Rapid Whole Genome Sequencing Diagnoses and Guides Treatment in Critically Ill Children in Belgium in Less than 40 Hours.

Rapid Whole Genome Sequencing (rWGS) represents a valuable exploration in critically ill pediatric patients. Early diagnosis allows care to be adjusted. We evaluated the feasibility, turnaround time (TAT), yield, and utility of rWGS in Belgium. Twenty-one unrelated critically ill patients were recruited from the neonatal intensive care units, the pediatric intensive care unit, and the neuropediatric unit, and offered rWGS as a first tier test. Libraries were prepared in the laboratory of human genetics of the University of Liège using Illumina DNA PCR-free protocol. Sequencing was performed on a NovaSeq 6000 in trio for 19 and in duo for two probands. The TAT was calculated from the sample reception to the validation of results. Clinical utility data were provided by treating physicians. A definite diagnosis was reached in twelve (57.5%) patients in 39.80 h on average (range: 37.05-43.7). An unsuspected diagnosis was identified in seven patients. rWGS guided care adjustments in diagnosed patients, including a gene therapy, an off-label drug trial and two condition-specific treatments. We successfully implemented the fastest rWGS platform in Europe and obtained one of the highest rWGS yields. This study establishes the path for a nationwide semi-centered rWGS network in Belgium.

Phenotype-Genotype Correlation in Children with Neurofibromatosis Type 1.

Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder with an incidence of ∼1 in 4,000 live births. Neurofibromin, the gene product, is ubiquitously expressed at high levels in the nervous system and functions as a tumor suppressor. Haploinsufficiency of neurofibromin through mutation leads to an increased risk of developing benign and malignant tumors in affected individuals. Although NF1 has complete penetrance, it displays considerable inter- and intrafamilial variability in phenotypic expression which poses disease prediction and management problems. Some NF1 genotype-phenotype correlations have been described. To evaluate the genetic component of variable expressivity in NF1, we examined the phenotypic correlations between affected relatives in 52 NF1 patients from 45 families.

Horner Syndrome in Children: A Clinical Condition with Serious Underlying Disease.

Aim Horner syndrome corresponds to the clinical triad of miosis, ptosis, and facial anhidrosis. These symptoms are related to injury of the oculosympathetic chain. In children, Horner syndrome is classified as congenital or acquired. While the diagnosis is made through clinical examination, there is some debate regarding the use of imaging modalities and the extent of anatomical coverage required. Methods Here, we describe two cases of children with acute Horner syndrome. We then review the literature about the different etiology and discuss the interest of some investigations. Results Case 1: An 8-month-old girl without personal or familial history, has presented a right acquired Horner syndrome without additional signs. Frontal chest radiography and ultrasonography of the neck and the abdomen was first achieved and returned normal. The cerebral and cervical magnetic resonance imaging (MRI) with angiographic sequences performed in a second time was also normal. Finally, an enhanced thoracic computed tomography (CT)-scan demonstrated a mass at the right pulmonary apex. Case 2: A 9-year-old boy without personal or familial history has presented an acute headache with loss of consciousness during a basketball competition. Upon waking up, the child has right hemiplegia, aphasia, and left Horner syndrome. The cerebral CT scan realized in the first line was normal. The MRI with angiographic sequences demonstrated M1 left carotid dissection with homolateral white matter infarction. Conclusion Imaging studies seem critical in delineating the nature and extent of any underlying pathology along the oculosympathetic pathway in children presenting a Horner syndrome. In these patients, a history of trauma or surgery may reduce the need for extensive systemic evaluation. Without such anamnesis, a decision to proceed with further evaluation is made with consideration of the relative incidence of tumor, especially neuroblastoma, or other treatable lesions. In this condition, MRI is the more sensitive and recommended investigation.