Association Analysis between Genotype and Phenotype of α,β-Thalassaemia Carriers in Huizhou Area of Guangdong Province / 中国实验血液学杂志

OBJECTIVE@#To analyze the prevalence, genotype distribution and hematological characteristics of α,β-thalassaemia carriers in Huizhou area of Guangdong Province.@*METHODS@#10 809 carriers of simple β-thalassaemia and 1 757 carriers of α,β-thalassaemia were enrolled as our study cohort. The hematological parameters were detected by automated blood cell counters and automatic capillary electrophoresis. Suspension array technology, gap-polymerase chain reaction (gap-PCR) and PCR-reverse dot blot were used for the genotyping of thalassaemia carriers.@*RESULTS@#The prevalence of α,β-thalassaemia in Huizhou area of Guangdong Province was 1.99%. A total of 62 genotypes were detected, and the most prevalent genotype was --SEA/ αα, βCD41-42/ βN (19.29%), the next was --SEA/ αα, βIVS-II-654/ βN (16.73%). Significant differences in mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were found between different genotype groups for simple β-thalassaemia and α,β-thalassaemia. Violin plots showed that carriers with co-inheritance of β-thalassaemia and mild α-thalassaemia expressed the lightest anemia, and carriers with co-inheritance of β-thalassaemia and hemoglobin H (Hb H) disease expressed the most severe anemia.@*CONCLUSION@#There is a high prevalence of α,β-thalassaemia in Huizhou area of Guangdong Province. Because of the lack of specific hematological makers for diagnosis of α,β-thalassaemia, it is necessary to distinguish it from simple β-thalassaemia by genotyping of α- and β-thalassaemia in order to correctly guide genetic counseling and prenatal disgnosis.

Analysis of hematological characteristics of patient with different genotypes in lightβ-thalassemia / 实用医学杂志

Objective To investigate the hematological characteristics of patients with light β- thalassae-mia and rapidly identify different mutational genotypes. Methods RBC、Hb、MCV、MCH、MCHC、RDW-CV and HbA2 were studied in the 646 patients,the differences between β0/βN and β +/βN mutations were also compared. Results Most of them were microcytic hypochromic anemia. The most common genotype were β654/βN(33%)、β41-42/βN(32.5%)、β17/βN(14.4%)、β - 28/βN(10%)respectively,β0/βN were relatively higher. The differences in RBC、MCV、MCH、RDW-CV and HbA2 were significant between β0/βN and β +/βN. Compared with β +/βN patients,the MCV and MCH of β0/βN were significantly reduced,RDW-CV and HbA2 were significantly higher. Conclusion Light β- thalassaemia with different genotypes has its own unique hematological features and can be quickly and ef-fectively identified. Clinical efficiency can be improved through hematological analysis.

Association of BCL11A genetic variant (rs11886868) with severity in β-thalassaemia major & sickle cell anaemia.

Background & objectives: The amount of foetal haemoglobin that persists in adulthood affects the clinical severity of haemoglobinopathies including β-thalassaemia major and sickle cell anaemia (SCA). The present study was undertaken to analyse β-thalassaemia as well as SCA patients for the single nucleotide polymorphism (SNP), rs11886868 (T/C) in BCL11A gene and to evaluate the association between this polymorphism and severity of β-thalassaemia major and SCA. Methods: A total of 620 samples (420 β-thalassaemia major and 200 SCA cases) were analysed before blood transfusion using basic screening tests like complete blood analysis and osmotic fragility and further confirmed by high performance liquid chromatography (HPLC), amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) and reverse dot blot techniques. All patients were transfusion dependent. Patients with β-thalassaemia and SCA were classified into mild, moderate, severe according to the severity score based on Hb levels, age of onset, age at which patients received their first blood transfusion, the degree of growth retardation and splenectomy. β-thalassaemia as well as SCA patients were analysed for the SNP, rs11886868 (T/C) in BCL11A gene and association between this polymorphism and severity of β-thalassaemia major as well as SCA was evaluated. Results: There was a significant difference in genotypic and allelic frequencies of BCL11A gene polymorphism between mild and moderate and mild and severe cases in both the groups. A significant (P<0.001) difference was observed in the mean HbF levels between the three genotypes in different severity groups. HbF levels were found to be high in CC genotype bearing individuals followed by TC and TT in β-thalassaemia major as well as SCA. Interpretation & conclusions: This study confirms that the T/C variant (rs11886868) of the BCL11A gene causing downregulation of BCL11A gene expression in adult erythroid precursors results in the induction of HbF and ameliorates the severity of β-thalassaemia as well as SCA.

