The hyper-methemoglobinemia causes the oxygen transfer disorder. The clinical symptoms depends on the level of methemoylobinemia. Hypermethemoglobinemia can be congenital or acquired hypermethemoglobinemia. The congenital hypermethemoglobinemia caused by partial or total methemoglobine reeducates deficiency in patients with rare genetic heterozygous enzyme deficiency due to the abnormal hemoglobin. The acquired hypermethemoglobinemia occurred after exposure to colour compound, food and drinking water with nitrate or drugs. The determination of causative agent of hypermethemoglobin help treating more effectively
Methemoglobin ; Hemoglobins, Abnormal ; Therapeutics ; Methemoglobinemia

Humans ; Hemoglobinopathies ; Hemoglobins, Abnormal/genetics*

Hemoglobins, Abnormal ; Humans ; Singapore/epidemiology* ; alpha-Thalassemia

Humans ; Hemoglobinopathies ; Hemoglobins, Abnormal/genetics* ; Oxygen

OBJECTIVETo analyze genotypic profiles and understand the relationship between the genotype and phenotype of Hb H disease in Guangxi province.

METHODSHematologic and Hb analyses on the cases were performed to detect their alpha thalassemia genotypes using PCR method and DNA sequencing.

RESULTSAn unusual case was identified in one of the 298 patients with Hb H disease diagnosed in the First Affiliated Hospital of Guangxi Medical University from October 2002 to November 2003. The 25-year-old male patient, a native of Yulin in Guangxi province, had had jaundice and splenomegaly since childhood, and he had never received blood transfusion. Hematologic examinations revealed his hemoglobin 107 g/L, RBC 4.9+10(12) g/L, MCV 76.2 fl, MCH 21.8 pg, MCHC 287 g/L, HCT 0.373, reticulocyte 3%. Hb analysis showed the level of Hb H + Hb Bart's 34.41%. PCR and DNA sequencing confirmed the genotype of a deletion at codon 30 of alpha2 globin gene and SEA alpha-thalassemia-1.

CONCLUSIONThis unusual case had no anemia, but had higher level of Hb H and Hb Bart's when compared to those non-deletional Hb H disease cases such as Hb CS-H, HbQS-H and alpha2 codon 31 mutation combined with SEA alpha-thalassemia-1 previously reported in mainland China. The discovery and recognition of this gene mutation and related genotype and phenotype is of importance to the genetic counseling and prenatal diagnosis in Guangxi province where the incidence of alphathalassemia is very high.

Adult ; China ; DNA Mutational Analysis ; Genotype ; Hemoglobin H ; genetics ; Hemoglobins, Abnormal ; genetics ; Humans ; Male ; Phenotype ; Polymerase Chain Reaction ; alpha-Thalassemia ; genetics

There is a high prevalence of thalassemia in the South of China. To explore the genotype of alpha-thalassemia as well as the distribution of alpha globin gene mutation in the South of China, 356 patients with heterozygote alpha(+) thalassemia, heterozygote alpha(0) or homozygote alpha(+) thalassemia and 78 patients with HbH were analyzed. The gene diagnosis methods including Gap-PCR, nested-PCR, PCR-RE, PCR-SSCP, 4P-ASPCR and DNA sequence analysis were used. The results showed that among 356 patients, 295 patients with --SEA/alphaalpha (82.87%), 1 patient with alphaalpha/alpha-alpha(3.7) (0.28%), 3 patients with alphaalpha/alpha-alpha(4.2) (0.84%), 3 patients with alphaalpha/alpha(CS)alpha (0.84%), 1 patient with alphaalpha/alphaalpha(QS) (0.28%) and 2 patients with alphaalpha/alpha(Westmead) alpha (0.56%) were found. The homozygote with -alpha(4.2) or -alpha(3.7) was not found. In 78 patients with HbH, 29 patients with --SEA/alphaalpha(-3.7) (37.2%), 20 patients with --SEA/alphaalpha(-4.2) (25.6%), 19 patients with --SEA/alphaalpha(CS) (24.3%), 2 patients with --SEA/alphaalpha(QS) (2.6%) were detected, and other remaiming 8 patients were needed to be defined. Among the non-defined 8 patients, the synonymous mutation with C-->G transversion (GCC-GCG) at codon 65 in the exon 2 of alpha 2-globin gene was detected in 2 unrelated HbH patients came from Guangxi province. Whether it correlated with the phenotype of HbH disease or it is only a single nucleotide polymorphism site (SNPs), should be confirmed in the future. In addition, a set of gene diagnosis methods based on PCR to screen deletion and non-deletion genotypes of alpha-thalassemia in Chinese was improved. A new method, 4P-ASPCR, to detect Hb CS and Hb QS was also developed. The method was verified to be more accurate, time-saving and economic. In conclusion, the genotypes of alpha-thalassemia in Chinese are very complicated, the genotypes of alpha-thalassemia in Chinese need to be further studied, the results of this research probably have practical significance for the gene diagnosis or antenatal diagnosis of alpha-thalassemia in the South of China.
Base Sequence ; China ; DNA ; chemistry ; genetics ; DNA Mutational Analysis ; Gene Deletion ; Gene Frequency ; Genotype ; Globins ; genetics ; Hemoglobin H ; genetics ; Hemoglobins ; genetics ; Hemoglobins, Abnormal ; genetics ; Humans ; Molecular Sequence Data ; Mutation ; Polymorphism, Single-Stranded Conformational ; alpha-Thalassemia ; genetics ; pathology

