[Toward pertinent analytical objectives for haematological parameters]. / Vers les objectifs analytiques pertinents pour les paramètres de l'hémogramme.

Usually, the blood cell counting activity in haematology laboratory uses the comparison of IQC values to the target values proposed by the manufacturer. We intended to improve the monitoring of the proper functioning of our analytical measure system for 17 main haematologic parameters. To set the allowable critical limits of IQC, we propose our reflection based on several elements: benchmark and expert recommendation, clinical requirements, statistical indicators of the laboratory calculated using IQC values (3 levels, 2 different lots, 2 haematology analysers and 2 passage modes) and the EEQ values, during four months. We exploited the reports obtained from the middleware (our own IQC values), and the interlaboratory comparison reports (obtained from SNCS and EuroCell websites) and we compared our performances to the Ricos objectives, to set clearly argued allowable limits for IQC values. Finally, the allowable limits correspond to the imprecision limits stated by Ricos for 14 parameters (desirable for 11 parametres and minimal for 3 parameters) and personalized limits (more exigent than desirable Ricos limits) for 3 parameters of blood cell counting.

Characterization of a 7.6-Mb germline deletion encompassing the NF1 locus and about a hundred genes in an NF1 contiguous gene syndrome patient.

We describe a large germline deletion removing the NF1 locus, identified by heterozygosity mapping based on microsatellite markers, in an 8-year-old French girl with a particularly severe NF1 contiguous gene syndrome. We used gene-dose mapping with sequence-tagged site real-time PCR to locate the deletion end points, which were precisely characterized by means of long-range PCR and nucleotide sequencing. The deletion is located on chromosome arm 17q and is exactly 7 586 986 bp long. It encompasses the entire NF1 locus and about 100 other genes, including numerous chemokine genes, an attractive in silico-selected cerebrally expressed candidate gene (designated NUFIP2, for nuclear fragile X mental retardation protein interacting protein 2; NM_020772) and four microRNA genes. Interestingly, the centromeric breakpoint is located in intron 4 of the PIPOX gene (pipecolic acid oxidase; NM_016518) and the telomeric breakpoint in intron 5 of the GGNBP2 gene (gametogenetin binding protein 2; NM_024835) coding a transcription factor. As PIPOX and GGNBP2 have the same transcriptional orientation, we postulated, and then confirmed, the existence of a chimeric transcript. This transcript, and/or haploinsufficiency of one or several deleted genes, could explain the clinical severity of the syndrome in this patient.