22q11.2 duplication: a review of neuropsychiatric correlates and a newly observed case of prototypic sociopathy

Preliminary study of noninvasive prenatal screening for 22q11.2 deletion/duplication syndrome using multiplex dPCR assay

OBJECTIVE

This study aimed to establish a cell-free fetal DNA (cffDNA) assay using multiplex digital PCR (dPCR) for identifying fetuses at increased risk of 22q11.2 deletion/duplication syndrome.

METHODS

Six detection sites and their corresponding probes were designed for the 22q11.2 recurrent region. A dPCR assay for the noninvasive screening of 22q11.2 deletion/duplication syndrome was established. A total of 130 plasma samples from pregnant women (including 15 samples with fetal 22q11.2 deletion/duplication syndrome) were blindly tested for evaluating the sensitivity and specificity of the established assay.

RESULTS

DNA with different sizes of 22q11.2 deletion/duplication was detected via dPCR, indicating that the designed probes and detection sites were reasonable and effective. In the retrospective clinical samples, 11 out of 15 samples of pregnant women with 22q11.2 deletion/duplication were detected during the cffDNA assay, and accurate regional localization was achieved. Among the 115 normal samples, 111 were confirmed to be normal. Receiver operating characteristic curves were used for assessing the cut-off values and AUC for these samples. The sensitivity, specificity, and positive as well as negative predictive values were 73.3%, 96.5%, 73.3%, and 96.5%, respectively.

CONCLUSION

The cffDNA assay based on dPCR technology for the noninvasive detection of 22q11.2 recurrent copy number variants in fetuses detected most affected cases, including smaller but relatively common nested deletions, with a low false-positive rate. It is a potential, efficient and simple method for the noninvasive screening of 22q11.2 deletion/duplication syndrome.

22q11.2 recurrent copy number variation-related syndrome: a retrospective analysis of our own microarray cohort and a systematic clinical overview of ClinGen curation

BACKGROUND

Chromosomal 22q11.2 dosage changes in the recurrent region can lead to a series of clinically variable pediatric syndromes. This study conducted a retrospective analysis of microarray tested cases with 22q11.2 recurrent copy number variations (CNVs) at our laboratory from September 2018 to August 2021, and provides a systematical clinical overview of ClinGen curation.

METHODS

The data of 34 microarray tested cases with 22q11.2 recurrent CNVs at our laboratory from September 2018 to August 2021 were retrospectively analyzed, and the variant types, abnormal chromosome regions, clinical phenotypes, and follow-up information were evaluated and summarized. A ClinGen Dosage Sensitivity Map was retrieved for "22q11.2". The information of each 22q11.2 recurrent region was collected and systematically classified.

RESULTS

We reported 34 cases (including 18 22q11.2 microdeletion cases and 16 microduplication cases) from 8,465 microarrays. Of the 22q11.2 recurrent CNV-carried samples, 74% (25/34) comprised prenatal amniotic fluid or villus, and up to 50% (17/34) of the cases contained the proximal A-D interval. Across these 22q11.2 microdeletion samples, the congenital cardiovascular defect, which mainly included the tetralogy of fallot, ventricular septal defect, and patent foramen ovale, was identified as the most common feature (13/18, 72%). However, 22q11.2 microduplication cases exhibited a broad range of highly variable phenotypes, spanning from severe abnormality to mild characteristics and even the completely normal phenotype. This study also systematically reviewed the ClinGen dosage sensitivity curation on 22q11.2 recurrent regions, and found that A-D/A-B haploinsufficiency score reached "3", responsible for DiGeorge syndrome (DGS)/velocardiofacial syndrome (VCFS). Also, A-D/A-B triplosensitivity score "3" could further account for multiple variable phenotypes.

CONCLUSIONS

Taken together, this study provides clinical overview of the ClinGen curation and data support for the American College of Medical Genetics and Genomics (ACMG) evaluation in the pathogenicity of each interval involved in 22q11.2 recurrent deletion and duplication. Certainly, more evidences on the genotype-phenotype contributions of different 22q11.2 recurrent CNVs need to be gathered.

Toward Actionable Practice Parameters for "Dual Diagnosis": Principles of Assessment and Management for Co-Occurring Psychiatric and Intellectual/Developmental Disability

PURPOSE OF REVIEW

Although treatment algorithms and parameters for best practice are readily available for all major syndromes of psychiatric impairment, the occurrence of psychiatric syndromes in individuals with intellectual and developmental disability (IDD) invokes serious contextual challenges for interpretation of symptoms, diagnosis, and optimization of treatment, both for clinicians and for the service sectors in which care and support of individuals with IDD are delivered. Recognizing that there exist very few definitive resources for best practice under the circumstance of this form of "dual diagnosis," the Missouri Department of Mental Health convened an expert panel to conduct a focused review and synthesis of the relevant scientific literature from which to develop guidance in the form of decision support to clinicians. This article summarizes the findings for three of the most common and impairing clusters of psychiatric symptoms that co-occur with IDD-aggression, depression, and addictions.

RECENT FINDINGS

Individuals with IDD are at high risk for the development of psychiatric symptoms (PS), which often manifest uniquely in IDD and for which evidence for effective intervention is steadily accruing. Interventions that are commonly implemented in the IDD service sector (e.g., functional communication training and positive behavioral support planning) are capable of mitigating severe behavioral impairment, yet rarely invoked when dual diagnosis patients are seen in the psychiatric service sector. Conversely, state-of-the-art interventions for traumatic stress, pharmacotherapy, and psychotherapy have proven capable of improving behavioral impairments in IDD but are typically restricted to the psychiatric service sector, where there exist significant barriers to access for patients with IDD, including limitations imposed by diagnostic eligibility and practitioner experience. Bridging these gaps in knowledge and clinical capacity across the respective IDD and PS service sectors should be of very high priority in strategizing the care and support of IDD patients with serious co-occurring psychiatric conditions.