Sahil Tembulkar

A novel de novo mutation in ATP1A3 and childhood-onset schizophrenia

We describe a child with onset of command auditory hallucinations and behavioral regression at 6 yr of age in the context of longer standing selective mutism, aggression, and mild motor delays. His genetic evaluation included chromosomal microarray analysis and whole-exome sequencing. Sequencing revealed a previously unreported heterozygous de novo mutation c.385G>A in ATP1A3, predicted to result in a p.V129M amino acid change. This gene codes for a neuron-specific isoform of the catalytic α-subunit of the ATP-dependent transmembrane sodium–potassium pump. Heterozygous mutations in this gene have been reported as causing both sporadic and inherited forms of alternating hemiplegia of childhood and rapid-onset dystonia parkinsonism. We discuss the literature on phenotypes associated with known variants in ATP1A3, examine past functional studies of the role of ATP1A3 in neuronal function, and describe a novel clinical presentation associated with mutation of this gene.

Early auditory processing evoked potentials (N100) show a continuum of blunting from clinical high risk to psychosis in a pediatric sample

BACKGROUND The N100 is a negative deflection in the surface EEG approximately 100 ms after an auditory signal. It has been shown to be reduced in individuals with schizophrenia and those at clinical high risk (CHR). N100 blunting may index neural network dysfunction underlying psychotic symptoms. This phenomenon has received little attention in pediatric populations. METHOD This cross-sectional study compared the N100 response measured via the average EEG response at the left medial frontal position FC1 to 150 sinusoidal tones in participants ages 5 to 17 years with a CHR syndrome (n=29), a psychotic disorder (n=22), or healthy controls (n=17). RESULTS Linear regression analyses that considered potential covariates (age, gender, handedness, family mental health history, medication usage) revealed decreasing N100 amplitude with increasing severity of psychotic symptomatology from healthy to CHR to psychotic level. CONCLUSIONS Longitudinal assessment of the N100 in CHR children who do and do not develop psychosis will inform whether it predicts transition to psychosis and if its response to treatment predicts symptom change.

Overlapping 16p13.11 deletion and gain of copies variations associated with childhood onset psychosis include genes with mechanistic implications for autism associated pathways: Two case reports.

Copy number variability at 16p13.11 has been associated with intellectual disability, autism, schizophrenia, epilepsy, and attention‐deficit hyperactivity disorder. Adolescent/adult‐ onset psychosis has been reported in a subset of these cases. Here, we report on two children with CNVs in 16p13.11 that developed psychosis before the age of 7. The genotype and neuropsychiatric abnormalities of these patients highlight several overlapping genes that have possible mechanistic relevance to pathways previously implicated in Autism Spectrum Disorders, including the mTOR signaling and the ubiquitin‐proteasome cascades. A careful screening of the 16p13.11 region is warranted in patients with childhood onset psychosis.

Suicidal behaviors in children and adolescents with psychotic disorders

Suicide is the leading cause of premature death in individuals with psychotic disorders. Risk for onset of suicidal behaviors tends to begin in adolescence, remaining high into young adulthood. The present study aims to evaluate the interplay of early onset psychosis and suicide risk by examining suicidal behaviors (ideation, planning, and attempts) in children and adolescents with psychotic disorders (PD) compared to typically developing peers (TD). Twenty five youths were recruited and were diagnostically evaluated for psychosis. We found that the PD children exhibited significantly higher levels of suicidal behaviors than TD children, even when parsed into individual at-risk behaviors.

Suicidal behaviors and their relationship with psychotic-like symptoms in children and adolescents at clinical high risk for psychosis

BACKGROUND Previous research has demonstrated elevated rates of suicide attempts and ideation in individuals with psychosis. This study investigated rates and severity of suicidal behavior in youth with and at clinical high risk for psychosis, and examined the positive, negative, and disorganized symptoms associated with suicidal behaviors among the clinical high risk group. METHODS Eighty-six youth ages 7-18 (n=21 non-clinical controls [NCC], n=40 clinical high risk [CHR], n=25 diagnosed psychotic disorder [PD]) were recruited. CHR and PD participants were identified using the Structured Interview for Prodromal Symptoms (SIPS) and Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (KSADS-PL). All participants completed the Suicide Behaviors Questionnaire-Revised (SBQ-R). RESULTS Findings indicated significantly higher levels of suicidal behavior among CHR and PD relative to NCC participants (F=7.64, p=0.001). 17.5% of CHR participants had previously attempted suicide. Dysphoric Mood and Odd Behavior or Appearance were significantly correlated with suicidal behavior severity among CHR youth. CONCLUSION Suicidal behavior was observed with greater frequency and severity in the CHR and PD groups than in the NCC group. CHR suicidal behavior severity was correlated most strongly with Dysphoric Mood and Odd Behavior or Appearance, a relationship which warrants further investigation.

