The effectiveness and tolerability of pharmacotherapy for psychosis in 22q11.2 Deletion Syndrome: A systematic review

OBJECTIVE

The 22q11.2 Deletion Syndrome (22q11.2DS) is the most common microdeletion in humans with over 180 phenotypic expressions. Approximately 30-40% of affected individuals will develop psychosis and 25% meet the criteria for schizophrenia. Despite this, pharmacotherapy for managing psychosis in 22q11.2DS is poorly understood and 22q11.2DS psychosis is frequently labelled as treatment resistant. The objectives of this paper are to evaluate the effectiveness and tolerability of pharmacotherapy for 22q11.2DS psychosis and evaluate the evidence for treatment resistance.

METHOD

A systematic search was performed using CINAHL, The Cochrane Library (Cochrane Database of Systematic Reviews; Cochrane Central Register of Controlled Trials and Cochrane Clinical Answers), EMBASE, PsycINFO, PubMed, Scopus and Web of Science Core Collection from inception to December 2022. It yielded 39 case reports, 6 case series and 1 retrospective study which met the inclusion criteria.

RESULTS

Based on the current literature, individuals with 22q11.2DS psychosis experience a greater rate of medical co-morbidities such as cardiac arrhythmias, seizures and movement disorders, which complicate pharmacotherapy. Poor tolerability rather than poor clinical response motivates the switching of antipsychotics, which may explain the labelling of treatment resistance in the literature.

CONCLUSION

There are insufficient data to recommend a single antipsychotic for 22q11.2DS psychosis. Nonetheless, with proactive management of co-morbidities, antipsychotic medication in 22q11.2DS psychosis is an effective treatment commonly resulting in improvement in quality of life.

Clozapine Use in 22q11.2 Deletion Syndrome: A Systematic Review of the Literature

BACKGROUND

22q11.2 deletion syndrome confers significant risk for the development of schizophrenia. While current recommendations regarding the management of psychotic symptoms in affected individuals are generally in keeping with treatment guidelines for general schizophrenia populations, evidence for the use of clozapine has come from case reports and retrospective observational data. As no reviews on the topic currently exist, a systematic review of clozapine use in 22q11.2 deletion syndrome was completed.

METHODS

In November 2023, a literature search was completed using both PubMed and Scopus to identify English-language articles that reported the use of clozapine in humans with 22q11.2 deletion syndrome.

RESULTS

Twenty-six articles describing 57 individuals were deemed eligible for inclusion. Most individuals had a diagnosis of treatment-resistant schizophrenia. Where reported, the mean or median dose of clozapine was relatively low, and the majority of individuals exhibited a good response (approximately 65.5% across individual case reports/series). While seizures were unsurprisingly the most commonly reported serious adverse effect, the majority of individuals were able to remain on (or be restarted on) clozapine by having their dose decreased and/or by adding an anticonvulsant (most commonly valproate).

CONCLUSIONS

This review reaffirms that individuals with 22q11.2 deletion syndrome may benefit from clozapine therapy even at a low dose, assuming they meet criteria for treatment-resistant schizophrenia and provided no contraindications exist. However, given the increased incidence of seizures in 22q11.2 deletion syndrome, the use of prophylactic anticonvulsant therapy should be considered, and hypoparathyroidism/hypocalcemia screened for and corrected before the initiation of clozapine. It is also recommended that clozapine blood levels be monitored.

Transcriptional linkage analysis with in vivo AAV-Perturb-seq

The ever-growing compendium of genetic variants associated with human pathologies demands new methods to study genotype-phenotype relationships in complex tissues in a high-throughput manner1,2. Here we introduce adeno-associated virus (AAV)-mediated direct in vivo single-cell CRISPR screening, termed AAV-Perturb-seq, a tuneable and broadly applicable method for transcriptional linkage analysis as well as high-throughput and high-resolution phenotyping of genetic perturbations in vivo. We applied AAV-Perturb-seq using gene editing and transcriptional inhibition to systematically dissect the phenotypic landscape underlying 22q11.2 deletion syndrome3,4 genes in the adult mouse brain prefrontal cortex. We identified three 22q11.2-linked genes involved in known and previously undescribed pathways orchestrating neuronal functions in vivo that explain approximately 40% of the transcriptional changes observed in a 22q11.2-deletion mouse model. Our findings suggest that the 22q11.2-deletion syndrome transcriptional phenotype found in mature neurons may in part be due to the broad dysregulation of a class of genes associated with disease susceptibility that are important for dysfunctional RNA processing and synaptic function. Our study establishes a flexible and scalable direct in vivo method to facilitate causal understanding of biological and disease mechanisms with potential applications to identify genetic interventions and therapeutic targets for treating disease.

