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Fulltext Dengue virus type 2 envelope protein displayed as recombinant phage attachment protein reveals potential cell binding sites

Abd-Jamil J, Cheah CY, AbuBakar S

Protein Eng. Des. Sel., 2008 Oct;21(10):605-11.
PMID: 18669522 DOI: 10.1093/protein/gzn041

A method to map the specific site on dengue virus envelope protein (E) that interacts with cells and a neutralizing antibody is developed using serially truncated dengue virus type 2 (DENV-2) E displayed on M13 phages as recombinant E-g3p fusion proteins. Recombinant phages displaying the truncated E consisting of amino acids 297-423 (EB2) and amino acids 379-423 (EB4) were neutralized by DENV-2 patient sera and the DENV-2 E-specific 3H5-1 monoclonal antibodies suggesting that the phages retained the DENV-2 E antigenic properties. The EB4 followed by EB2 recombinant phages bound the most to human monocytes (THP-1), African green monkey kidney (Vero) cells, mosquito (C6/36) cells, ScFv specific against E and C6/36 cell proteins. Two potential cell attachment sites were mapped to loop I (amino acids 297 to 312) and loop II (amino acids 379-385) of the DENV-2 E using the phage-displayed truncated DENV-2 E fragments and by the analysis of the E structure. Loop II was present only in EB4 recombinant phages. There was no competition for binding to C6/36 cell proteins between EB2 and EB4 phages. Loop I and loop II are similar to the sub-complex specific and type-specific neutralizing monoclonal antibody binding sites, respectively. Hence, it is proposed that binding and entry of DENV involves the interaction of loop I to cell surface glycosaminoglycan-motif and a subsequent highly specific interaction involving loop II with other cell proteins. The phage displayed truncated DENV-2 E is a powerful and useful method for the direct determination of DENV-2 E cell binding sites.

Matched MeSH terms: Gene Deletion
Fulltext Two cases of deletion 5p syndrome: one with paternal involvement and another with atypical presentation

Azman BZ, Akhir SM, Zilfalil BA, Ankathil R

Singapore Med J, 2008 Apr;49(4):e98-e100.
PMID: 18418516

We report two cases of deletion 5p or cri du chat syndrome (CdCS) with different presentations and risks of transmission: one case with paternal chromosome 5 involvement and another, a de novo case with atypical clinical presentation. Cytogenetic analysis was performed on the two cases and their parents. GTG-banded karyotype analysis of Cases 1 and 2 revealed abnormal 46,XY,del(5)(p13-15) male karyotypes. For Case 1, the mother showed normal female karyotype while the father showed an abnormal karyotype involving a balanced translocation 46,XY,t(5;10)(p13;p15). For Case 2, however, both parents showed a normal karyotype pattern. In Case 1, the clinical features, particularly the distinct facial phenotype in combination with a characteristic cat-like cry and hypotonia, aided in the diagnosis at birth and the karyotype analysis was resolutive. The boy in Case 2 presented with atypical clinical features. Even though this patient had multiple syndromic features, the typical high pitched cat-like cry was not prominent. Instead, the patient manifested persistent stridor (from day three of life), which might have prevented the clinician from suspecting CdCS at birth. However, when this patient was presented at seven months of age for cytogenetic analysis, a confirmatory diagnosis of CdCS was established. For children with congenital abnormalities, an early clinical diagnosis confirmed through cytogenetic and molecular investigations, is important for providing personalised diagnostic and prognostic evaluation, and also for genetic counselling on the reproductive risk, particularly for patients with parental chromosome translocation involvement.

Matched MeSH terms: Gene Deletion
Fulltext Detection of gene deletions by PCR analysis in a Malaysian patient with Duchenne muscular dystrophy

Lee MK, Manonmani V, Arahata K

Med J Malaysia, 1993 Mar;48(1):46-50.
PMID: 8341171

Duchenne muscular dystrophy (DMD), the commonest X-linked disorder, is a progressive, eventually fatal disease. With the advent of molecular genetics, the Duchenne gene and its protein product, dystrophin, have been characterised. Molecular diagnosis of DMD, identification of carriers and antenatal diagnosis are now possible. We describe here the use, in a Malaysian boy with DMD, of a recent innovation, multiplex polymerase chain reaction (PCR), to obtain molecular diagnosis by detection of dystrophin gene deletions.

