Paediatric Acute onset Neuropsychiatric Syndrome: Exploratory study finds no evidence of HLA class II association but high rate of autoimmunity in first-degree relatives

Factors Associated with Symptom Persistence in PANS: Part II-Presenting Features, Medical Comorbidities, and IVIG Treatment History

Objective: Individuals with Pediatric Acute Onset Neuropsychiatric Syndrome (PANS) experience neuropsychiatric symptoms following an infection or other trigger. Although PANS is typically described as relapsing-remitting, a large community-based 2017 study revealed a range of courses. The present study examined clinical predictors of symptom persistence, measured as % days symptom-free, in this same sample. Methods: A 146-question online survey gathered histories (infections and other triggers, medical and developmental comorbidities), symptomatology, interventions, and outcomes (including school functioning) of PANS patients. Multivariate analyses were applied to examine associations between these variables and % days symptom-free across the disease course. Results: Among the 646 subjects included, significant relationships were found between greater symptom persistence and higher rates of medical comorbidities (especially rashes, headaches, chronic sinusitis, frequent diarrhea, and immune deficiencies), developmental diagnoses, and respondent-perceived developmental lags. Subjects with greater symptom persistence were significantly more likely to report PANS exacerbations associated with infections in close contacts, vaccinations, environmental triggers, and exacerbations of comorbidities and were more likely to report PANS recurrences triggered by Epstein Barr Virus, mycoplasma, and sinus infections. More persistent PANS was also associated with significantly higher frequencies of certain symptoms (sleep disturbance, urinary incontinence, muscle pain, brain fog, sensory defensiveness, irritability, and aggression-related symptoms), less effectiveness of intravenous immunoglobulin in combating symptoms, and more difficulty attending school. Conclusions: Our results suggest high symptom persistence in PANS to be associated with more pervasive medical and neuropsychiatric symptoms. Differences in symptom persistence are associated with both intrinsic (e.g., immune competence) and extrinsic (e.g., infections, treatment) factors. Because extrinsic factors are potentially modifiable, it is critical that providers be aware of current guidelines on PANS evaluation and treatment.

Identification of ultra-rare genetic variants in pediatric acute onset neuropsychiatric syndrome (PANS) by exome and whole genome sequencing

Abrupt onset of severe neuropsychiatric symptoms including obsessive-compulsive disorder, tics, anxiety, mood swings, irritability, and restricted eating is described in children with Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS). Symptom onset is often temporally associated with infections, suggesting an underlying autoimmune/autoinflammatory etiology, although direct evidence is often lacking. The pathological mechanisms are likely heterogeneous, but we hypothesize convergence on one or more biological pathways. Consequently, we conducted whole exome sequencing (WES) on a U.S. cohort of 386 cases, and whole genome sequencing (WGS) on ten cases from the European Union who were selected because of severe PANS. We focused on identifying potentially deleterious genetic variants that were de novo or ultra-rare (MAF) < 0.001. Candidate mutations were found in 11 genes (PPM1D, SGCE, PLCG2, NLRC4, CACNA1B, SHANK3, CHK2, GRIN2A, RAG1, GABRG2, and SYNGAP1) in 21 cases, which included two or more unrelated subjects with ultra-rare variants in four genes. These genes converge into two broad functional categories. One regulates peripheral immune responses and microglia (PPM1D, CHK2, NLRC4, RAG1, PLCG2). The other is expressed primarily at neuronal synapses (SHANK3, SYNGAP1, GRIN2A, GABRG2, CACNA1B, SGCE). Mutations in these neuronal genes are also described in autism spectrum disorder and myoclonus-dystonia. In fact, 12/21 cases developed PANS superimposed on a preexisting neurodevelopmental disorder. Genes in both categories are also highly expressed in the enteric nervous system and the choroid plexus. Thus, genetic variation in PANS candidate genes may function by disrupting peripheral and central immune functions, neurotransmission, and/or the blood-CSF/brain barriers following stressors such as infection.

Patient-Driven Findings of Genetic Associations for PANS and PANDAS

Background: There are presently very few genetic studies for PANS (Pediatric Acute-Onset Neuropsychiatric Syndrome) or PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections). More work in genetic associations for PANS and PANDAS (P/P) is needed to increase understanding of these debilitating childhood disorders that have a range of presentations.Objective: This work represents a novel approach that aims to determine genetic associations between P/P and other diseases, disorders and traits (hereafter referred to as phenotypes).Methods: Consumer genetic data (23andMe, AncestryDNA) for 155 patients with P/P were obtained from consenting parents over a period from 2018 to 2020. An analysis plan for this work was registered at Open Science Framework, additional genotypes imputed using Impute.me, and polygenic risk scores for 1,702 phenotypes calculated for each of the 155 P/P patients.Results: One-sample t-tests performed across the 155 individual risk scores revealed that P/P is statistically significantly associated with 21 different groups of Single Nucleotide Polymorphisms (SNPs) that are in turn associated with 21 phenotypes. Some of the 21 phenotypes (see Table 3) are previously known to be related to or associated with P/P: a group of SNPs associated with Tourette’s Syndrome, and another group associated with Autism Spectrum Disorder or Schizophrenia, and a third associated with “feeling nervous” yielded t-tests with p values of 1.2x10-5, 1.2x10-11 and 1.0x10-5 respectively for association with the P/P data. This validated our analysis methodology. Our analysis also revealed novel genetic associations such as between P/P and plasma anti-thyroglobulin levels (p=1.3x10-7), between P/P and triglycerides (p=5.6x10-6), and between P/P and Lewy body disease (p=7.8x10-6), inviting further investigation into the underlying etiology of P/P.Conclusion: P/P is associated with many phenotypes not previously recognized as being connected to P/P. Further work on these connections can lead to better understanding of P/P.