Evaluation of carotid artery dynamics & correlation with cardiac & hepatic iron in β-thalassaemia patients.

Background & objectives: Early atherosclerosis and vascular complication have been described in thalassaemia patients. There is lack of data or guidelines regarding monitoring of vascular health in thalassaemia. This study was conducted to compare carotid artery structural and functional indices such as carotid artery intima-media thickness (CIMT), stiffness index (SI) and Young’s elastic modulus (YEM) in β-thalassemia patients with age and sex matched controls, and to correlate these parameters with serum ferritin, cardiac iron, and hepatic iron. Methods: This cross-sectional study included 53 β-thalassaemia patients receiving regular blood transfusions. Carotid artery indices such as CIMT, SI, and YEM were calculated by duplex ultrasound and colour Doppler. Serum ferritin levels were measured by chemiluminescence. Cardiac and hepatic iron estimation were done using MRI T2* sequences analyzed by a special thalassaemia software. Results: Mean CIMT of cases and controls were 0.48 ± 0.04 and 0.44±0.02 mm, respectively and these were significantly different (P<0.001). Similarly significant differences were noted in SI and YEM of cases (2.45±0.79 and 96.12±34.85, respectively) as compared to controls (1.98±0.54 and 68.60±24.29, respectively) (P<0.001). There was significant inverse correlation between stiffness index and cardiac iron overload assessed by MRI cardiac T2* (P=0.03). Mean SI and YEM of cases were (2.1736 ± 0.2986 and 107.3± 41.6, respectively) significantly higher among non-splenectomized patients compared to splenectomized patients (2.0136 ± 0.263 and 86.9 ± 25.2, respectively) (P<0.05). Interpretation & conclusions: CIMT and arterial stiffness indices were significantly increased in β-thalassaemia patients compared to controls which was indicative of early atherogenic changes. This study supports the hypothesis that iron overload is a risk factor for early atherosclerosis and cardiovascular disease.

Haemoglobinopathies in tribal populations of India.

Haemoglobinopathies particularly haemoglobin S and E (HbS, HbE) and β-thalassaemia are important challenges for tribal populations in India. The HbS, HbE and β-thalassaemia genes are variably distributed across various tribal populations of India. HbE is mainly restricted in tribals of North-East, West Bengal, Odisha and those in Andaman and Nicobar islands. HbS has more extensive distribution in the country (10-40% trait frequency) and the homozygotes and double heterozygotes present with a wide array of morbidities. the morbidity varies greatly in different areas of the country due to differential co-inheritance of α-thalassaemia gene and interaction of various epistatic and environmental factors. Though substantial data on prevalence of these disorders exist, there is an urgent need to develop integrated hierarchical core facilities to manage the disease. Such centres will generate more data and will also explore areas of management which need more local attention. Newborn screening, genetic counselling, carrier detection, prenatal diagnosis along with management of cases should form the basic infrastructure of haemoglobinopathy management. Research in this areas should continue focusing on various challenges in care delivery, prevention and basic sciences on interaction of haemoglobinopathies with various other infections.

Hb Lepore/β0-Thalassaemia With α+-Thalassaemia Interactions, A Potential Diagnostic Pitfall

Haemoglobin (Hb) Lepore is a variant Hb consisting of two α-globin and two δβ-globin chains. In a heterozygote, it is associated with clinical findings of thalassaemia minor, but interactions with other haemoglobinopathies can lead to various clinical phenotypes and pose diagnostic challenges. We reported a pair of siblings from a Malay family, who presented with pallor and hepatosplenomegaly at the ages of 21 months and 14 months old. The red cell indices and peripheral blood smears of both patients showed features of thalassaemia intermedia. Other laboratory investigations of the patients showed conflicting results. However, laboratory investigation results of the parents had led to a presumptive diagnosis of compound heterozygote Hb Lepore/β-thalassaemia and co-inheritance α+-thalassaemia (-α3.7). Hb Lepore has rarely been detected in Southeast Asian countries, particularly in Malaysia. These two cases highlight the importance of family studies for accurate diagnosis, hence appropriate clinical management and genetic counseling.