Matched MeSH terms: Gene Deletion*
Fulltext GATA1 mutations in a cohort of Malaysian children with Down syndrome-associated myeloid disorder

Lum SH, Choong SS, Krishnan S, Mohamed Z, Ariffin H

Singapore Med J, 2016 Jun;57(6):320-4.
PMID: 27353457 DOI: 10.11622/smedj.2016106

INTRODUCTION: Children with Down syndrome (DS) are at increased risk of developing distinctive clonal myeloid disorders, including transient abnormal myelopoiesis (TAM) and myeloid leukaemia of DS (ML-DS). TAM connotes a spontaneously resolving congenital myeloproliferative state observed in 10%-20% of DS newborns. Following varying intervals of apparent remission, a proportion of children with TAM progress to develop ML-DS in early childhood. Therefore, TAM and ML-DS represent a biological continuum. Both disorders are characterised by recurring truncating somatic mutations of the GATA1 gene, which are considered key pathogenetic events.
METHODS: We herein report, to our knowledge, the first observation on the frequency and nature of GATA1 gene mutations in a cohort of Malaysian children with DS-associated TAM (n = 9) and ML-DS (n = 24) encountered successively over a period of five years at a national referral centre.
RESULTS: Of the 29 patients who underwent GATA1 analysis, GATA1 mutations were observed in 15 (51.7%) patients, including 6 (75.0%) out of 8 patients with TAM, and 9 (42.9%) of 21 patients with ML-DS. All identified mutations were located in exon 2 and the majority were sequence-terminating insertions or deletions (66.7%), including several hitherto unreported mutations (12 out of 15).
CONCLUSION: The low frequency of GATA1 mutations in ML-DS patients is unusual and potentially indicates distinctive genomic events in our patient cohort.

Matched MeSH terms: Gene Deletion
NAIP-deletion analysis in Malaysian patients with spinal muscular atrophy

Watihayati MS, M S W, Zabidi AM, A M H ZH, Tang TH, T H T, et al.

Kobe J Med Sci, 2007;53(4):171-5.
PMID: 17932457

Spinal Muscular Atrophy (SMA) is an autosomal recessive disease, which is characterized by degeneration of the anterior horn cells of the spinal cord. SMA is classified into 3 clinical subtypes, type I (severe), type II (intermediate), and type III (mild). Two genes, SMN1 and NAIP, have been identified as SMA-related genes. The SMN1 gene is now recognized as a responsible gene for the disease because it is deleted or mutated in most SMA patients. However, the role of the NAIP gene in SMA has not been fully clarified. To clarify the contribution of NAIP to the disease severity of SMA, we studied the relationship between NAIP-deletion and clinical phenotype in Malaysian patients. A total of 39 patients lacking SMN1 (12 type I, 19 type II, and 8 type III patients) were enrolled into this study. Seven out of 12 patients with type I SMA (approximately 60%) showed NAIP deletion. On the contrary, only 2 out of 20 type II patients and none of type III patients showed NAIP deletion. There was a statistically significant difference in NAIP-deletion frequency among the clinical subtypes (Fisher's exact probability test, p value = 0.014). In conclusion, according to our data that NAIP deletion was more frequent in type I SMA than in type II-III SMA, the NAIP gene may be a modifying factor for disease severity of SMA.

Matched MeSH terms: Gene Deletion*
RecA mediated spontaneous deletions of the icaADBC operon of clinical Staphylococcus epidermidis isolates: a new mechanism of phenotypic variations

Nuryastuti T, Henny C, Henk JB, Roel K, Abu TA, Bastiaan PK

Med J Malaysia, 2008 Jul;63 Suppl A:97.
PMID: 19025002

Phenotypic variation in biofilm formation is common in clinical isolates of S. epidermidis. In the current study, nearly 5% of all clinical isolates analysed showed phenotypic variation in biofilm forming ability and electrophoretic mobility (EM). This is the first report of S. epidermidis strains irreversibly switching from biofilm-positive to biofilm-negative phenotype by spontaneous deletion of icaADBC genes which represents a new, possibly common mechanism of phenotypic variation.

