Purpose: Given the potential role of light and its wavelength on ocular growth, this study investigated the effect of short-term exposure to red, cyan and blue light on ocular biometry in humans.
Methods: Forty-four young adults and 20 children, comprising emmetropes and myopes, underwent 2-h sessions of cyan (507 nm), red (638 nm) and broadband white light on three separate days via light-emitting glasses. Additionally, young adults were exposed to blue light (454 nm) on an additional day.
Purpose: Previous studies have shown that time spent outdoors is protective against myopia development in children. In this study, we examined the effects of 500 and 1000 lux of illumination to the eye on axial length (AL) and choroidal thickness (CT) changes in young adults.
Methods: Fifteen participants (mean age, 21.
Sickle cell disease is a genetic disorder with a large variability in the pattern and severity of clinical manifestations. Different genetic modulators have been identified but very few epidemiologic data are available on these modifier genes in Senegal. This study aimed to determine their prevalence in a Senegalese sickle cell disease pediatric population.
View Article and Find Full Text PDFObjectives: Because of the increased hemolytic rate, a significant proportion of patients with sickle cell disease (SCD) are prone to develop cholelithiasis. The present study investigated the role of several genetic factors (UGT1A1 promoter (TA) repeat polymorphism, alpha-globin status), hematological parameters, clinical severity, and hydroxyurea (HU) therapy on the occurrence of cholelithiasis in SCD.
Methods: One hundred and fifty-eight children (2-18 yr old) regularly followed at the University Hospital of Lyon (France) were included.
We have identified a deletion of 125 bp (α-α(Δ125)) (NG_000006.1: g.37040_37164del) in the α-globin gene cluster in a Kabyle population.
View Article and Find Full Text PDFIntroduction: The alpha-1 antitrypsin (α1-AT) deficiency, most frequently caused by homozygosity for the Z variant (SERPINA1: c.1096 G>A; Glu342Lys), can give rise to two clinical patterns: (i) respiratory impairment with emphysema (mainly in adulthood) because of a pulmonary quantitative defect in anti-elastase activity; (ii) hepatic impairment (mainly in childhood) due to the misfolding of the PiZ protein which accumulates in hepatocytes thus providing cytotoxicity.
Current Knowledge: To date, the clinical and genetic factors responsible for the development of major hepatic injuries (fibrosis and portal hypertension) during childhood in PiZ patients are not known.
We present here seven new hemoglobin (Hb) variants identified during routine Hb analysis. All of them are caused by a missense mutation except Hb Saint Chamond, which results from an in-frame deletion of the asparagine residue at β80. All these variants are clinically silent in the heterozygous state but two of them (Hb Cap d'Agde and Hb Dompierre) may be unstable, whereas Hb Nîmes could present a very slightly elevated oxygen affinity.
View Article and Find Full Text PDFWe report a new β-globin chain variant: Hb Meylan [β73(E17)Asp → Phe; HBB: c.220G>T; c.221A>T].
View Article and Find Full Text PDFWe here report the phenotypes and genotypes of 63 patients of North African origin, carriers of Hb Groene Hart [Hb GH, α119(H2)Pro → Ser; HBA1: c.358C>T], an α(+)-thalassemia (α(+)-thal) hemoglobin (Hb) variant. Fifty patients were heterozygous, five were homozygous and eight also carried the common -α(3.
View Article and Find Full Text PDFBackground: Minucci et al. have proposed in 2010 a rapid, simple and cost-effective HRM method on the LightCycler 480® apparatus (Roche) for the determination of the 6/6, 6/7 and 7/7 genotypes of the (TA)n UGT1A1 promoter polymorphism. However, they have not studied the n=5 and n=8 alleles which can be quite frequent in sickle-cell disease patients.
View Article and Find Full Text PDFWe present two case reports in which an HBD mutation is present with a rare α hemoglobinopathy that substantially complicates the associated phenotype. In the first case, a new δ-globin variant, Hb A2-Pierre-Bénite [δ83(EF7)Gly→Arg; HBD: c.250G>C] is associated with Hb Groene Hart [α119(H2)Pro→Ser (α1); HBA1: c.
