Archives:
June 2023

Evaluation of C4 gene copy number in Pediatric Acute Neuropsychiatric Syndrome

Kalinowski A, Tian L, Pattni R, Ollila H, Khan M, Manko C, Silverman M, Ma M, Columbo L, Farhadian B, Swedo S, Murphy T, Johnson M, Fernell E, Gillberg C, Thienemann M, Mellins ED, Levinson DF, Urban AE, Frankovich J. Evaluation of C4 gene copy number in Pediatric Acute Neuropsychiatric Syndrome. Dev Neurosci. 2023 Jun 28. doi: 10.1159/000531707. Epub ahead of print. PMID: 37379808.

Pediatric acute-onset neuropsychiatric syndrome (PANS) is an abrupt-onset neuropsychiatric disorder. PANS patients have an increased prevalence of comorbid autoimmune illness, most commonly arthritis. In addition, an estimated one-third of PANS patients present with low serum C4 protein, suggesting decreased production or increased consumption of C4 protein. To test the possibility that copy number (CN) variation contributes to risk of PANS illness, we compared mean total C4A and total C4B CN in ethnically matched subjects from PANS DNA samples and controls (192 cases and 182 controls). Longitudinal data from the Stanford PANS cohort (n = 121) were used to assess whether the time to juvenile idiopathic arthritis (JIA) or autoimmune disease (AI) onset was a function of total C4A or C4B CN. Lastly, we performed several hypothesis-generating analyses to explore the correlation between individual C4 gene variants, sex, specific genotypes, and age of PANS onset. Although the mean total C4A or C4B CN did not differ in PANS compared to controls, PANS patients with low C4B CN were at increased risk for subsequent JIA diagnosis (hazard ratio = 2.7, p value = 0.004). We also observed a possible increase in risk for AI in PANS patients and a possible correlation between lower C4B and PANS age of onset. An association between rheumatoid arthritis and low C4B CN has been reported previously. However, patients with PANS develop different types of JIA: enthesitis-related arthritis, spondyloarthritis, and psoriatic arthritis. This suggests that C4B plays a role that spans these arthritis types.

Cortical glutamate and GABA are related to compulsive behaviour in individuals with obsessive compulsive disorder and healthy controls

Biria, M., Banca, P., Healy, M.P. et al. Cortical glutamate and GABA are related to compulsive behaviour in individuals with obsessive compulsive disorder and healthy controls. Nat Commun 14, 3324 (2023). https://doi.org/10.1038/s41467-023-38695-z

A Cambridge neuroimaging study found that compulsive behavior is associated with glutamate–GABA imbalance, particularly elevated glutamate, across both individuals with OCD and healthy controls. Using ultra–high field MRS, the authors show that compulsivity maps to excitatory–inhibitory imbalance in brain regions involved in habit formation and control. These findings support a mechanism-based view of compulsive symptoms, while underscoring the need for caution when targeting glutamatergic systems clinically due to their broader downstream effects. The findings are particularly relevant given increasing clinical interest in glutamate-modulating medications, which are sometimes used off-label in OCD and neuroimmune conditions. At the same time, the study reinforces the need for caution: altering glutamatergic systems can have complex downstream effects, especially in conditions where dopamine and immune signaling may also be involved. This work strengthens the rationale for mechanism-focused research while underscoring why individualized, carefully monitored treatment remains essential.

Exploring the Complex Associations Between Prenatal and Early-Life Infections and Obsessive-Compulsive and Tic-Related Disorders
Hirschtritt ME, Mathews CA. Exploring the Complex Associations Between Prenatal and Early-Life Infections and Obsessive-Compulsive and Tic-Related Disorders. Biol Psychiatry. 2023 Jun 1;93(11):959-961. doi: 10.1016/j.biopsych.2023.03.003. PMID: 37197834.
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throat infection caused damage to multiple organ systems in … posited a diagnostic
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