Matched MeSH terms: Gene Deletion*
Mitochondrial disorder, diabetes mellitus, and findings in three muscles, including the heart

Bhattacharjee M, Venugopal B, Wong KT, Goto YI, Bhattacharjee MB

Ultrastruct Pathol, 2006 Nov-Dec;30(6):481-7.
PMID: 17183762

The authors describe the case of a 50-year-old man with chronic progressive external ophthalmoplegia (CPEO), diabetes mellitus (DM), and coronary artery disease. The patient had no cardiac conduction abnormalities. During coronary artery bypass surgery, his heart and two skeletal muscles were biopsied. All three muscles showed ragged red fibers. The heart muscle showed significant glycogen accumulation. Analysis of mitochondrial DNA (mtDNA) showed a 5019-base-pair deletion, with no duplications. There were morphologically abnormal mitochondria in all 3 muscles, with clinically apparent difference in preservation of function. The combination of diabetes mellitus and mtDNA deletion is fortuitous, as they can be causally linked. The cardiac pathology allows speculation about the possible adaptive processes that may occur in the heart in DM. There are few reported cases with CPEO and excess glycogen in the heart. Most show deposition of fat and poorer clinical outcomes as compared to those with glycogen deposition. This observation may lend support to the hypothesis that in the myocardium, adaptive responses are mediated via changes in glucose handling, whereas alterations in fat metabolism likely represent maladaptation.

Matched MeSH terms: Gene Deletion
Higher failures of amelogenin sex test in an Indian population group

Chang YM, Burgoyne LA, Both K

J Forensic Sci, 2003 Nov;48(6):1309-13.
PMID: 14640276

The human sex test in forensic multiplexes is based on the amelogenin gene on both the X and Y chromosomes commonly used in sex genotyping. In this study of 338 male individuals in a Malaysian population comprising Malays, Chinese and Indians, using the AmpFlSTR Profiler Plus kit, the amelogenin test gave a significant proportion of null alleles in the Indian ethnic group (3.6% frequency) and 0.88% frequency in the Malay ethnic group due to a deletion of the gene on the Y chromosome. This sex test also failed in a forensic casework sample. Failure of the amelogenin test highlights the need for more reliable sex determination than is offered by the amelogenin locus in the Malay and Indian populations. The gender of the Indian-Malay amelogenin nulls was confirmed by the presence of three Y-STR alleles (DYS438, DYS390 and DYS439). For the Indian ethnic group, one of the Y-STR forms a stable haplotype with the amelogenin null. The amelogenin-deletion individuals also showed a null with a male-specific minisatellite MSY1, indicating that a very large deletion was involved that included the amelogenin and the MSY1 loci on the short arm of the Y chromosomes (Yp).

Matched MeSH terms: Gene Deletion
HPV infection and the alterations of the pRB pathway in oral carcinogenesis

Lim KP, Hamid S, Lau SH, Teo SH, Cheong SC

Oncol Rep, 2007 Jun;17(6):1321-6.
PMID: 17487385 DOI: 10.3892/or.17.6.1321

Inactivation of the retinoblastoma (pRB) pathway is a common event in oral squamous cell carcinoma particularly through the aberrant expression of the components within this pathway. This study examines the alterations of molecules within the pRB pathway by looking at the presence of homozygous deletions in p16(INK4A) and the expression patterns of pRB, cyclin D1 and CDK4, as well as the presence of human papillomavirus (HPV) in our samples. In our study, 5/20 samples demonstrated deletions of p16(INK4A) exon 1alpha. pRB overexpression was found in 20/20 samples, the expression was mainly observed in all layers of the epithelia, particularly in the basal layer where cells are actively dividing and aberrant pRB expression was found in 12/20 samples. Cyclin D1 and CDK4 overexpression was detected in 6/20 and 2/20 samples respectively in comparison to hyperplasias where both proteins were either not expressed or expressed at minimal levels (<10%). Strikingly, HPV was found to be present in all of our samples, suggesting that HPV plays a significant role in driving oral carcinogenesis. Notably, 17/20 of our samples showed more than one alteration in the pRB pathway, however, we did not find any significant relationship between the presence of HPV, homozygous deletion of p16(INK4A) and overexpression of pRB, cyclin D1 and CDK4. Collectively, this data demonstrates that alterations in the pRB pathway are a common event and involve the aberration of more than one molecule within the pathway. Furthermore, the involvement of HPV in all our samples suggests that HPV infection may play an important role in oral carcinogenesis.