View Article and Find Full Text PDFWe report two new variants of the δ-globin gene: Hb A(2)-Saint-Etienne [δ14(A11)Leu→Pro] and Hb A(2)-Marseille [δ22(B4)Ala→Lys]. The first variant has a low rate of expression, the second results from a double nucleotide mutation on the same codon.
View Article and Find Full Text PDFBackground: Deletions represent about 5% of the mutations in the β-globin gene cluster. We report here the screening for such deletions in the two French urban areas of Paris and Lyon between 2003 and 2010.
Methods: Semi-quantitative PCR methods were used for the first screening of deletions.
J Chromatogr B Analyt Technol Biomed Life Sci
February 2012
DNA analysis is currently the easiest way to identify a hemoglobin variant in most cases. Nevertheless, in case of complex gene rearrangements, mass spectrometry studies may be required to orientate the DNA diagnosis. The present report shows the use of mass spectrometry techniques prior to DNA analysis for the identification of the rare P-Nilotic fusion hemoglobin.
View Article and Find Full Text PDFThe diagnosis of deficiency of alpha-1 antitrypsin (A1AT) is based on isoelectric focusing of serum proteins and the extent of serum. However, the focusing is technically difficult and a greatly reduced concentration in abnormal A1AT tapeless does not differentiate an unstable variant of a variant called 'null' (that is to say without any phenotypic expression) to 'heterozygous' state. In this study, we compared the results of the assay, the phenotype and genotype of A1AT in 50 patients.
View Article and Find Full Text PDFDeletions in the β-globin locus control region (β-LCR) lead to (εγδβ)(0)-thalassemia [(εγδβ)(0)-thal]. In patients suffering from these rare deletions, a normal hemoglobin (Hb), phenotype is found, contrasting with a hematological thalassemic phenotype. Multiplex-ligation probe amplification (MLPA) is an efficient tool to detect β-LCR deletions combined with long-range polymerase chain reaction (PCR) and DNA sequencing to pinpoint deletion breakpoints.
View Article and Find Full Text PDFBackground: β-Globin haplotypes are important to predict the clinical development of patients suffering from sickle cell disease (SCD). Five main haplotypes (Benin, Bantu, Senegal, Cameroon and Arabic-Indian) are defined for β(S) chromosomes and their determination usually requires the genotyping by restriction fragment length polymorphism (RFLP) of six to eight single nucleotide polymorphisms (SNPs). However, RFLP is time-consuming and can lead to a misdiagnosis in case of a supplementary SNP on the restriction sequence.
View Article and Find Full Text PDFWe report two new hemoglobin (Hb) variants; one causing an impairment of the N-terminal glycation of the β-globin chain and the other a hematological phenotype of α-thalassemia (α-thal). The first variant is Hb Aix-les-Bains [β5(A2)Pro→Leu] and the second Hb Dubai [α122(H5)His→Leu (α2)]. These two new Hb variants were detected by chromatographic and electrophoretic methods and characterized by molecular studies.
View Article and Find Full Text PDFObjectives: The Mediterranean and A(-) G6PD variants are particularly prevalent in Africa and Southern Europe. Our study was aimed to develop an assay for the rapid genotyping of these two variants by HRM.
Methods: After PCR reactions corresponding to the G6PD Mediterranean (exon 6), G6PD (A-) (exon 4) and G6PD (A-) (exon 5) mutations, amplicons were submitted to HRM.
We present here five new hemoglobin (Hb) variants which have been identified during routine Hb analysis before their genotypic characterization. Four of these result from a classical missense mutation: Hb Canuts [alpha85(F6)Asp-->His (alpha1)], Hb Ambroise Pare [alpha117(GH5)Phe-->Ile (alpha2)], Hb Beaujolais [beta84(EF8)Thr-->Asn] and HbA(2)-North Africa [delta59(E3)Lys-->Met]. The last one, Hb Monplaisir [beta147 (Tyr-Lys-Leu-Ala-Phe-Phe-Leu-Leu-Ser-Asn-Phe-Tyr-158-COOH)], results from a frameshift mutation at the stop codon of the beta-globin gene which leads to a modified C-terminal sequence in the beta-globin chain.
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