Ronja S. Adam

Previously, colorectal cancer (CRC) has been classified into four distinct molecular subtypes based on transcriptome data. These consensus molecular subtypes (CMSs) have implications for our understanding of tumor heterogeneity and the prognosis of patients. So far, this classification has been based on the use of messenger RNAs (mRNAs), although microRNAs (miRNAs) have also been shown to play a role in tumor heterogeneity and biological differences between CMSs. In contrast to mRNAs, miRNAs have a smaller size and increased stability, facilitating their detection. Therefore, we built a miRNA‐based CMS classifier by converting the existing mRNA‐based CMS classification using machine learning (training dataset of n = 271). The performance of this miRNA‐assigned CMS classifier (CMS‐miRaCl) was evaluated in several datasets, achieving an overall accuracy of ~ 0.72 (0.6329–0.7987) in the largest dataset (n = 158). To gain insight into the biological relevance of CMS‐miRaCl, we evaluated the most important features in the classifier. We found that miRNAs previously reported to be relevant in microsatellite‐instable CRCs or Wnt signaling were important features for CMS‐miRaCl. Following further studies to validate its robustness, this miRNA‐based alternative might simplify the implementation of CMS classification in clinical workflows.

Reported cases of “pure” duplication of the entire short arm of chromosome 16 (16p) are rare, with only 7 patients described in the literature. We report on a female infant with de novo 16p duplication localized to the short arm of chromosome 6, detected by chromosomal analysis and characterized by array CGH and fluorescence in situ hybridization. This baby girl presented with clinical symptoms characteristic of patients with duplications of the short arm of chromosome 16: psychomotor retardation, constitutional growth delay and specific dysmorphic features, including proximally placed hypoplastic thumbs. In addition, she exhibited evidence of neonatal hemochromatosis as shown by direct hyperbilirubinemia, iron overload and elevated liver enzyme levels. To our knowledge, this is the first report of signs of neonatal hemochromatosis in a patient with 16p duplication.