RESUMO
Serial quantification of BCR-ABL1 mRNA is an important therapeutic indicator in chronic myeloid leukaemia, but there is a substantial variation in results reported by different laboratories. To improve comparability, an internationally accepted plasmid certified reference material (CRM) was developed according to ISO Guide 34:2009. Fragments of BCR-ABL1 (e14a2 mRNA fusion), BCR and GUSB transcripts were amplified and cloned into pUC18 to yield plasmid pIRMM0099. Six different linearised plasmid solutions were produced with the following copy number concentrations, assigned by digital PCR, and expanded uncertainties: 1.08±0.13 × 10(6), 1.08±0.11 × 10(5), 1.03±0.10 × 10(4), 1.02±0.09 × 10(3), 1.04±0.10 × 10(2) and 10.0±1.5 copies/µl. The certification of the material for the number of specific DNA fragments per plasmid, copy number concentration of the plasmid solutions and the assessment of inter-unit heterogeneity and stability were performed according to ISO Guide 35:2006. Two suitability studies performed by 63 BCR-ABL1 testing laboratories demonstrated that this set of 6 plasmid CRMs can help to standardise a number of measured transcripts of e14a2 BCR-ABL1 and three control genes (ABL1, BCR and GUSB). The set of six plasmid CRMs is distributed worldwide by the Institute for Reference Materials and Measurements (Belgium) and its authorised distributors (https://ec.europa.eu/jrc/en/reference-materials/catalogue/; CRM code ERM-AD623a-f).
Assuntos
Proteínas de Fusão bcr-abl/genética , Proteínas de Fusão bcr-abl/metabolismo , Plasmídeos/genética , Reação em Cadeia da Polimerase em Tempo Real/normas , Calibragem , Clonagem Molecular , DNA , Proteínas de Escherichia coli/genética , Dosagem de Genes , Humanos , Proteínas de Membrana Transportadoras/genética , Proteínas Proto-Oncogênicas c-bcr/genética , RNA Mensageiro/metabolismo , Padrões de ReferênciaRESUMO
This report describes a rare case of a patient with increased urinary dopamine excretion in association with bilateral carotid body tumours. Excretion of adrenaline, noradrenaline, metadrenaline, normetadrenaline and 4-hydroxy-3-methoxymandelic acid (HMMA) were within the reference ranges, and an (123)I-meta-iodobenzylguanidine (MIBG) scan showed uptake in the neck masses, with no other abnormal uptake anywhere else in the body. The patient is being managed conservatively as the tumours are not amenable to resection on account of their size and vascularity. There are only four previous case reports of dopamine-secreting tumours of the carotid body described in the literature, all of whom were women. The tumours were unilateral in three cases and bilateral in the fourth case. Familial cases of carotid body tumours have a higher prevalence of bilateral tumours than non-familial cases. Recent reports in the literature have suggested that a significant number of patients with extra-adrenal catecholamine-secreting paragangliomas have a genetic mutation in one of the identified susceptibility genes for catecholamine-secreting tumours, despite having no other affected family members, and a mutation has been found in the succinate dehydrogenase gene for this patient.