Prevalence of α-thalassaemia genotypes in pregnant women in northern Thailand.

Background & objectives: Alpha-thalassaemias are genetic disorders with high prevalence in northern Thailand. However, common genotypes and current data on the prevalence of α-thalassaemias have not been reported in this region. Therefore, the objective of the present study was to determine the prevalence of α-thalassaemia genotypes in pregnant women in northern Thailand. Methods: Genomic DNA was extracted from blood samples of pregnant women who came to Maharaj Nakorn Chiang Mai University Hospital during July 2009 to 2010. The common deletion and point mutation genotypes of α-thalassaemia were evaluated by gap- polymerase chain reaction (PCR) and PCR with restriction fragment length polymorphism (RFLP). Results: Genotypes of 638 pregnant women were: 409 samples (64.11%) being normal subjects (αα/αα) and 229 samples (35.89%) with α-thalassaemias. These 229 samples could be classified into deletional HbH disease (--SEA/-α3.7) for 18 samples (2.82%); heterozygous α0-thalassaemia --SEA type (--SEA/αα)) for 78 (12.23%); heterozygous α+-thalassaemia - α3.7 type (-α3.7/αα) for 99 (15.52%); homozygous α+-thalassaemia - α3.7 type (-α3.7/- α3.7) for five (0.78%); heterozygous α+-thalassaemia - α4.2 type (-α4.2/αα) for two (0.31%); and heterozygous HbCS (αCSα/αα) for 27 (4.23%) cases. Interpretation & conclusions: The prevalence of α-thalassaemias in pregnant women in northern Thailand was high. This finding supports the implementation of the prevention and control of this common genetic disorder by screening for α-thalassaemia genotypes.

Novel ATRX gene damaging missense mutation c.6740A>C segregates with profound to severe intellectual deficiency without alpha thalassaemia.

Background & objectives: ATRX is a recessive X-linked intellectual deficiency (X-LID) gene causing predominately alpha-thalassaemia with a wide and clinically heterogeneous spectrum of intellectual deficiency syndromes. Although alpha-thalassaemia is commonly present, some patients do not express this sign despite the ATRX gene being altered. Most pathological mutations have been localized in two different major domains, the helicase and the plant homeo-domain (PHD)-like domain. In this study we examined a family of three males having an X-linked mental deficiency and developmental delay, and tried to establish a genetic diagnosis while discussing and comparing the phenotype of our patients to those reported in the literature. Methods: Three related males with intellectual deficiency underwent clinical investigations. We performed a karyotype analysis, CGH-array, linkage study, and X-exome sequencing in the index case to identify the genetic origin of this disorder. The X-inactivation study was carried out in the mother and Sanger sequencing was achieved in all family members to confirm the mutation. Results: A novel ATRX gene missense mutation (p.His2247Pro) was identified in a family of two uncles and their nephew manifesting intellectual deficiency and specific facial features without alpha-thalassaemia. The mutation was confirmed by Sanger sequencing. It segregated with the pathological phenotype. The mother and her two daughters were found to be heterozygous. Interpretation & conclusions: The novel mutation c.6740A>C was identified within the ATRX gene helicase domain and confirmed by Sanger sequencing in the three affected males as well as in the mother and her two daughters. This mutation was predicted to be damaging and deleterious. The novel mutation segregated with the phenotype without alpha-thalassaemia and with non-skewed X chromosome.

Alpha thalassaemia in tribal communities of coastal Maharashtra, India.

Background & objectives: In a routine community health survey conducted in adult Adivasis of the costal Maharashtra, microcytosis and hyprochromia were observed in more than 80 per cent of both males and females having normal haemoglobin levels suggesting the possibility of α-thalassaemia in these communities. We conducted a study in Adivasi students in the same region to find out the magnitude of α-thalessaemia. methods: The participants (28 girls and 23 boys) were 14-17 yr old studying in a tribal school. Fasting venous blood samples (5 ml) were subjected to complete blood count (CBC), Hb-HPLC and DNA analysis using gap-PCR for deletion of – α3.7 and – α4.2, the two most common molecular lesions observed in α-thalassaemia in India. Results: Microcytic hypochromic anaemia was observed 50 and 35 per cent girls and boys, respectively. Iron supplementation improved Hb levels but did not correct microcytois and hypochromia. mMore than 80 per cent non-anaemic students of both sexes showed microcytois and hypochromia. DNA analysis confirmed that the haematological alterations were due to α-thalassaemia trait characterized by deletion of – α3.7. Majority (> 60%) of the affected students had two deletions (-α3.7/-α3.7) genotype α+ thalassaemia. Interpretation & conclusions: This is perhaps the first report on the occurrence of α-thalassaemia in tribal communities of coastal Maharashtra. Very high (78.4%) haplotype frequency of -α3.7 suggests that the condition is almost genetically fixed. These preliminary observations should stimulate well planned large scale epidemiological studies on α-thalassaemia in the region.