Long-term effects of early treatment with SSRIs on cognition and brain development in individuals with 22q11.2 deletion syndrome

Cognitive deficits in individuals at risk of psychosis represent a significant challenge for research, as current strategies for symptomatic treatment are often ineffective. Recent studies showed that atypical cognitive development predicts the occurrence of psychotic symptoms. Additionally, abnormal brain development is known to predate clinical manifestations of psychosis. Therefore, critical developmental stages may be the best period for early interventions expected to prevent cognitive decline and protect brain maturation. However, it is challenging to identify and treat individuals at risk of psychosis in the general population before the onset of the first psychotic symptoms. 22q11.2 deletion syndrome (22q11DS), the neurogenetic disorder with the highest genetic risk for schizophrenia, provides the opportunity to prospectively study the development of subjects at risk for psychosis. In this retrospective cohort study, we aimed to establish if early treatment with SSRIs in children and adolescents with 22q11DS was associated with long-term effects on cognition and brain development. We included 98 participants with a confirmed diagnosis of 22q11DS followed up 2-4 times (age range: 10-32). Thirty subjects without psychiatric disorders never received psychotropic medications, thirty had psychotic symptoms but were not treated with SSRIs, and 38 received SSRIs treatment. An increase in IQ scores characterized the developmental trajectories of participants receiving treatment with SSRIs, even those with psychotic symptoms. The thickness of frontal regions and hippocampal volume were also relatively increased. The magnitude of the outcomes was inversely correlated to the age at the onset of the treatment. We provide preliminary evidence that early long-term treatment with SSRIs may attenuate the cognitive decline associated with psychosis in 22q11DS and developmental brain abnormalities.

Efficacy of Low-Dose Aripiprazole for Treatment of Psychotic Symptoms in a Patient with 22q11.2 Deletion Syndrome

OBJECTIVES

The 22q11.2 deletion syndrome is one of the most prevalent genetic disorders and children suffering from this syndrome have been found to have a substantially greater risk for the development of schizophrenia and bipolar disorder. Psychiatric medications such as antipsychotics are commonly used in individuals with 22q11.2DS.

EXPERIMENTAL DESIGN

This is a case of 13 years male young man suffering from 22q11.2 deletion syndrome. Since adolescence, he presented with behavioural disorders, aggression, verbal abuse, sleep disorders.

PRINCIPAL OBSERVATIONS

The psychiatric examination confirmed the delusional idea, which was repeated in an obsessive way. There were also auditory hallucinations along with reference ideas. Aripiprazole was administered in 8 mg daily which gave more spectacular results and was better tolerated.

CONCLUSIONS

In the present situation delusional ideas are no longer mentioned, but a cognitive deduction is found. Aripiprazole can be an effective pharmacological solution for the psychotic symptoms in patients suffering from 22q11DS.

Adverse effects of antipsychotic medication in patients with 22q11.2 deletion syndrome: A systematic review

The 22q11.2 deletion syndrome (22q11.2DS) is a multisystem condition and the most prevalent microdeletion syndrome in humans. Approximately 25% of individuals with 22q11.2DS receive antipsychotic treatment. To assess whether patients with 22q11.2DS are vulnerable to adverse effects of antipsychotic medication, we carried out a literature review. A systematic search strategy was performed using PubMed (Medline), Embase, PsychInfo, and Cochrane Database of Systematic Reviews. Publications describing adverse effects of antipsychotic medication in patients with 22q11.2DS were included in the review and assessed for their methodological quality. A total of 11 publications reporting on eight trials, cross-sectional or cohort studies, and 30 case reports were included. The most commonly reported adverse effects can be classified into the following categories: movement disorders, weight gain, seizures, cardiac side effects, and cytopenias. Many of these symptoms are manifestations of 22q11.2DS, also in the absence of antipsychotic medication. Based on the reviewed literature, a causal relation between antipsychotic medication and the reported adverse effects could not be established in the majority of cases. Randomized clinical trials are needed to make firm conclusions regarding risk of adverse effects of antipsychotics in patients with 22q11.2DS.