Serum Fasting Lipid Profile In Children And Adolescents With -Thalassaemia Major In Southern Pakistan

Objective: Serum fasting lipid profile has been studied in various clinical spectrum of Beta (β)- thalassaemia syndrome. Premature cardiac impairment in thalassaemia major appears primarily due to iron accumulation and oxidative injury; however it might be a sequel of abnormal lipoprotein concentrations. The rational of this study is to analyse the serum fasting lipid profile in cardiovascular disease free β-thalassaemia major (β-TM) patients. Relationships with age, gender, haematological parameters, liver enzymes and serum ferritin were observed. Method: Fasting serum lipid levels, liver function test (LFT), complete blood count (CBC) and serum ferritin were measured in 36 patients with homozygous β-TM from March 2012 to March 2014. Patients were stratified into two groups, age ≤15 and >15 years, to determine the possible lipid profile distinction in relation to age. Results: 17 were males and 19 were females, with median age of 12.0 years. The mean total cholesterol (TC) and triglyceride (TG) were 5.01±1.32 and 8.36±5.28 mmol/L respectively. High TG was detected in 36.1%, while high density lipoprotein cholesterol (HDL) and low density lipoprotein cholesterol (LDL) were markedly low, 0.98±0.51 and 2.35±1.22 mmol/L respectively. No statistically significant difference was noted between the two age groups. The median TC to HDL ratio (TC:HDL) was elevated, 5.7 (4.0). We established significant correlation of total bilirubin with TC (r=-0.4), HDL(r=-0.5) and LDL (r=-0.4) (P<0.05). Conclusion: Dyslipidaemia in β-TM patients is irrespective of age and gender including low HDL and high TC:HDL, whilst high TC:HDL may contribute as a significant risk marker for future cardiac events in these patients.

Endocrine abnormalities in children with Beta thalassaemia major.

Background: Endocrine complications in β-thalassaemia major patients in developing countries are likely to occur at younger ages due to suboptimal iron chelation. Objective: To assess the prevalence of endocrine abnormalities and correlate serum ferritin, degree of anaemia and liver dysfunction with endocrine dysfunction Method: A cross sectional study was carried out in B. J. Wadia Hospital, over a period of 2 years, on all children with β-thalassemia major over the age of 4 years receiving regular blood transfusions. Patients with transfusion dependent anaemia other than β-thalassemia major were excluded. Results: The total number of children over 4 years of age with β-thalassaemia major receiving regular blood transfusions during the study period was 135. Mean haemoglobin was 7.8 ± 0.6g/dl and the mean serum ferritin level 5295 ± 2736ng/ml. The most common endocrine abnormality was delayed puberty (68%). Seventy one (52.5%) patients had short stature with the height Z-score 2.8±0.8. Hypocalcaemia was observed in 40 (38%) patients. Ten (9.4%) patients had hypoparathyroidism while in 7 (6.6%) it was suspected based on hypocalcaemia, high phosphorus and normal alkaline phosphatase. Rickets was seen in 25 (23.5%) patients. Hypothyroidism was present in 22 (22%) patients of whom 14 had compensated hypothyroidism. Insulin resistance, impaired fasting glucose/impaired glucose tolerance (IFG/IGT) and diabetes mellitus were seen in 7.6%, 4.4% and 2.6% patients respectively. Mean age of patients with delayed puberty was 15.8±1, short stature 10.3±3.4, hypoparathyroidism 10.4±4.2, hypothyroidism 10.4±3, IFG/IGT 10.4±2 and diabetes mellitus 14.2±1.2 years. Bone mineral density was done in 48 patients older than 10 years. Eighteen (37.5%) patients had spinal osteoporosis. Five patients had more than one endocrine abnormality. Conclusions: There were no statistically significant differences between the patients with and without endocrine abnormalities with respect to serum ferritin, mean pre-transfusion haemoglobin and liver dysfunction except for ferritin in patients with hypoparathyroidism and diabetes mellitus.