Homozygous sickle cell disease in Uganda and Jamaica a comparison of Bantu and Benin haplotypes / La anemia de células falciformes homocigóticas en Uganda y Jamaica comparación de haplotipos Bantú y Benin

OBJECTIVE: To compare the haematological and clinical features of homozygous sickle cell (SS) disease in Bantu and Benin haplotypes in a cross-sectional study of 115 Ugandan patients attending the Sickle Cell Clinic at Mulago Hospital, Kampala, Uganda, with 311 patients in the Jamaican Cohort Study. METHODS: This involved comparison of clinical features and haematology with special reference to genetic determinants of severity including fetal haemoglobin levels, beta-globin haplotype and alpha thalassaemia status. RESULTS: The Bantu haplotype accounted for 94% of HbS chromosomes in Ugandan patients and the Benin haplotype for 76% of HbS chromosomes in Jamaica. Ugandan patients were marginally more likely to have alpha thalassaemia, had similar total haemoglobin and fetal haemoglobin levels but had higher reticulocyte counts and total bilirubin levels consistent with greater haemolysis. Ugandan patients had less leg ulceration and priapism, but the mode of clinical presentation, prevalence of dactylitis, features of bone pain and degree of delay in sexual development, assessed by menarche, were similar in the groups. In Ugandan patients, a history of anaemic episodes was common but these were poorly documented. CONCLUSION: The haematological and clinical features of the Bantu haplotype in Uganda were broadly similar to the Benin haplotype in Jamaica except for less leg ulceration and priapism and possibly greater haemolysis among Ugandan subjects. Anaemic episodes in Uganda were treated empirically by transfusion often without a clear diagnosis; better documentation including reticulocyte counts and observations on spleen size is necessary to evolve appropriate models of care.

OBJETIVO: Comparar los rasgos clínicos de la anemia de células falciformes homocigóticas (SS) en los haplotipos Bantú y Benin en un estudio transversal de 115 pacientes ugandeses que asisten a la Clínica de la anemia de células falciformes en el Hospital de Mulago, Kampala, Uganda, con 311 pacientes en un estudio de cohorte jamaicano. MÉTODOS: El estudio conllevó la comparación de los rasgos clínicos y hematológicos con referencia especial a los determinantes genéticos de la severidad, incluyendo los niveles de la hemoglobina fetal, haplotipos del gen de la globina beta, y el estado de la alfa talasemia. RESULTADOS: El haplotipo Bantú dio cuenta del 94% de los cromosomas HbS en los pacientes ugandeses, en tanto que los haplotipos Benin dieron cuenta del 76% de los cromosomas de HbS en Jamaica. Los pacientes de Uganda presentaron una probabilidad marginalmente mayor de alfa talasemia, tenían niveles similares de hemoglobina total y hemoglobina fetal, pero en cambio presentaban conteos más altos de reticulocitos así como niveles mayores de bilirrubina total, en correspondencia con una mayor hemólisis. Los pacientes ugandeses presentaban menor ulceración de las piernas y priapismo, pero el modo de presentación clínica, la prevalencia de dactilitis, los rasgos de dolor óseo, y el grado de retraso en el desarrollo sexual, evaluado por la menarquia, fueron similares en todos los grupos. Los pacientes de Uganda se caracterizaron comúnmente por una historia de episodios de anemia, pobremente documentados. CONCLUSIÓN: Los rasgos clínicos y hematológicos del haplotipo Bantú en Uganda fueron considerablemente similares al haplotipo Benin en Jamaica, salvo por una menor presencia de ulceración de las piernas y priapismo, así como posiblemente mayor hemólisis entre los sujetos de Uganda. Los episodios de anemia en Uganda fueron tratados empíricamente mediante transfusión, a menudo sin un diagnóstico claro. Se necesita una mejor documentación - incluyendo conteos de reticulocitos - así como observaciones del tamaño del bazo, a fin de desarrollar modelos de cuidado apropiados.

ATR-X syndrome in two siblings with a novel mutation (c.6718C>T mutation in exon 31).

ATR-X syndrome is an X-linked mental retardation syndrome characterized by mental retardation, alpha thalassaemia and distinct facial features which include microcephaly, frontal hair upsweep, epicanthic folds, small triangular nose, midface hypoplasia and carp-shaped mouth. Here we report two brothers with clinical features of ATR-X syndrome, in whom a novel missense (C>T) mutation was identified in exon 31 of the ATRX gene.

Gene type study of alpha-thalassaemia in Chongqing / 重庆医科大学学报

Objectives:To study the distribution status,clinical manifestations and laboratory test characteristics of alpha-thalassaemia gene type in the city of ChongQing to approach the importance of genetic diagnosis for alpha-thalassaemia,and the significance of thia diagnosis for antenatal screening and prenatal diagnosis to promote the survival quality of human being.Methods:This study was performed in the Children's Hospital of Chongqing Medical University.One hundred and three alpha -thalassaemia patients were involved in this study.They had taken the tests of serum iron(SI),total iron binding capacity(TIBC),transferrin saturation(TS),hemoglobin(Hb)electrophoresis and genetic examination.Retrospective study and prospective study were performed with the results.Results:(1)A total of 72 patients underwent SI,TIBC and TS,and 55.56 %(40/72) patients had SI decreased,TIBC increased and TS decreased.(2) 92 serum samples from these patients had Hb electrophoresis,in which 31.52%(29/92) presented fast band.(3) In this study,there were 82.52%(85/103) deletional alpha-thalassaemia and 17.48%(18/103) non-deletional alpha-thalassaemia.(4) In 85 deletional alpha-thalassaemia,alpha0-thalassaemia was more than alpha+-thalassaemia.Conclusion:(1) Deletion form is the main form of ? thalassaemia in ChongQing.(2) alpha0-thalassaemia is less than alpha+-thalassaemia.(3) Genetic diagnosis is the gold standard for this disease.(4) It should be emphasized that antenatal screening and prenatal diagnosis are important for better lives of human beings.(5) Alpha-thalassaemia can affiliate nutritional iron deficiency anemia(NIDA).