Major Phenotype (major + phenotype)

Distribution by Scientific Domains


Selected Abstracts


An interplay of alleviating mutations in the clinical phenotype of ,-thalassaemia intermedia

INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 6 2004
A. NADKARNI
Summary Prediction of a , -thalassaemia major phenotype from the , -genotype is generally relatively straightforward. However, despite the ability to accurately define the , -thalassaemia mutations, prediction of a , -thalassaemia intermedia phenotype from the genotype sometimes remains problematic and this has important implications in genetic counselling and prenatal diagnosis. We report a 11-year-old Indian male child with a thalassaemia intermedia phenotype. , -Globin gene analysis of the family showed that he was a compound heterozygote with the ,88 (C,T) ,+ -mutation and the IVS1 nt 130 (G,C) ,0 -mutation. Both these mutations are rare among Indians. The propositus was also found to be heterozygous for the XmnI polymorphism and had a normal , -genotype. In this family interplay of two alleviating mutations (a milder promoter mutation along with a gene for raised HbF) might have synergistically compensated for lack of globin chains in the patient. Hence, the nature of the , -genotype as well as the knowledge of the presence or absence of alleviating factors will help the clinician to decide whether early commencement of a regular transfusion regime is necessary. [source]


Distinct C-terminus of the B subunit of factor XIII in a population-associated major phenotype: the first case of complete allele-specific alternative splicing products in the coagulation and fibrinolytic systems

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 7 2009
H. IWATA
Summary.,Objectives: The purpose of this study was to elucidate the molecular bases of the heterogeneity of the B subunit of coagulation factor XIII (FXIII-B), classified by isoelectric focusing into its three population-associated major phenotypes. Methods and Results: By genetic sequencing and polymerase chain reaction (PCR),restriction fragment length polymorphism analyses, a C-to-G change was identified in intron K for the Asian-associated major phenotype FXIII-B*3. A transcript containing the novel exon XII, was detected by reverse transcription PCR using hepatocyte cell lines with this allele. The exclusive existence of a novel C-terminal peptide in a homozygote of FXIII-B*3 was also detected by matrix-assisted laser-desorption ionization time of flight mass spectrometry. The FXIII-B*3 isoform had a C-terminus 15 residues longer than the other isoforms, containing two additional basic amino acids and one extra acidic amino acid. Accordingly, the C-to-G nucleotide substitution created an efficient splice acceptor AG dinucleotide, which resulted in allele-specific alternative splicing in intron K. When compared with FXIII-B*1, the third major phenotype, FXIII-B*2, had an A-to-G change in exon III, converting His95 to Arg, and a rare phenotype, FXIII-B*4, had an A-to-T change in exon VII, converting Glu368 to Val. Conclusions: We found an extremely rare event of complete allele-specific alternative splicing for FXIII-B. The FXIII-B*3 isoform had a distinct C-terminal peptide, while the FXIII-B*2 and FXIII-B*4 isoforms had His95 to Arg and Glu368 to Val substitutions, respectively, which led to differential isoelectric points of these isoforms. Such variations in the amino acid sequence of FXIII-B may have profound effects on its structure,function relationship, plasma FXIII levels, and disease susceptibility. [source]


A CDPK isoform participates in the regulation of nodule number in Medicago truncatula

THE PLANT JOURNAL, Issue 6 2006
Pablo R. Gargantini
Summary Medicago spp. are able to develop root nodules via symbiotic interaction with Sinorhizobium meliloti. Calcium-dependent protein kinases (CDPKs) are involved in various signalling pathways in plants, and we found that expression of MtCPK3, a CDPK isoform present in roots of the model legume Medicago truncatula, is regulated during the nodulation process. Early inductions were detected 15 min and 3,4 days post-inoculation (dpi). The very early induction of CPK3 messengers was also present in inoculated M. truncatuladmi mutants and in wild-type roots subjected to salt stress, indicating that this rapid response is probably stress-related. In contrast, the later response was concomitant with cortical cell division and the formation of nodule primordia, and was not observed in wild-type roots inoculated with nod,, strains. This late induction correlated with a change in the subcellular distribution of CDPK activities. Accordingly, an anti- MtCPK3 antibody detected two bands in soluble root extracts and one in the particulate fraction. CPK3::GFP fusions are targeted to the plasma membrane in epidermal onion cells, a localization that depends on myristoylation and palmitoylation sites of the protein, suggesting a dual subcellular localization. MtCPK3 mRNA and protein were also up-regulated by cytokinin treatment, a hormone linked to the regulation of cortical cell division and other nodulation-related responses. An RNAi-CDPK construction was used to silence CPK3 in Agrobacterium rhizogenes -transformed roots. Although no major phenotype was detected in these roots, when infected with rhizobia, the total number of nodules was, on average, twofold higher than in controls. This correlates with the lack of MtCPK3 induction in the inoculated super-nodulator sunn mutant. Our results suggest that CPK3 participates in the regulation of the symbiotic interaction. [source]