Matched MeSH terms: Gene Deletion
Alterations of the p14ARF-p53-MDM2 pathway in oral squamous cell carcinoma: MDM2 overexpression is a common event

Lim KP, Sharifah H, Lau SH, Teo SH, Cheong SC

Oncol Rep, 2005 Oct;14(4):963-8.
PMID: 16142358 DOI: 10.3892/or.14.4.963

The majority of global incidences of oral cancer occur in Asia, and the aetiology of oral cancer is different in Asia as it is in the West. However, whereas there is a growing understanding of the molecular mechanisms of oral cancer progression in the West, there is little progress in this understanding in Asia. In particular, the role of the p53 pathway in modulating cancer progression in Asian oral cancer remains unclear. In this study, we micro-dissected and analysed 20 well-differentiated oral squamous cell carcinoma specimens for alterations in the p53 pathway. We found that 6/20 samples contained mutations in the p53 gene which occurred in three hotspots, at codon 203, 218 and 296. Furthermore, 6/20 samples had a homozygous deletion of p14ARF, but notably p14ARF deletion and p53 mutation events were often independent and mutually exclusive. Strikingly, MDM2 was upregulated in 20/20 samples, but not in 3/3 normal tissue specimens. Taken together, these data suggest that inactivation of the p53 pathway is a frequent event in oral squamous cell carcinoma, which occurs by an aberration in one of a number of players in the p53 pathway.

Matched MeSH terms: Gene Deletion
Transcriptome profiling of endothelial cells during infections with high and low densities of C. albicans cells

Lim CS, Rosli R, Seow HF, Chong PP

Int J Med Microbiol, 2011 Aug;301(6):536-46.
PMID: 21371935 DOI: 10.1016/j.ijmm.2010.12.002

Systemic infections of Candida albicans, the most prevalent fungal pathogen in humans, are on the rise in recent years. However, the exact mode of pathogenesis of this fungus is still not well elucidated. Previous studies using C. albicans mutants locked into the yeast form via gene deletion found that this form was avirulent and did not induce significant differential expression of host genes in vitro. In this study, a high density of C. albicans was used to infect human umbilical vein endothelial cells (HUVEC), resulting in yeast-form infections, whilst a low density of C. albicans resulted in hyphae infections. Transcriptional profiling of HUVEC response to these infections showed that high densities of C. albicans induced a stronger, broader transcriptional response from HUVEC than low densities of C. albicans infection. Many of the genes that were significantly differentially expressed were involved in apoptosis and cell death. In addition, conditioned media from the high-density infections caused a significant reduction in HUVEC viability, suggesting that certain molecules released during C. albicans and HUVEC interactions were capable of causing cell death. This study has shown that C. albicans yeast-forms, at high densities, cannot be dismissed as avirulent, but instead could possibly contribute to C. albicans pathogenesis.

Matched MeSH terms: Gene Deletion
Generation of monoclonal antibodies against Hong Kong nasopharyngeal carcinoma-associated Epstein-Barr virus latent membrane protein 1 (LMP1)

Chan BC, To KF, Pang JC, Chung YF, Lo KW, Tong JH, et al.

Int J Cancer, 2002 Dec 10;102(5):492-8.
PMID: 12432552

A panel of monoclonal antibodies specific to Hong Kong Chinese nasopharyngeal carcinoma (NPC)-associated Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) variants has been generated. These monoclonal antibodies not only differentiate the Hong Kong Chinese NPC-associated LMP1 variants from the prototype B95-8 LMP1, derived from Caucasian infectious mononucleosis, but also differentiate the 2 highly homologous LMP1 deletion variants commonly found in Hong Kong primary NPC. The predominant deletion type variant, DV-Asp335, is characterized by an aspartic acid at residue 335 located in the cytoplasmic C-terminal region, whereas the other minor deletion variant, DV-Gly335, has a glycine in the same residue position. 335D is hitherto found predominantly in LMP1 of the China 1 strain in association with NPC in the Chinese populations located in southern China and Malaysia. These antibodies, which are applicable in ELISA, immunofluorescence, immunoprecipitation, immunoblotting and immunohistochemistry on paraffin sections, are the first variant-specific anti-LMP1 monoclonal antibodies produced, and will be useful in investigating the functional significance of 335D in NPC.

