Dihydropyrimidine dehydrogenase (DPD) is the initial enzyme acting in the catabolism of the widely used antineoplastic agent 5-fluorouracil (5FU). DPD deficiency is known to cause a potentially lethal toxicity following administration of 5FU. Here, we report novel genetic mechanisms underlying DPD deficiency in patients presenting with grade III/IV 5FU-associated toxicity. In one patient a genomic DPYD deletion of exons 21–23 was observed. In five patients a deep intronic mutation c.1129–5923C>G was identified creating a cryptic splice donor site. As a consequence, a 44 bp fragment corresponding to nucleotides c.1129–5967 to c.1129–5924 of intron 10 was inserted in the mature DPD mRNA. The deleterious c.1129–5923C>G mutation proved to be in cis with three intronic polymorphisms (c.483 + 18G>A, c.959–51T>G, c.680 + 139G>A) and the synonymous mutation c.1236G>A of a previously identified haplotype. Retrospective analysis of 203 cancer patients showed that the c.1129–5923C>G mutation was significantly enriched in patients with severe 5FU-associated toxicity (9.1%) compared to patients without toxicity (2.2%). In addition, a high prevalence was observed for the c.1129–5923C>G mutation in the normal Dutch (2.6%) and German (3.3%) population. Our study demonstrates that a genomic deletion affecting DPYD and a deep intronic mutation affecting pre-mRNA splicing can cause severe 5FU-associated toxicity. We conclude that screening for DPD deficiency should include a search for genomic rearrangements and aberrant splicing.Electronic supplementary materialThe online version of this article (doi:10.1007/s00439-010-0879-3) contains supplementary material, which is available to authorized users.

Due to the lack of macromolecular fossils, the enzymatic repertoire of extinct species has remained largely unknown to date. In an attempt to solve this problem, we have characterized a cyclase subunit (HisF) of the imidazole glycerol phosphate synthase (ImGP-S), which was reconstructed from the era of the last universal common ancestor of cellular organisms (LUCA). As observed for contemporary HisF proteins, the crystal structure of LUCA-HisF adopts the (βα)8-barrel architecture, one of the most ancient folds. Moreover, LUCA-HisF (i) resembles extant HisF proteins with regard to internal 2-fold symmetry, active site residues, and a stabilizing salt bridge cluster, (ii) is thermostable and shows a folding mechanism similar to that of contemporary (βα)8-barrel enzymes, (iii) displays high catalytic activity, and (iv) forms a stable and functional complex with the glutaminase subunit (HisH) of an extant ImGP-S. Furthermore, we show that LUCA-HisF binds to a reconstructed LUCA-HisH protein with high affinity. Our findings suggest that the evolution of highly efficient enzymes and enzyme complexes has already been completed in the LUCA era, which means that sophisticated catalytic concepts such as substrate channeling and allosteric communication existed already 3.5 billion years ago.

Background Comprehensive geriatric assessment (CGA) has been in use for the last three decades. However, some doubts remain regarding its clinical use. Therefore, we aimed to capture the breadth of outcomes reported and assess the strength of evidence of the use of comprehensive geriatric assessment (CGA) for health outcomes in older persons. Methods Umbrella review of systematic reviews of the use of CGA in older adults searching in Pubmed, Embase, Scopus, Cochrane library and CINHAL until 05 November 2021. All possible health outcomes were eligible. Two independent reviewers extracted key data. The grading of evidence was carried out using the GRADE for intervention studies, whilst data regarding systematic reviews were reported as narrative findings. Results Among 1,683 papers, 31 systematic reviews (19 with meta-analysis) were considered, including 279,744 subjects. Overall, 13/53 outcomes were statistically significant (P < 0.05). There was high certainty of evidence that CGA reduces nursing home admission (risk ratio [RR] = 0.86; 95% confidence interval [CI]: 0.75–0.89), risk of falls (RR = 0.51; 95%CI: 0.29–0.89), and pressure sores (RR = 0.46; 95%CI: 0.24–0.89) in hospital medical setting; decreases the risk of delirium (OR = 0.71; 95%CI: 0.54–0.92) in hip fracture; decreases the risk of physical frailty in community-dwelling older adults (RR = 0.77; 95%CI: 0.64–0.93). Systematic reviews without meta-analysis indicate that CGA improves clinical outcomes in oncology, haematology, and in emergency department. Conclusions CGA seems to be beneficial in the hospital medical setting for multiple health outcomes, with a high certainty of evidence. The evidence of benefits is less strong for the use of CGA in other settings.

No abstract