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Atypical Phenotype (atypical + phenotype)

Distribution by Scientific Domains

Medical Sciences	50%
Life Sciences	50%

Selected Abstracts

Clinical and genetic heterogeneity in Omenn syndrome and severe combined immune deficiency

PEDIATRIC TRANSPLANTATION, Issue 2 2009
Tanja A. Gruber
Abstract:, OS has been described as a clinical phenotype in infants characterized by SCID, diffuse erythroderma, and other distinct features. The pathogenesis is secondary to autologous, auto-reactive T cells produced as rare escapees from the SCID blockade. Mutations in either the RAG1 or RAG2 gene that lead to partial recombinase activity are responsible for many of the patients with these clinical features. We report on two patients, one with an atypical phenotype of OS (absence of rash but presence of other typical features) who harbored a previously undescribed mutation in RAG1, and a second who had many of the classic features of OS but was found to have a mutation in the common gamma chain (,c) cytokine receptor gene. These cases highlight the clinical and genetic heterogeneity of OS. [source]

Extended diagnostic criteria for plasmacytoid dendritic cell leukaemia

BRITISH JOURNAL OF HAEMATOLOGY, Issue 5 2009
Francine Garnache-Ottou
Summary The diagnosis of plasmacytoid dendritic cell leukaemia (pDCL) is based on the immunophenotypic profile: CD4+ CD56+ lineageneg CD45RA+/ROneg CD11cneg CD116low CD123+ CD34neg CD36+ HLA-DR+. Several studies have reported pDCL cases that do not express this exact profile or expressing some lineage antigens that could thus be misdiagnosed. This study aimed to validate pDCL-specific markers for diagnosis by flow-cytometry or quantitative reverse transcription polymerase chain reaction on bone marrow samples. Expression of markers previously found in normal pDC was analysed in 16 pDCL, four pDCL presenting an atypical phenotype (apDCL) and 113 non-pDC , lymphoid or myeloid , acute leukaemia. CD123 was expressed at significantly higher levels in pDCL and apDCL. BDCA-2 was expressed on 12/16 pDCL and on 2/4 apDCL, but was never detected in the 113 non-pDC acute leukaemia cases. BDCA-4 expression was found on 13/16 pDCL, but also in 12% of non-pDC acute leukaemia. High levels of LILRA4 and TCL1A transcripts distinguished pDCL and apDCL from all other acute leukaemia (except B-cell acute lymphoblastic leukaemia for TCL1A). We thus propose a diagnosis strategy, scoring first the CD4+ CD56+/, MPOneg cCD3neg cCD79aneg CD11cneg profile and then the CD123high, BDCA-2 and BDCA-4 expression. Atypical pDCL can be also identified this way and non-pDC acute leukaemia excluded: this scoring strategy is useful for diagnosing pDCL and apDCL. [source]

ZFHX1B mutations in patients with Mowat-Wilson syndrome,

HUMAN MUTATION, Issue 4 2007
Florence Dastot-Le Moal
Abstract Mowat-Wilson syndrome (MWS) is a recently delineated mental retardation (MR)-multiple congenital anomaly syndrome, characterized by typical facies, severe MR, epilepsy, and variable congenital malformations, including Hirschsprung disease (HSCR), genital anomalies, congenital heart disease (CHD), and agenesis of the corpus callosum (ACC). It is caused by de novo heterozygous mutations or deletions of the ZFHX1B gene located at 2q22. ZFHX1B encodes Smad-interacting protein-1 (SMADIP1 or SIP1), a transcriptional corepressor involved in the transforming growth factor-, signaling pathway. It is a highly evolutionarily conserved gene, widely expressed in embryological development. Over 100 mutations have been described in patients with clinically typical MWS, who almost always have whole gene deletions or truncating mutations (nonsense or frameshift) of ZFHX1B, suggesting that haploinsufficiency is the basis of MWS pathology. No obvious genotype,phenotype correlation could be identified so far, but atypical phenotypes have been reported with missense or splice mutations in the ZFHX1B gene. In this work we describe 40 novel mutations and we summarize the various mutational reports published since the identification of the causative gene. Hum Mutat 28(4), 313,321, 2007. © 2007 Wiley-Liss, Inc. [source]

Comparison of methods for the detection of methicillin resistance in Staphylococcus aureus isolates from food products

LETTERS IN APPLIED MICROBIOLOGY, Issue 5 2007
M. Corrente
Abstract Aims:, To compare several methods for detection of methicillin resistance in Staphylococcus aureus isolates from food. Methods and Results:, Two hundred S. aureus isolates from food of animal origin were screened for methicillin resistance by a PCR assay specific for the mecA gene, an oxacillin agar screen test and a cefoxitin disk diffusion test. Six out of 200 strains (3%) were found to be methicillin-resistant Staphylococcus aureus (MRSA) by PCR. The oxacillin agar screen test detected only one of the MRSA isolates (sensitivity of 16·7%) and mischaracterized three additional strains as MRSA (specificity of 98·45%). None of the MRSA strains was detected by the cefoxitin test (sensitivity of 0%), while 15 methicillin-susceptible S. aureus (MSSA) strains were misclassified as resistant (specificity of 92·3%). Fifteen MSSA strains displayed a ,-lactamase hyperproducer-like phenotype. The six MRSA (mecA-positive) strains resembled the characteristics of heteroresistant strains. Conclusions:, As MRSA of animal origin may display atypical phenotypes, PCR appears to be more reliable for detection of methicillin resistance in animal strains. Significance and Impact of the Study:, The study stresses the need for implementing the methods of screening S. aureus from food of animal origin for methicillin resistance. [source]