Matched MeSH terms: Gene Deletion
Fulltext Plasmodium falciparum isolate with histidine-rich protein 2 gene deletion from Nyala City, Western Sudan

Boush MA, Djibrine MA, Mussa A, Talib M, Maki A, Mohammed A, et al.

Sci Rep, 2020 07 30;10(1):12822.
PMID: 32733079 DOI: 10.1038/s41598-020-69756-8

In remote areas of malaria-endemic countries, rapid diagnostic tests (RDTs) have dramatically improved parasitological confirmation of suspected malaria cases, especially when skilled microscopists are not available. This study was designed to determine the frequency of Plasmodium falciparum isolates with histidine-rich protein 2 (pfhrp2) gene deletion as one of the possible factors contributing to the failure of PfHRP2-based RDTs in detecting malaria. A total of 300 blood samples were collected from several health centres in Nyala City, Western Sudan. The performance of PfHRP2-based RDTs in relation to microscopy was examined and the PCR-confirmed samples were investigated for the presence of pfhrp2 gene. A total of 113 out of 300 patients were P. falciparum positive by microscopy. Among them, 93.81% (106 out of 113) were positives by the PfHRP2 RDTs. Seven isolates were identified as false negative on the basis of the RDTs results. Only one isolate (0.9%; 1/113) potentially has pfhrp2 gene deletion. The sensitivity and specificity of PfHRP2-based RDTs were 93.81% and 100%, respectively. The results provide insights into the pfhrp2 gene deletion amongst P. falciparum population from Sudan. However, further studies with a large and systematic collection from different geographical settings across the country are needed.

Matched MeSH terms: Gene Deletion*
G6PD deficiency with hemolytic anemia due to a rare gene deletion--a report of the first case in Malaysia

Ainoon O, Boo NY, Yu YH, Cheong SK, Hamidah HN

Hematology, 2006 Apr;11(2):113-8.
PMID: 16753852 DOI: 10.1080/10245330500155184

A 2-year-old Chinese boy was referred to Hospital UKM for investigation of recurrent episodes of dark-coloured urine and pallor since birth. He was born prematurely at 34 weeks gestation and developed severe early-onset neonatal jaundice requiring exchange blood transfusion. Screening at birth showed Glucose-6-phosphate dehydrogenase (G6PD) deficiency. On admission, physical examination revealed pallor, jaundice and mild hepatomegaly. Results of laboratory investigations showed a hemoglobin level of 11.0 g/dl with a hemolytic blood picture, reticulocytosis of 20% and red cell G6PD activity reported as undetectable. The patient's DNA was analysed for G6PD mutations by PCR-based techniques and DNA sequencing and results showed a 24 bp deletion of nucleotide 953-976 in the exon 9 of the G6PD gene. DNA analysis was also performed on blood samples of the patient's mother and female sibling confirming their heterozygous status, although both showed normal red cell G6PD activity levels. The patient was discharged well and his parents were appropriately advised on the condition and the importance of taking folic acid regularly. This is a first case report in Malaysia of G6PD deficiency causing chronic-hemolytic anemia. The rare 24 bp deletion causes the G6PD Nara variant, previously reported only in two other unrelated males, a Japanese and a Portuguese both with chronic hemolytic anemia.

Matched MeSH terms: Gene Deletion*
Identification of novel extracellular protein for PCB/biphenyl metabolism in Rhodococcus jostii RHA1

Atago Y, Shimodaira J, Araki N, Bin Othman N, Zakaria Z, Fukuda M, et al.