Cinacalcet Treatment in an Adolescent With Concurrent 22q11.2 Deletion Syndrome and Familial Hypocalciuric Hypercalcemia Type 3 Caused by AP2S1 Mutation

CONTEXT

The 22q11.2 deletion syndrome (DS) is a common multiple anomaly syndrome in which typical features include congenital heart defects, facial dysmorphism, and palatal anomalies. Hypocalcemia due to hypoparathyroidism is a common endocrine manifestation resulting from variable parathyroid hypoplasia, but hypercalcemia has not previously been reported in 22q11.2 DS.

CASE DESCRIPTION

Our patient is a 16-year-old adolescent male with dysmorphic facial features and delayed motor and speech development. At 2 years of age, 22q11.2 DS was confirmed by fluorescence in situ hybridization. In contrast to hypoparathyroidism that is usually seen in 22q11.2 DS, this patient had early childhood-onset hypercalcemia with inappropriately high PTH levels and hypocalciuria. Genomic DNA was obtained from the proband and screened for calcium-sensing receptor (CASR) mutations with negative results. No parathyroid tissue could be localized by imaging or surgical exploration. As a result of symptomatic hypercalcemia, the patient was treated with a calcimimetic (cinacalcet). During the treatment, plasma calcium normalized with mild symptoms of hypocalcemia. After discontinuation of cinacalcet, calcium returned to high pretreatment levels. Further DNA analysis of adaptor protein-2 σ subunit (AP2S1) showed a heterozygous missense mutation c.44 G>T, resulting in a p.R15L substitution; the mutation was absent in the healthy parents and two siblings.

CONCLUSIONS

Hypercalcemia in our patient with 22q11.2 DS could be explained by the de novo mutation in AP2S1. Identification of a genetic cause for hypercalcemia is helpful in guiding management and avoiding unnecessary treatment.

ASD, ADHD, mental health conditions and psychopharmacology in neurogenetic syndromes: parent survey

BACKGROUND

There are a number of neurogenetic syndromes with well described behavioural phenotypes including fragile X syndrome, Prader-Willi syndrome, Williams syndrome and velo-cardio-facial syndrome (VCFS). Autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD) and psychiatric conditions are often associated with the syndromes.

METHOD

Parents (n = 381) of school-aged children with one of the four syndromes in the UK and Ireland were asked whether their child had been professionally diagnosed with ASD, ADHD or a mental health condition. Parents were also asked whether their child had been prescribed medication for behavioural or psychiatric reasons.

RESULTS

The highest level of reported diagnoses of ASD and ADHD was in fragile X syndrome. In all syndrome groups, lower rates of diagnosis were reported in comparison to previously published research. Prescribing of medication for behavioural/psychiatric reasons was highest in fragile X syndrome although the highest usage of melatonin was in Williams syndrome.

CONCLUSION

Reasons for a lower recognition of ASD, ADHD and mental health conditions in clinical practice compared with research studies may include 'diagnostic overshadowing' due to presence of intellectual disability and a genetic syndrome. However, there may also be a lack of belief in the utility of such diagnoses in neurogenetic syndromes among relevant professionals and/or lack of access to professionals with sufficient expertise in the recognition of such diagnoses in those with neurogenetic syndromes. The low rates of prescribing of medication for behavioural/psychiatric reasons may reflect the low level of clinical diagnoses or lack of belief in the utility of psychopharmacology in this population.