Serum Soluble Transferrin Receptor Concentration as a Biomarker of Erythropoietic Activity: Surrogate Marker of Adequate Transfusion in Adult Beta-Thalassaemia Intermedia Patients

Management of Beta (β)-thalassaemia intermedia in contrast to β-thalassaemia major patients has no clear guidelines as to indicators of adequate transfusion. Regular blood transfusion suppresses bone marrow erythropoietic activity. Serum soluble transferrin receptor (sTfR) concentration is a marker for erythropoietic activity, with increased sTfR being associated with functional iron defi ciency and increased erythropoietic activity. This study aimed to determine the use of sTfR as an indicator of adequate transfusion in adult β-thalassaemia intermedia patients. A cross-sectional study was conducted at Hospital Ampang, Malaysia, for six months. Patient group included six β-thalassaemia intermedia and 34 HbE-β-thalassaemia transfused patients. None of the patients were on regular monthly blood transfusions as in β-thalassaemia major. The control group comprised of 16 healthy subjects with normal haematological parameters. Haemoglobin (Hb) analysis, sTfR and ferritin assays were performed. Hb and HbA percentages (%) were found to be signifi cantly lower in patients compared to the controls, while HbE%, HbF%, sTfR and ferritin were signifi cantly higher in patients. An inverse relationship was found in the controls between HbF% with Hb (r = -0.515, p < 0.05) and HbA% (r = -0.534, p < 0.05). In patients, sTfR showed an inverse relationship with HbA% (r = -0.618, p = 0.000) and a positive correlation with HbE% (r = 0.418, p = 0.007) and HbF% (r = 0.469, p = 0.002). Multivariate analysis showed that HbA% (r = 2.875, p = 0.048), HbE% (r = 2.872, p = 0.020) and HbF% (r = 2.436, p = 0.013) best predicted sTfR independently in patients. Thus, sTfR is a useful marker for erythropoiesis. The elevated sTfR in these patients indicate that the transfusion regimen used was inadequate to suppress ineffective erythropoiesis. Hb levels may not be the best target for monitoring transfusion treatment in β-thalassaemia intermedia patients, but the use of sTfR is helpful in individualising transfusion regimens.

Detection of β-globin Gene Mutations Among β-thalassaemia Carriers and Patients in Malaysia: Application of Multiplex Amplification Refractory Mutation System– Polymerase Chain Reaction

Background: β-thalassaemia is one of the most common single-gene disorders worldwide. Each ethnic population has its own common mutations, accounting for the majority of cases, with a small number of mutations for the rarer alleles. Due to the heterogeneity of β-thalassaemia and the multi-ethnicity of Malaysians, molecular diagnostics may be expensive and time consuming. Methods: A simple polymerase chain reaction (PCR) approach involving a multiplex amplification refractory mutation system (MARMS) and one amplification refractory mutation system (ARMS), consisting of 20 β-globin gene mutations, were designed and employed to investigate β-thalassaemia patients and carriers. Results: Out of 169 carriers tested with the MARMS, Cd 41/42 (–TTCT), Cd 26 (A–G) HbE, IVS 1–1 (G–T), and IVS 1–5 (G–C) were the most common mutations, accounting for 78.1%. Among the Malays, Cd 26 (A–G) HbE, Cd 41/42 (–TTCT), IVS 1–1 (G–T), and IVS 1–5 (G–C) were the most common mutations, accounting for 81.4%, whereas Cd 41/42 (–TTCT) and IVS 2–654 (C–T) were most common among the Chinese (79.1%). Conclusion: We propose the use of this cheap, easy to interpret, and simple system for the molecular diagnostics of β-thalassaemia among Malaysians at the Institute for Medical Research (IMR)

HbA2 levels in normal, B-thalassaemia and haemoglobin E carriers by capillary electrophoresis

