👤 Anna Poluha

Several studies have indicated that broad genomic characterization of childhood cancer provides diagnostically and/or therapeutically relevant information in selected high-risk cases. However, the extent to which such characterization offers clinically actionable data in a prospective broadly inclusive setting remains largely unexplored. We implemented prospective whole-genome sequencing (WGS) of tumor and germline, complemented by whole-transcriptome sequencing (RNA-Seq) for all children diagnosed with a primary or relapsed solid malignancy in Sweden. Multidisciplinary molecular tumor boards were set up to integrate genomic data in the clinical decision process along with a medicolegal framework enabling secondary use of sequencing data for research purposes. During the study's first 14 months, 118 solid tumors from 117 patients were subjected to WGS, with complementary RNA-Seq for fusion gene detection in 52 tumors. There was no significant geographic bias in patient enrollment, and the included tumor types reflected the annual national incidence of pediatric solid tumor types. Of the 112 tumors with somatic mutations, 106 (95%) exhibited alterations with a clear clinical correlation. In 46 of 118 tumors (39%), sequencing only corroborated histopathological diagnoses, while in 59 cases (50%), it contributed to additional subclassification or detection of prognostic markers. Potential treatment targets were found in 31 patients (26%), most commonly Up-front, large-scale genomic characterization of pediatric solid malignancies provides diagnostically valuable data in the majority of patients also in a largely unselected cohort. Show less

Tricho-rhino-phalangeal syndrome (TRPS) is characterized by craniofacial and skeletal abnormalities, and subdivided in TRPS I, caused by mutations in TRPS1, and TRPS II, caused by a contiguous gene deletion affecting (amongst others) TRPS1 and EXT1. We performed a collaborative international study to delineate phenotype, natural history, variability, and genotype-phenotype correlations in more detail. We gathered information on 103 cytogenetically or molecularly confirmed affected individuals. TRPS I was present in 85 individuals (22 missense mutations, 62 other mutations), TRPS II in 14, and in 5 it remained uncertain whether TRPS1 was partially or completely deleted. Main features defining the facial phenotype include fine and sparse hair, thick and broad eyebrows, especially the medial portion, a broad nasal ridge and tip, underdeveloped nasal alae, and a broad columella. The facial manifestations in patients with TRPS I and TRPS II do not show a significant difference. In the limbs the main findings are short hands and feet, hypermobility, and a tendency for isolated metacarpals and metatarsals to be shortened. Nails of fingers and toes are typically thin and dystrophic. The radiological hallmark are the cone-shaped epiphyses and in TRPS II multiple exostoses. Osteopenia is common in both, as is reduced linear growth, both prenatally and postnatally. Variability for all findings, also within a single family, can be marked. Morbidity mostly concerns joint problems, manifesting in increased or decreased mobility, pain and in a minority an increased fracture rate. The hips can be markedly affected at a (very) young age. Intellectual disability is uncommon in TRPS I and, if present, usually mild. In TRPS II intellectual disability is present in most but not all, and again typically mild to moderate in severity. Missense mutations are located exclusively in exon 6 and 7 of TRPS1. Other mutations are located anywhere in exons 4-7. Whole gene deletions are common but have variable breakpoints. Most of the phenotype in patients with TRPS II is explained by the deletion of TRPS1 and EXT1, but haploinsufficiency of RAD21 is also likely to contribute. Genotype-phenotype studies showed that mutations located in exon 6 may have somewhat more pronounced facial characteristics and more marked shortening of hands and feet compared to mutations located elsewhere in TRPS1, but numbers are too small to allow firm conclusions. Show less