Aged ; Anemia, Sickle Cell ; complications ; pathology ; Arthritis, Rheumatoid ; complications ; Female ; Hemoglobin E ; Hemoglobin, Sickle ; Humans

Cyanosis in children is most often caused by pulmonary disease, or cyanotic heart disease but is rarely caused by hematological problems such as methemoglobinemia and sulfhemoglobinemia. Abnormal hemoglobins with a reduced oxygen affinity are an exceptionally uncommon cause of cyanosis in children. Hemoglobin-M (Hb-M) is rapidly auto-oxidized into the met-form resulting in the loss of its O2-binding ability. This hemoglobinopathy is inherited in an autosomal dominant pattern and is characterized by marked cyanosis. Hb-M affects the anesthetic management because of the anomalous absorption spectrum of Hb-M in standard pulse oximetry. Sufficient O2 delivery should be maintained by keeping a high FiO2 and intermittently checking the O2 delivery state using arterial blood gas analysis. We reported our experience of the anesthetic management of a patient with hemoglobin M.
Absorption ; Blood Gas Analysis ; Child ; Cyanosis ; Heart Diseases ; Hemoglobin M ; Hemoglobinopathies ; Hemoglobins, Abnormal ; Humans ; Lung Diseases ; Methemoglobin ; Methemoglobinemia ; Oximetry ; Oxygen ; Sulfhemoglobinemia

Genome editing tools such as the clustered regularly interspaced short palindromic repeat (CRISPR)-associated system (Cas) have been widely used to modify genes in model systems including animal zygotes and human cells, and hold tremendous promise for both basic research and clinical applications. To date, a serious knowledge gap remains in our understanding of DNA repair mechanisms in human early embryos, and in the efficiency and potential off-target effects of using technologies such as CRISPR/Cas9 in human pre-implantation embryos. In this report, we used tripronuclear (3PN) zygotes to further investigate CRISPR/Cas9-mediated gene editing in human cells. We found that CRISPR/Cas9 could effectively cleave the endogenous β-globin gene (HBB). However, the efficiency of homologous recombination directed repair (HDR) of HBB was low and the edited embryos were mosaic. Off-target cleavage was also apparent in these 3PN zygotes as revealed by the T7E1 assay and whole-exome sequencing. Furthermore, the endogenous delta-globin gene (HBD), which is homologous to HBB, competed with exogenous donor oligos to act as the repair template, leading to untoward mutations. Our data also indicated that repair of the HBB locus in these embryos occurred preferentially through the non-crossover HDR pathway. Taken together, our work highlights the pressing need to further improve the fidelity and specificity of the CRISPR/Cas9 platform, a prerequisite for any clinical applications of CRSIPR/Cas9-mediated editing.
Blastocyst ; CRISPR-Cas Systems ; Hemoglobins, Abnormal ; genetics ; metabolism ; Humans ; Zygote

Hemoglobins, Abnormal ; Humans ; alpha-Thalassemia ; complications ; beta-Thalassemia ; complications