Thalassaemia genes in Baghdad, Iraq

To estimate the prevalence of thalassaemia genes in Baghdad, a study was made of 502 randomly selected pregnant women attending a major maternity care clinic in the city. A reduced mean corpuscular volume [MCV] of < 80 fl was used as a screening test for thalassaemia in this population, followed by a battery of tests, including haemoglobin analysis and iron studies, to confirm the diagnosis. Using this approach, 22 cases were diagnosed of beta-thalassaemia trait, five cases of alpha-thalassaemia trait and one case of delta beta-thalassaemia trait. Based on these figures the estimated prevalence rates of beta-, alpha- and delta beta-thalassaemia traits in Baghdad, would be 4.4%, 1.0% and 0.2%, respectively. The study also includes a discussion of the above findings in the context of those reported in other neighbouring countries

P–539 The use of expanded carrier screening of gamete donors

Study question What are the sperm and egg donor rejection rates after expanded carrier screening (ECS)? Summary answer Using an ECS panel looking at 46/47 genes, 17.6% of donors were rejected. What is known already The use of ECS is becoming commonplace in assisted reproductive technology, including testing of egg and sperm donors. Most national guidelines recommend rejection of donors if they are carriers of a genetic disease. If the use of ECS increases, there will be a decline in the number of donors available. Study design, size, duration A review of the current preconception ECS panels available to donors was carried out through an online search. The genetic testing results of donors from Cryos International were analysed to determine how many were rejected on the basis of the ECS. Participants/materials, setting, methods Data on gamete donors and their carrier status was provided by Cryos International, who screen donors using their own bespoke ECS panel. The ECS panels identified through the review were compared to the Cryos International panel and data. Main results and the role of chance A total of 16 companies and 42 associated ECS panels were reviewed. There were a total of 2673 unique disorders covered by the panels examined, with a mean of 329 disorders screened. None of these disorders were common to all panels. Cryos International screen 46 disorders in males and 47 in females. From 883 candidate donors, 17.6% (155/883) were rejected based on their ECS result. Carriers of alpha-thalassaemia represented the largest proportion of those rejected (19.4%, 30/155), then spinal muscular atrophy (15.5%, 24/155) and cystic fibrosis (14.8%, 23/155). Limitations, reasons for caution Panel information was found on company web sites and may not have been accurate. Wider implications of the findings: This study highlights the need for consistent EU regulations and guidelines which allow genetic matching of gamete donors to recipients, preventing the need to reject donors who are known carriers. A larger ECS panel would be most beneficial, however, this would not be viable without matching of donors and recipients. Trial registration number Not applicable

Screening for thalassaemia among group of students of a higher institution – our experience

Introduction: Thalassaemia is an inherited blood disorder and is a significant public health alarm in Malaysia with many not knowing they are carriers of this haemoglobin disorders. Materials and methods: This study conducted a one off collection of blood samples from 72 Malays students of International Islamic University Malaysia (IIUM) in Kuantan. Blood samples were subjected to conventional haemoglobin analyses that include full blood count and picture, HPLC, Haemoglobin electrophoresis and H-inclusion test. All samples were also genotyped for alpha thalassaemia–1 of Southeast Asia (a-Thal1SEA). Result: There were 17(23.6%) students who were diagnosed as thalassaemia carriers. Out of this, four (5.5 %) and six (8.3 %) students were presumptive β-thalassaemia trait and Haemoglobin-E trait as determined by the HPLC assay respectively. Nine (12.5%) students were genotyped a-Thal1SEA among whom two were also β-thalassaemia carriers. All thalassaemia cases had MCH of < 27pg. Nonetheless, two out of six Haemoglobin-E trait and three out of nine a-Thal1SEA carrier had MCV value of >80fL. Two out of four (50%) presumptive β -thalassaemia trait and one out of six (17%) students of presumptive Haemoglobin-E trait had family history of thalassaemia respectively. Conclusion: The high occurrence of the three common types of thalassaemia carrier (β, Hb-E and a-Thal1SEA thalassaemia) in our small group of subjects could be due to better participation of students who had family history of thalassaemia. The study reaffirmed the importance of molecular study for detection of alpha-thalassaemia and the use of MCH value of <27pg rather than MCV value of < 80fL for prediction of thalassaemia.

Interaction of Hematological Analysis and α-globin Genotypes among Eligible Blood Donors

Introduction: Alpha thalassaemia is one of the haemoglobin disorders in which the carriers of alpha thalassaemia may have normal haemoglobin level and are eligible to donate blood which may bring complications. This study is to investigate the interaction of haematological parameter with α-globin genotypes among eligible blood donors. Materials & Methods: A cohort study with 270 eligible blood donors were analysed for red cell indices. Alpha-globin (α-globin) genotyping was performed for seven deletions, six point mutations and two triplications. Statistical analyses were performed to compare the α-globin genotypes with haematological data. Results: High prevalence of α-thalassaemia carriers (7.7%, 21/270) was found among blood donors. All of them did not show anaemic pictures with a normal Hb level (>12 gm/dl). Five genotypes were identified consisting of 249 αα/αα (92.2%), nine -α 3.7/αα (3.3%), nine-- SEA/αα (3.3%), two -α 4.2/αα (0.7%) and one ααCS/αα (0.4%). Different α-globin genotypes showed a significant difference in RBC, MCV, MCH, MCHC, RDW, and Hct/Hb ratio (p<0.05) due to the different extent of α-globin chain reduction. Conclusion: Our study concluded that by using Hb level alone is not sufficient to screen for the eligibility of blood donors. Full blood count (FBC) screening with borderline MCV and MCH levels might be able to rule out silent α-thalassemia carriers. FBC and molecular characterisation should be incorporated together to properly rule out α-thalassaemia carriers.><0.05) due to the different extent of α-globin chain reduction. Conclusion: Our study concluded that by using Hb level alone is not sufficient to screen for the eligibility of blood donors. Full blood count (FBC) screening with borderline MCV and MCH levels might be able to rule out silent α-thalassemia carriers. FBC and molecular characterisation should be incorporated together to properly rule out α-thalassaemia carriers.

A Case of Parvovirus-Related Haemophagocytic Lymphohistiocytosis in a Patient with HbH Disease

Hemophagocytic lymphohistiocytosis (HLH) is rare and life-threatening medical emergency. Parvovirus infection is rarely associated with HLH. We report a case of parvovirus-related HLH in a patient with alpha thalassaemia (HbH disease). The patient responded well to a course of dexamethasone without the need of etoposide. Based on our literature search, this is the first case of parvovirus related HLH in a patient with HbH disease in the medical literature.

Prenatal diagnosis and management of fetal discordant alpha-thalassaemia in dichorionic diamniotic (DCDA) twins

A 29-year-old nulliparous woman with a dichorionic diamniotic (DCDA) twin pregnancy was referred to our hospital at 16 weeks’ gestation for prenatal diagnosis. She was diagnosed of Haemoglobin H Constant Spring (Hb H CS; --SEA/αCSα) and her husband of alpha thalassemia-1 trait (--SEA/αα). Detailed ultrasound showed that left twin had fetal anaemia and early signs of hydrops while the right one was normal. Both twins were female. Amniocentesis in each sac was performed for prenatal diagnosis of thalassemia after a proper counselling with the couple. DNA analysis confirmed that the left fetus was affected with haemoglobin Bart’s hydrops fetalis (--SEA/--SEA) while the right one was alpha thalassemia-1 trait (--SEA/αα). Selective feticide with intracardiac injection of KCl was successfully performed on the hydropic fetus. Identification of the affected fetus is crucial for selective termination. Family counselling about the procedure and complications is also necessary.