Benefits for children with suspected cancer from routine whole-genome sequencing.

Clinical whole-genome sequencing (WGS) has been shown to deliver potential benefits to children with cancer and to alter treatment in high-risk patient groups. It remains unknown whether offering WGS to every child with suspected cancer can change patient management. We collected WGS variant calls and clinical and diagnostic information from 281 children (282 tumors) across two English units (n = 152 from a hematology center, n = 130 from a solid tumor center) where WGS had become a routine test. Our key finding was that variants uniquely attributable to WGS changed the management in ~7% (20 out of 282) of cases while providing additional disease-relevant findings, beyond standard-of-care molecular tests, in 108 instances for 83 (29%) cases. Furthermore, WGS faithfully reproduced every standard-of-care molecular test (n = 738) and revealed several previously unknown genomic features of childhood tumors. We show that WGS can be delivered as part of routine clinical care to children with suspected cancer and can change clinical management by delivering unexpected genomic insights. Our experience portrays WGS as a clinically impactful assay for routine practice, providing opportunities for assay consolidation and for delivery of molecularly informed patient care.

Mutations in Myosin 5B in Children With Early-onset Cholestasis.

OBJECTIVES: Mutations in Myosin 5B (MYO5B) are known to be associated with microvillous inclusion disease (MVID) a genetic cause of neonatal intractable diarrhoea. More recently, they have been reported in children with cholestasis but without typical gastrointestinal symptoms of MVID. We describe our series of children with cholestasis and mutations in MYO5B. METHODS: Clinical, laboratory, and histological data were collected from patients with cholestasis and pathogenic mutations in MYO5B, found by next generation sequencing (NGS) but with minimal gastrointestinal disease. RESULTS: Six patients (3 boys) were identified. Median age at presentation was 19 months (range, 3-92). Presenting features were jaundice, pale stools, pruritus, and failure to thrive. Patients 5 and 6 had intractable diarrhoea until the age of 3 and 7 years, respectively, but currently are on full enteral diet with no intestinal symptoms. Median values for serum total bilirubin were 55 µmol/L (2-500), alanine aminotransferase 73I IU/L (32-114), γ-glutamyltransferase 7 IU/L (7-10), and serum bile acids 134 µmol/L (18-274). Three patients underwent 1 or more types of biliary diversion for symptom control. Median follow-up was 5 years (2-22). At most recent follow-up, they all reported pruritus while on antipruritics. Patient 1 had a liver transplant. CONCLUSIONS: We identified 6 patients, with mutations in MYO5B, early-onset cholestasis and pruritus, with variable response to biliary diversion without typical MVID.