Biosci Biotechnol Biochem, 2016 May;80(5):1012-9.
PMID: 26828632 DOI: 10.1080/09168451.2015.1127134

Rhodococcus jostii RHA1 (RHA1) degrades polychlorinated biphenyl (PCB) via co-metabolism with biphenyl. To identify the novel open reading frames (ORFs) that contribute to PCB/biphenyl metabolism in RHA1, we compared chromatin immunoprecipitation chip and transcriptomic data. Six novel ORFs involved in PCB/biphenyl metabolism were identified. Gene deletion mutants of these 6 ORFs were made and were tested for their ability to grow on biphenyl. Interestingly, only the ro10225 deletion mutant showed deficient growth on biphenyl. Analysis of Ro10225 protein function showed that growth of the ro10225 deletion mutant on biphenyl was recovered when exogenous recombinant Ro10225 protein was added to the culture medium. Although Ro10225 protein has no putative secretion signal sequence, partially degraded Ro10225 protein was detected in conditioned medium from wild-type RHA1 grown on biphenyl. This Ro10225 fragment appeared to form a complex with another PCB/biphenyl oxidation enzyme. These results indicated that Ro10225 protein is essential for the formation of the PCB/biphenyl dioxygenase complex in RHA1.

Matched MeSH terms: Gene Deletion
[Case of deletion type beta(0)-thalassemia found in an Asian (Malaysian) family living in Japan]

Harano K, Harano T

Rinsho Byori, 2010 Apr;58(4):325-31.
PMID: 20496759

Hb and gene analyses of a Malaysian mother and her two daughters with microcytic anemia living in Japan were performed. Hb analyses of their hemolysates by IEF and DEAE-HPLC revealed high values of Hb A2 and HbF, but abnormal Hbs such as Hb E and Hb Constant Spring, which cause beta- and alpha-thalassemia traits, were not detected. From these data, they were suspected to be beta-thalassemia carriers. The thalassemic mutations commonly found in the Asian area by ARMS and nucleotide sequencing methods were not detected, and the frameworks of the beta-globin gene and the haplotypes of the beta-like globin gene cluster between the mother and daughters were not identical. These results led us to conclude that there was a beta(0)-thalassemia mutation with a large deletion from the beta-globin gene beyond the 3'beta/BamHI polymorphic site 3' downstream to the beta-globin gene. However, the range of the deletion from the beta-like globin gene cluster has not yet been completed in detail. Recently, there have been many foreigners mainly from Asian countries in Japan. We may encounter people with the rare type thalassemic mutation described in the text besides the mutations frequently found in Asian countries.

Matched MeSH terms: Gene Deletion*
Fulltext Peripheral haemolysis, lipid peroxidation, iron status, and vitamin E in haemoglobin H syndromes in West Malaysia

George E, Wong HB, Jamaluddin M, Huisman TH

Singapore Med J, 1993 Jun;34(3):241-4.
PMID: 8266182

Following complete DNA characterisation patients with Hb H disease were assigned into two groups: deletional (alpha +/alpha o) and non deletional (HbCS/alpha o). Earlier studies have indicated that the group with (HbCS/alpha o) has more severe clinical problems. The serum malonyldialdehyde (MDA) levels, a secondary product of lipid peroxidation were within the normal range, though significantly higher levels of MDA were seen in the non-deletional type of Hb H disease when compared with the deletional type. Markedly low vitamin E levels were also seen in the former group. There were no significant differences in clinical severity may be attributed to an interplay of the accelerated destruction of damaged mature red blood cells secondary to the oxidative denaturation of Hb H and inclusion precipitation; higher levels of Hb H and more inclusion precipitation were seen in the group with (HbCS/alpha o). Low levels of vitamin E in the (HbCS/alpha o) group being due to its consumption in the neutralisation of free radicals formed with the oxidation of globin chains.

Matched MeSH terms: Gene Deletion
Fulltext Co-inheritance of compound heterozygous Hb Constant Spring and a single -alpha(3.7) gene deletion with heterozygous deltabeta thalassaemia: a diagnostic challenge

Azma RZ, Othman A, Azman N, Alauddin H, Ithnin A, Yusof N, et al.

