High-depth next-generation sequencing panel testing in the evaluation of arteriovenous malformations.

Arteriovenous malformations (AVMs) are vascular lesions in which an overgrowth of blood vessels of varying sizes develops with one or more direct connections between the arterial and venous circulation. We performed a retrospective review of a cohort of 54 patients with AVMs referred to our clinical genomic laboratory for high-depth next-generation sequencing (NGS) panel of Disorders of Somatic Mosaicism (DoSM). Thirty-seven of 54 patients were female (68.5%). Among the 54 cases, 37 (68.5%) cases had pathogenic and/or likely pathogenic (P/LP) variants identified, two cases (3.7%) had variants of uncertain clinical significance, and the remaining 15 cases (27.8%) had negative results. MAP2K1 variants were found in 12 cases, followed by eight cases with KRAS variants and seven with TEK variants, and the remainder being identified in several other genes on the panel. Among the 37 positive cases, 32 cases had somatic alterations only; the remaining five cases had at least one germline P/LP variant, including four cases with PTEN and one with RASA1. Of note, two cases had the unexpected co-existence of two P/LP variants. In summary, this study illustrated the molecular diagnostic yield (68.5%) of this cohort of patients with a clinical indication of AVMs by our high-depth DoSM NGS panel.

Clinical and molecular characteristics of a novel rare de novo variant in PPP2CA in a patient with a developmental disorder, autism, and epilepsy.

PP2A-related (neuro) developmental disorders are a family of genetic diseases caused by a heterozygous alteration in one of several genes encoding a subunit of type 2A protein phosphatases. Reported affected genes, so far, are PPP2R5D, encoding the PP2A regulatory B56δ subunit; PPP2R1A, encoding the scaffolding Aα subunit; and PPP2CA, encoding the catalytic Cα subunit-in that order of frequency. Patients with a pathogenic de novo mutation in one of these genes, in part, present with overlapping features, such as generalized hypotonia, intellectual and developmental delay, facial dysmorphologies, seizures, and autistic features, and, in part, with opposite features, e.g., smaller versus larger head sizes or normal versus absent corpus callosum. Molecular variant characterization has been consistent so far with loss-of-function or dominant-negative disease mechanisms for all three affected genes. Here, we present a case report of another PPP2CA-affected individual with a novel de novo missense variant, resulting in a one-amino acid substitution in the Cα subunit: p.Cys196Arg. Biochemical characterization of the variant revealed its pathogenicity, as it appeared severely catalytically impaired, showed mildly affected A subunit binding, and moderately decreased binding to B/B55, B"/PR72, and all B56 subunits, except B56γ1. Carboxy-terminal methylation appeared unaffected, as was binding to B"'/STRN3-all being consistent with a partial loss of function. Clinically, the girl presented with mild-to-moderate developmental delay, a full-scale IQ of 83, mild dysmorphic facial features, tonic-clonic seizures, and autistic behaviors. Brain MRI appeared normal. We conclude that this individual falls within the milder end of the clinical and molecular spectrum of previously reported PPP2CA cases.

Factors affecting pathways to care for children and adolescents with complex vascular malformations: parental perspectives.

BACKGROUND: Complex vascular malformations (VMs) are rare disorders that can cause pain, coagulopathy, disfigurement, asymmetric growth, and disability. Patients with complex VMs experience misdiagnosis, delayed diagnosis, delayed or inappropriate treatments, and worsened health. Given the potential consequences of delaying expert care, we must identify the factors that impede or facilitate this access to care. RESULTS: We performed semi-structured interviews with 24 parents (21 mothers; 3 fathers; median age = 42.5 years) of children with complex VMs and overgrowth disorders living in the US, recruited through two patient advocacy groups - CLOVES Syndrome Community, and Klippel-Trenaunay Support Group. We performed thematic analysis to assess parental perspectives on barriers and facilitators to accessing expert care. We identified 11 factors, representing 6 overarching themes, affecting families' ability to access and maintain effective care for their child: individual characteristics (clinician behaviors and characteristics, parent behaviors and characteristics), health care system (availability of specialist multidisciplinary teams, care coordination and logistics, insurance and financial issues, treatments and services), clinical characteristics (accuracy and timing of diagnosis, features of clinical presentation), social support networks, scientific progress, and luck and privilege. Additionally, access to information about VMs and VM care was a crosscutting theme affecting each of these factors. These factors influenced both the initial access to care and the ongoing maintenance of care for children with VMs. CONCLUSION: Parents of children with VMs report multiple factors that facilitate or impede their ability to provide their child with optimal care. These factors represent possible targets for future interventions to improve care delivery for families affected by VMs.

Road map to developing a fellowship program in a tertiary care hospital.

BACKGROUND: The American Academy of Pediatrics has identified the need for more subspecialists. Beginning a pediatric pulmonary fellowship program in a tertiary care hospital can be a challenging process. Persistence, perseverance, and working through barriers to education are important strides to take toward achieving this goal. We share our experience with this endeavor. The objective of this study was to describe our experience developing a pediatric pulmonary fellowship program, the challenges we faced, and the methods we used to meet and overcome those challenges. METHODS: Self-reflection by the program director, associate director, and coordinator involved in the development and implementation of a successful fellowship program. This includes the step by step process, effort, and time commitment needed for planning and implementing a fellowship program. Our goals are to share this information with the medical community. RESULTS/OUTCOMES/IMPROVEMENTS: Planning, preparing, and implementing a pediatric pulmonary fellowship program can be challenging in the current economic climate, especially considering budget constraints and increasingly demanding clinical mandates. Department chairs and administrators view work relative value units as a marker for remuneration; educational efforts are more often an unfunded mandate. Major difficulties included imposing new educational expectations on the clinical staff and expanding the budget to include fellows' costs. Developing a program information form (PIF) was a work-in-progress over a two-year period with the dedicated staff meeting regularly during this time.