Molecular characterization of novel progranulin (GRN) mutations in frontotemporal dementia,

HUMAN MUTATION, Issue 4 2008
Odity Mukherjee
Abstract Frontotemporal dementia (FTD) is a clinical term encompassing dementia characterized by the presence of two major phenotypes: 1) behavioral and personality disorder, and 2) language disorder, which includes primary progressive aphasia and semantic dementia. Recently, the gene for familial frontotemporal lobar degeneration (FTLD) with ubiquitin-positive, tau-negative inclusions (FTLD-U) linked to chromosome 17 was cloned. In the present study, 62 unrelated patients from the Washington University Alzheimer's Disease Research Center and the Midwest Consortium for FTD with clinically diagnosed FTD and/or neuropathologically characterized cases of FTLD-U with or without motor neuron disease (MND) were screened for mutations in the progranulin gene (GRN; also PGRN). We discovered two pathogenic mutations in four families: 1) a single-base substitution within the 3, splice acceptor site of intron 6/exon 7 (g.5913A>G [IVS6,2A>G]) causing skipping of exon 7 and premature termination of the coding sequence (PTC); and 2) a missense mutation in exon 1 (g.4068C>A) introducing a charged amino acid in the hydrophobic core of the signal peptide at residue 9 (p.A9D). Functional analysis in mutation carriers for the splice acceptor site mutation revealed a 50% decrease in GRN mRNA and protein levels, supporting haploinsufficiency. In contrast, there was no significant difference in the total GRN mRNA between cases and controls carrying the p.A9D mutation. Further, subcellular fractionation and confocal microscopy indicate that although the mutant protein is expressed, it is not secreted, and appears to be trapped within an intracellular compartment, possibly resulting in a functional haploinsufficiency. Hum Mutat 29(4), 512,521, 2008. 2008 Wiley-Liss, Inc. [source]


Distinct C-terminus of the B subunit of factor XIII in a population-associated major phenotype: the first case of complete allele-specific alternative splicing products in the coagulation and fibrinolytic systems

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 7 2009
H. IWATA
Summary.,Objectives: The purpose of this study was to elucidate the molecular bases of the heterogeneity of the B subunit of coagulation factor XIII (FXIII-B), classified by isoelectric focusing into its three population-associated major phenotypes. Methods and Results: By genetic sequencing and polymerase chain reaction (PCR),restriction fragment length polymorphism analyses, a C-to-G change was identified in intron K for the Asian-associated major phenotype FXIII-B*3. A transcript containing the novel exon XII, was detected by reverse transcription PCR using hepatocyte cell lines with this allele. The exclusive existence of a novel C-terminal peptide in a homozygote of FXIII-B*3 was also detected by matrix-assisted laser-desorption ionization time of flight mass spectrometry. The FXIII-B*3 isoform had a C-terminus 15 residues longer than the other isoforms, containing two additional basic amino acids and one extra acidic amino acid. Accordingly, the C-to-G nucleotide substitution created an efficient splice acceptor AG dinucleotide, which resulted in allele-specific alternative splicing in intron K. When compared with FXIII-B*1, the third major phenotype, FXIII-B*2, had an A-to-G change in exon III, converting His95 to Arg, and a rare phenotype, FXIII-B*4, had an A-to-T change in exon VII, converting Glu368 to Val. Conclusions: We found an extremely rare event of complete allele-specific alternative splicing for FXIII-B. The FXIII-B*3 isoform had a distinct C-terminal peptide, while the FXIII-B*2 and FXIII-B*4 isoforms had His95 to Arg and Glu368 to Val substitutions, respectively, which led to differential isoelectric points of these isoforms. Such variations in the amino acid sequence of FXIII-B may have profound effects on its structure,function relationship, plasma FXIII levels, and disease susceptibility. [source]