Cognitive-adaptive disabilities

Cognitive-adaptive disabilities (CADs) are not frequently seen in the general pediatric setting. Yet, given the high rates of comorbidity in that population, they commonly demand a lot of time and effort on the part of clinicians. One aspect of comorbidity is the degree to which psychiatric disorders occur in children, adolescents, and young adults with CADs. This article reviews the epidemiology, associated psychopathology, and pharmacologic treatment of selected CADs.

[Calcitriol administration during pregnancy in a partial DiGeorge anomaly]

A 23-year-old pregnant woman was known since birth to have partial DiGeorge syndrome with idiopathic hypoparathyroidism and clinically suspected thymus hypoplasia. The hypocalcaemia had until recently been treated with 1000 IU vitamin D3 daily. During the 9th week of pregnancy the serum calcium level was 1.9 mmol/l, the phosphate one 1.58 mmol/l and parathormone 5.6 pg/ml. To ensure better control, calcitriol was given (1.25-[OH]2-vitamin D3, initially 1 microgram daily and then, from the 22nd week of pregnancy onward, 1.5 micrograms daily), as well as calcium gluconate and lactate (initially 300 mg daily, then 900 mg daily). The serum calcium level at that time was between 2.0 and 2.5 mmol/l. Because of toxaemia of pregnancy the patient was hospitalized and confined to bed during the 37th week, whereupon the serum calcium level rose from 2.2 to 2.7 mmol/l, but a decrease in calcitriol dosage resulted in a decrease to within normal limits within one day. A girl was delivered by section in the 39th week: she had normal serum calcium and phosphate levels and appeared healthy.

Hypoparathyroidism in Arab children

Four children with hypoparathyroidism are reported. We believe that this is the first report of this condition from Kuwait or Saudi Arabia. Treatment and course of disease are discussed. Two children have hypoparathyroidism as part of DiGeorge Syndrome.

Results in two infants with the DiGeorge syndrome--effects of long-term TP5

We treated two patients affected by DiGeorge syndrome with long-term administration of the synthetic thymic hormone thymopoietin (TP5). In both cases we obtained durable immunological reconstitution, starting as early as 2 weeks after beginning of TP5 treatment. High levels of circulating immature thymocytes and precursor T cells (defined by monoclonal antibodies OKT6, OKT9, and OKT10) were present prior to therapy, and they steadily decreased during the first few weeks of study. During the same time, phenotypically mature T lymphocytes (OKT3+ and OKT4+/OKT8+) markedly increased, thereafter remaining at near normal levels. OKT10+ cells appeared to rise again after 3 months of TP5 treatment. In vitro function of T cells, assessed by PHA stimulation, and in vivo cell-mediated immunity (skin tests with Candida) were normal at 3 and at 2 months, respectively, after initiation of therapy. No severe infection episodes were recorded and normal development was achieved. No side effect or adverse reaction occurred. In these two patients the other features of the DiGeorge syndrome were successfully treated by early cardiac surgery and vitamin D therapy. The immunological reconstitution, in absence of functioning thymus observed in these two cases, provides further evidence of the effectiveness of long-term treatment with thymic hormones--with maintenance of the improvement of cell-mediated immunity.

Complex transposition with interrupted right aortic arch and partial Di George syndrome: successful palliation with combined medical and surgical therapy

A five-day-old infant with transposition of the great arteries, ventricular septal defect, and an interrupted right aortic arch underwent successful balloon septostomy, pulmonary artery banding, and aortic arch repair. The infant also had abnormal facies with severe refractory hypocalcemia and depressed T-lymphocyte number and function believed to represent a partial Di George syndrome. The hypocalcemia resolved following treatment with a vitamin-D analogue, T-cell number increased, and T-cell function improved, but both remained subnormal.

DiGeorge's syndrome in monozygotic twins. Treatment with calcitriol

Monozygotic male twins with DiGeorge's syndrome had facial dysmorphism, cardiovascular abnormalities, hypocalcemia, and immunodeficiency; however, they showed differences in several aspects of this developmental complex. An early gestational insult, rather than a mutation, may be one cause of this heterogenous disorder. One twin had clinically appreciable hypoparathyroidism and had received calcitriol since early infancy. Despite close monitoring of therapy, he experienced two episodes of unexpected and prolonged hypercalcemia. Following the first episode, he was eucalcemic for nine weeks without therapy, attesting to the prolonged biological effects of calcitriol when used in the treatment of hypoparathyroidism.