A 15-year old girl with asthma and lower lobe bronchiectasis.

Wet cough, wheeze, and sputum in an adolescent with evidence for bronchiectasis is an uncommon presentation. The differential diagnosis includes cystic fibrosis (CF), immunodeficiency disorders, complement deficiency, allergic bronchopulmonary aspergillosis, alpha-1 antitrypsin disease, repeated aspiration pneumonia, foreign body, bronchial carcinoid, unresolved right middle lobe pneumonia, and primary ciliary dyskinesia (PCD). The likely diagnosis proceeds from the more to less common in patients with these symptoms. The location of disease on computed tomography scanning, nasal and bronchial exhaled nitric oxide, identification of ultrastructural defects on electron microscopy, and specific genetic mutation help separate CF and PCD. Although differentiating these conditions is vital, the chronic management of the bronchiectasis usually includes clearance mechanisms, bronchodilators, regular exercise, appropriate vaccinations, and judicious antibiotics for airway infections.

Genetic diversity of arginine catabolic mobile element in Staphylococcus epidermidis.

BACKGROUND: The methicillin-resistant Staphylococcus aureus clone USA300 contains a novel mobile genetic element, arginine catabolic mobile element (ACME), that contributes to its enhanced capacity to grow and survive within the host. Although ACME appears to have been transferred into USA300 from S. epidermidis, the genetic diversity of ACME in the latter species remains poorly characterized. METHODOLOGY/PRINCIPAL FINDINGS: To assess the prevalence and genetic diversity of ACME, 127 geographically diverse S. epidermidis isolates representing 86 different multilocus sequence types (STs) were characterized. ACME was found in 51% (65/127) of S. epidermidis isolates. The vast majority (57/65) of ACME-containing isolates belonged to the predominant S. epidermidis clonal complex CC2. ACME was often found in association with different allotypes of staphylococcal chromosome cassette mec (SCCmec) which also encodes the recombinase function that facilities mobilization ACME from the S. epidermidis chromosome. Restriction fragment length polymorphism, PCR scanning and DNA sequencing allowed for identification of 39 distinct ACME genetic variants that differ from one another in gene content, thereby revealing a hitherto uncharacterized genetic diversity within ACME. All but one ACME variants were represented by a single S. epidermidis isolate; the singular variant, termed ACME-I.02, was found in 27 isolates, all of which belonged to the CC2 lineage. An evolutionary model constructed based on the eBURST algorithm revealed that ACME-I.02 was acquired at least on 15 different occasions by strains belonging to the CC2 lineage. CONCLUSIONS/SIGNIFICANCE: ACME-I.02 in diverse S. epidermidis isolates were nearly identical in sequence to the prototypical ACME found in USA300 MRSA clone, providing further evidence for the interspecies transfer of ACME from S. epidermidis into USA300.

Parapneumonic effusion and empyema in children: retrospective review of the duPont experience.

Management of pediatric parapneumonic effusions and empyema remains controversial. Treatment includes antibiotics, chest tube, fibrinolytic therapy, video-assisted thoracoscopy and debridement, and open thoracotomy and decortication. A retrospective 10-year study was done to identify patient selection variables for specific therapies. Charts (n = 101) with diagnoses of empyema without comorbidity were reviewed, a database was developed, and variables between patients who did and did not receive thoracoscopic debridement were compared at admission and during hospitalization. The difference in positive culture reports with video-assisted thoracoscopy compared with medical management was significant (P < .018). Postsurgical patients used the intensive care unit and had 2 or more chest tubes with greater frequency than medically managed patients (P < .014, P < .002). Antibiotics, video-assisted thoracoscopy, and chest tube within 48 hours of admission shortened hospitalization by 4 days (P < .001) compared with delayed video-assisted thoracoscopy done after 48 hours of admission.

A pseudo-outbreak of Chlamydia trachomatis in a state residential facility: implications for diagnostic testing.

In December 1998, an outbreak of Chlamydia trachomatis genital infections was reported among 18 residents of a state residential facility housing 392 mentally retarded clients. The initial patient tested positive by ligase chain reaction (LCR); 17 others tested positive by culture. Serologic test results for C. trachomatis antibodies in patients who had tested positive by culture were negative. Further testing showed that C. trachomatis DNA could not be detected in the LCR specimen or in any reportedly positive culture specimens. At the original culture laboratory, C. trachomatis culture was infrequently performed, and positive controls were not adequately prepared. This pseudo-outbreak highlights problems that may occur with C. trachomatis testing. As experience with C. trachomatis culture declines, laboratories performing this test should ensure quality and consider confirmatory testing. For C. trachomatis screening tests, the need for confirmatory testing depends on individual patient considerations (including medical-legal implications) and prevalence of infection in the tested population.