Malays J Pathol, 2012 Jun;34(1):57-62.
PMID: 22870600

Haemoglobin Constant Spring (Hb CS) mutation and single gene deletions are common underlying genetic abnormalities for alpha thalassaemias. Co-inheritance of deletional and non-deletional alpha (alpha) thalassaemias may result in various thalassaemia syndromes. Concomitant co-inheritance with beta (beta) and delta (delta) gene abnormalities would result in improved clinical phenotype. We report here a 33-year-old male patient who was admitted with dengue haemorrhagic fever, with a background history of Grave's disease, incidentally noted to have mild hypochromic microcytic red cell indices. Physical examination revealed no thalassaemic features or hepatosplenomegaly. His full blood picture showed hypochromic microcytic red cells with normal haemoglobin (Hb) level. Quantitation of Hb using high performance liquid chromatography (HPLC) and capillary electrophoresis (CE) revealed raised Hb F, normal Hb A2 and Hb A levels. There was also small peak of Hb CS noted in CE. H inclusions was negative. Kleihauer test was positive with heterocellular distribution of Hb F among the red cells. DNA analysis for alpha globin gene mutations showed a single -alpha(-3.7) deletion and Hb CS mutation. These findings were suggestive of compound heterozygosity of Hb CS and a single -alpha(-3.7) deletion with a concomitant heterozygous deltabeta thalassaemia. Co-inheritance of Hb CS and a single -alpha(-3.7) deletion is expected to result at the very least in a clinical phenotype similar to that of two alpha genes deletion. However we demonstrate here a phenotypic modification of alpha thalassemia presumptively as a result of co-inheritance with deltabeta chain abnormality as suggested by the high Hb F level.

Matched MeSH terms: Gene Deletion*
Fulltext Comparative chemical screening and genetic analysis reveal tentoxin as a new virulence factor in Cochliobolus miyabeanus, the causal agent of brown spot disease on rice

De Bruyne L, Van Poucke C, Di Mavungu DJ, Zainudin NA, Vanhaecke L, De Vleesschauwer D, et al.

Mol Plant Pathol, 2016 Aug;17(6):805-17.
PMID: 26456797 DOI: 10.1111/mpp.12329

Brown spot disease, caused by Cochliobolus miyabeanus, is currently considered to be one of the most important yield reducers of rice (Oryza sativa L.). Despite its agricultural importance, little is known about the virulence mechanisms deployed by the fungus. Therefore, we set out to identify novel virulence factors with a role in disease development. This article reports, for the first time, the production of tentoxin by C. miyabeanus as a virulence factor during brown spot disease and the identification of the non-ribosomal protein synthetase (NRPS) CmNps3, responsible for tentoxin biosynthesis. We compared the chemical compounds produced by C. miyabeanus strains differing in virulence ability using ultra-high-performance liquid chromatography (UHPLC) coupled to high-resolution Orbitrap mass spectrometry (HRMS). The production of tentoxin by a highly virulent strain was revealed by principal component analysis of the detected ions and confirmed by UHPLC coupled to tandem-quadrupole mass spectrometry (MS/MS). The corresponding NRPS was identified by in silico genome analysis and confirmed by gene deletion. Infection tests with wild-type and Cmnps3 mutants showed that tentoxin acts as a virulence factor and is correlated with chlorosis development during the second phase of infection. Although rice has previously been classified as a tentoxin-insensitive plant species, our data demonstrate that tentoxin production by C. miyabeanus affects symptom development.

Matched MeSH terms: Gene Deletion
Fulltext Mowat-Wilson syndrome: the first two Malaysian cases

Balasubramaniam S, Keng WT, Ngu LH, Michel LG, Irina G

Singapore Med J, 2010 Mar;51(3):e54-7.
PMID: 20428734

Mowat-Wilson syndrome (MWS) is a recently delineated mental retardation; a multiple congenital anomaly syndrome characterised by a typical facial gestalt, Hirschsprung disease or severe constipation, genitourinary anomaly, congenital heart defects, agenesis of corpus callosum and eye defects. Some cases also present with epilepsy, growth retardation with microcephaly and speech impairment. MWS was first described in 1998 by Mowat et al, and approximately 180 cases have been reported as of August 2008. The syndrome occurs as a result of heterozygous mutations or deletions in the zinc finger E-box-binding homeobox 2 gene, ZEB2, previously called ZFHX1B (SIP1). Most cases reported so far were sporadic occurrences; however, rare cases of sibling recurrence have been cited. The facial phenotype is particularly important for the initial clinical diagnosis and provides the hallmark, warranting ZEB2 mutational analysis even in the absence of Hirschsprung disease. We present the first two molecularly confirmed Malaysian MWS patients, one of whom has a novel mutation.

Matched MeSH terms: Gene Deletion

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