Thymopoietin pentapeptide treatment of primary immunodeficiencies

26 patients with primary immunodeficiencies (3 infants with severe combined immunodeficiency [SCID] 3 with DiGeorge syndrome, 6 with T-cell defect or SCID with B cells, 4 with common variable hypogammaglobulinaemia and associated T-cell defect, 5 with ataxia-telangiectasia, and 5 with hyper-IgE syndrome) were treated with thymopoietin pentapeptide (TP-5) at a dose of 0 . 5 mg/kg daily for 2 weeks and then 3 times a week at 0 . 5 mg/kg for 10 weeks, 3 patients with DiGeorge syndrome and 3 with primary T-cell defect demonstrated pronounced clinical and immunological improvement during treatment. None of the patients with SCID and 3 of 6 patients with SCID with B cells or primary T-cell defect showed any clinical or immunological changes during therapy. In 5 patients with ataxia-telangiectasia clinical manifestations and immunological tests were unchanged by TP-5. Abnormality of T cells in cases of hyper-IgE syndrome was not corrected by TP-5 treatment.

A case of Di George syndrome treated with thymopoietin pentapeptide (TP-5) demonstrating an adherent suppressor cell of lymphocyte function

A child with the classical features of Di George syndrome is described. The patient was treated with TP-5 and the number of peripheral blood E-rosette forming cells rose from 11% to 69% but then fell to 33% prior to death. There was poor correlation between the number of T-cells estimated by rosetting with sheep red blood cells and that measured by cytotoxicity to the OKT3 antiserum and complement. Although the total T-cell numbers were reduced, the ratio of inducer/helper cells: suppressor/cytotoxic cells remained normal as assessed by the use of the specific monoclonal antisera OKT4 and OKT8. Lymphocyte proliferation after mitogenic activation and the production of lymphocyte mitogenic factor by PWM stimulated lymphocytes was significantly depressed but was considerably improved by the removal of adherent cells. It appears as though an adherent suppressor cell was partially responsible for the depressed lymphocyte function observed in this patient.

Induction of E-rosette-promoting factor in human plasma by levamisole: an assessment in a patient with partial DiGeorge syndrome

A male infant with partial DiGeorge syndrome responded to weekly administration of levamisole (2.5 mg/kg of body weight) with an increase of circulating E-rosette-forming T cells. Thymic hormone activity in plasma appeared to be elevated to a near-normal level of 11.6 ng thymopoietin equivalent/ml after levamisole administration. The in vitro incubation studies indicated that levamisole by itself had no E-rosette-promoting ability, but a dialysable and relatively heat-stable plasma factor induced by levamisole both in the patient and in healthy individuals had E-rosette-promoting activity for the patient's lymphocytes. Such a plasma factor, however, could not be induced in all four thymectomized myasthenic subjects examined, suggesting a thymus-dependent nature of the plasma factor. These results suggest that levamisole might mediate an increased secretion of humoral factor(s) with E-rosette-promoting activity, even from such a rudimentary thymus as in the partial DiGeorge syndrome.

Thymosin therapy in the DiGeorge syndrome

Reconstruction of the T-cell immune defect in patients with the DiGeorge syndrome has been accomplished in the past by fetal thymus transplantation. Because of the risk of fatal graft-versus-host reaction with fetal thymus transplantation in patients with abnormal T-cell immunity, we have examined the effects of a thymus tissue extract, thymosin fraction 5, on the in vitro and in vivo immune function in children with the DiGeorge syndrome. T-cell numbers were increased with thymosin F5 in vitro in three of five patients. T-cell number and function was improved in three of four patients treated with thymosin F5 in vivo. Spontaneous improvement in the immune function of these patients cannot be excluded. These results suggest, however, that further trials with thymosin F5 therapy may be indicated in patients with the DiGeorge syndrome.