Cytogenet Genome Res.

We report on a currently six-year-old patient with a de novo complex chromosome rearrangement (CCR) involving chromosomes 2 and 12. A translocation 2;12 that appeared to be reciprocal after standard banding turned out to be a complex event with seven breaks after molecular cytogenetic analyses. Array CGH analysis showed no imbalances at the breakpoints but revealed an additional microdeletion of about 80 kb on chromosome 11. The same deletion was also present in the phenotypically normal father. The patient showed relatively mild mental retardation, defined mainly as impaired speech development (orofacial dyspraxia) and psychomotor retardation. In addition, mild dysmorphic facial features like hypertelorism, a prominent philtrum and down-turned corners of the mouth were observed. We narrowed down all breakpoint regions to about 100 kb, using a panel of mapped bacterial artificial chromosome (BAC) clones for fluorescence in situ hybridization (FISH). BACs spanning or flanking all seven breakpoints were identified and no chromosomal imbalances were found consistent with the array CGH results. Our investigations resulted in the following karyotype: 46,XY,t(2;12)(2pterrarr2p25.3::2p23.3rarr2p25.2::2p23.3rarr2p14::2q14.3rarr2p14::2q14.3rarr2q14.3::12q 12rarr12qter;12pterrarr12q12::2p25.3rarr2p25.2::2q14.3rarr2qter)

Phenomenological investigation of sodium boiling in a SFR core during a postulated ULOF transient with CATHARE 2 system code: a stabilized boiling case

International audienceIn the framework of the research and development on GEN IV sodium fast reactors (SFRs), the phenomenology of sodium boiling during a postulated unprotected loss of flow (ULOF) transient has been investigated with the CATHARE 2 system code. This study focuses on a stabilized boiling case: in such a regime, no flow redistribution occurs from the subassemblies which have reached the saturation temperature to those that are still single-phase. In this paper, for a subassembly design featuring no restrictive structures above the fuel bundle, a quasi-static approach is first developed to get an upper bound of the reactor core power at boiling onset that would be compatible with the well-known Ledinegg criteria for diphasicflowstaticequilibrium.Then,dynamicsresultsachievedthroughsimulationwiththeCATHARE 2 code for a postulated ULOF are presented: boiling is shown to remain stable during the transient for such a core power at boiling onset. Another important outcome of the simulation is the calculation of a dynamic instability, in the form of a two-phase hydrodynamic chugging phenomenon. The predicted phenomenology of this stabilized boiling case should be studied further in order to consider its dependency on the underlying closure laws and to eliminate the possibility of a numerical instability