N100 Repetition Suppression Indexes Neuroplastic Defects in Clinical High Risk and Psychotic Youth

Highly penetrant mutations leading to schizophrenia are enriched for genes coding for N-methyl-D-aspartate receptor signaling complex (NMDAR-SC), implicating plasticity defects in the diseases pathogenesis. The importance of plasticity in neurodevelopment implies a role for therapies that target these mechanisms in early life to prevent schizophrenia. Testing such therapies requires noninvasive methods that can assess engagement of target mechanisms. The auditory N100 is an obligatory cortical response whose amplitude decreases with tone repetition. This adaptation may index the health of plasticity mechanisms required for normal development. We exposed participants aged 5 to 17 years with psychosis (n = 22), at clinical high risk (CHR) for psychosis (n = 29), and healthy controls (n = 17) to an auditory tone repeated 450 times and measured N100 adaptation (mean amplitude during first 150 tones − mean amplitude during last 150 tones). N100 adaptation was reduced in CHR and psychosis, particularly among participants <13 years old. Initial N100 blunting partially accounted for differences. Decreased change in the N100 amplitude with tone repetition may be a useful marker of defects in neuroplastic mechanisms measurable early in life.

Social impairment and social language deficits in children and adolescents with and at risk for psychosis

INTRO One of the more debilitating functional outcomes of schizophrenia-spectrum disorders is social impairment. Previous studies have identified impaired social functioning both in the prodromal phase of psychosis and after acute symptoms abate, suggesting that social impairment represents a core deficit in psychosis not directly linked to psychotic episodes or symptom severity. To date, research in this area has focused primarily on adult populations rather than children, and has not directly assessed social language in individuals across the psychosis continuum. METHODS 81 youth ages 7-18 (N = 24 Typically Developing [TD], N = 36 Clinical High Risk [CHR], N = 21 Psychotic Disorder [PD]) were recruited. Youth participants were administered the Social Language Development Test (SLDT), and parent(s)/guardian(s) completed the Social Responsiveness Scale-II (SRS-II). RESULTS Social language ability was not associated with social impairment. PD participants performed significantly worse on the SLDT than TD participants. CHR and PD participants were both rated as having experienced significantly greater social impairment than TD participants on every subscale of the SRS-II. DISCUSSION Deficits in social language ability and social functioning are strong candidates for phenotypic markers of psychosis, and may be evident earlier in development than previous work has demonstrated. Additionally, the severity of social impairment did not differ between CHR and PD participants, further supporting that social cognitive deficits and social impairment, while related to symptom severity, are discrete deficits in individuals with and at risk for psychosis. These results highlight the importance of addressing social skills for individuals presenting in clinical settings with psychotic symptoms, including children.

De novo ATP1A3 and compound heterozygous NLRP3 mutations in a child with autism spectrum disorder, episodic fatigue and somnolence, and muckle-wells syndrome

Complex phenotypes may represent novel syndromes that are the composite interaction of several genetic and environmental factors. We describe an 9-year old male with high functioning autism spectrum disorder and Muckle-Wells syndrome who at age 5  years of age manifested perseverations that interfered with his functioning at home and at school. After age 6, he developed intermittent episodes of fatigue and somnolence lasting from hours to weeks that evolved over the course of months to more chronic hypersomnia. Whole exome sequencing showed three mutations in genes potentially involved in his clinical phenotype. The patient has a predicted pathogenic de novo heterozygous p.Ala681Thr mutation in the ATP1A3 gene (chr19:42480621C>T, GRCh37/hg19). Mutations in this gene are known to cause Alternating Hemiplegia of Childhood, Rapid Onset Dystonia Parkinsonism, and CAPOS syndrome, sometimes accompanied by autistic features. The patient also has compound heterozygosity for p.Arg490Lys/p.Val200Met mutations in the NLRP3 gene (chr1:247588214G>A and chr1:247587343G>A, respectively). NLRP3 mutations are associated in an autosomal dominant manner with clinically overlapping auto-inflammatory conditions including Muckle-Wells syndrome. The p.Arg490Lys is a known pathogenic mutation inherited from the patients father. The p.Val200Met mutation, inherited from his mother, is a variant of unknown significance (VUS). Whether the de novoATP1A3mutation is responsible for or plays a role in the patients episodes of fatigue and somnolence remains to be determined. The unprecedented combination of two NLRP3 mutations may be responsible for other aspects of his complex phenotype.

Potentially traumatic events in youth with and at clinical high risk for psychosis

Previous research has demonstrated a strong association between early trauma exposure and the development of psychotic symptoms. However, few of these studies have included young adolescents and children. This study investigated rates and number of potentially traumatic experiences (PTEs) among typically developing youth (TD; n = 21), youth at clinical high risk for psychosis (CHR; n = 38), and youth with a psychotic disorder (PD; n = 28) between 7 and 18 years of age. CHR participants were further evaluated to determine whether a history of PTEs was associated with prodromal symptom severity.