Objective: The capillary electrophoresis (CE) is a new system that utilizes the principle of electrokinetic separation of molecules in eight electrolyte buffer-fi lled silica capillaries. In this study, we established the normal ranges of haemoglobin A2 (HbA2) and haemoglobin F (HbF) levels for normal individuals using this system and also the HbA2 level in β thalassaemia and haemoglobin E (HbE) individuals. Materials and Methods: 154 samples from normal individuals, 218 samples from β thalassaemia heterozygotes and 91 samples from HbE heterozygotes were subjected to high performance liquid chromatography (HPLC) and CE analysis. Results: The normal ranges for HbA2 and HbF by CE were 2.75% (SD 0.26%) and 0.03% (SD 0.24%) respectively, which were signifi cantly lower than that of HPLC 2.88% (SD 0.25%) and 0.58% (SD 0.61%) (p <0.001). The HbA2 level for HbE heterozygotes was 3.58% (SD 0.44%), which was signifi cantly higher than normal (p <0.001) but lower than that of β-thalassaemia heterozygotes (p<0.001) and the true HbE level was 24.28% (SD 3.38%). Conclusion: The CE system provided a fully automated and high throughput system for haemoglobin analysis. We established the normal ranges for HbA2 and HbF levels by CE. We also determined the ranges for HbA2 in beta thalassaemia and HbE heterozygotes using this system.

Hb E/beta-thalassaemia: a common & clinically diverse disorder.

Haemoglobin E-beta thalassaemia (Hb E/β-thalassaemia) is the genotype responsible for approximately one-half of all severe beta-thalassaemia worldwide. The disorder is characterized by marked clinical variability, ranging from a mild and asymptomatic anaemia to a life-threatening disorder requiring transfusions from infancy. The phenotypic variability of Hb E/β-thalassaemia and the paucity of long-term clinical data, present challenges in providing definitive recommendations for the optimal management of patients. Genetic factors influencing the severity of this disorder include the type of beta-thalassaemia mutation, the co-inheritance of alpha-thalassaemia, and polymorphisms associated with increased production of foetal haemoglobin. Other factors, including a variable increase in serum erythropoietin in response to anaemia, previous or ongoing infection with malaria, previous splenectomy and other environmental influences, may be involved. The remarkable variation, and the instability, of the clinical phenotype of Hb E beta-thalassaemia suggests that careful tailoring of treatment is required for each patient, and that therapeutic approaches should be re-assessed over-time.

Haemoglobinopathies in Southeast Asia.

In Southeast Asia α-thalassaemia, β-thalassaemia, haemoglobin (Hb) E and Hb Constant Spring (CS) are prevalent. The abnormal genes in different combinations lead to over 60 different thalassaemia syndromes, making Southeast Asia the locality with the most complex thalassaemia genotypes. The four major thalassaemic diseases are Hb Bart's hydrops fetalis (homozygous α-thalassaemia 1), homozygous β-thalassaemia, β-thalassaemia/Hb E and Hb H diseases. α-Thalassaemia, most often, occurs from gene deletions whereas point mutations and small deletions or insertions in the β-globin gene sequence are the major molecular defects responsible for most β-thalassaemias. Clinical manifestations of α-thalassaemia range from asymptomatic cases with normal findings to the totally lethal Hb Bart's hydrops fetalis syndrome. Homozygosity of β-thalassaemia results in a severe thalassaemic disease while the patients with compound heterozygosity, β-thalassaemia/Hb E, present variable severity of anaemia, and some can be as severe as homozygous β-thalassaemia. Concomitant inheritance of α-thalassaemia and increased production of Hb F are responsible for mild clinical phenotypes in some patients. However, there are still some unknown factors that can modulate disease severity in both α- and β-thalassaemias. Therefore, it is possible to set a strategy for prevention and control of thalassaemia, which includes population screening for heterozygotes, genetic counselling and foetal diagnosis with selective abortion of affected pregnancies.

Growing up with the families of β-thalassaemia major using an accelerated longitudinal design.

Background & objectives: It is difficult for a single investigator to study the psychosocial changes that occur over the life span of an individual affected with a chronic illness like β-thalassaemia major. Therefore, a developmental epidemiological perspective is required to understand the chain of events and problems of psychological nature. We aimed to construct the picture of developmental epidemiology for psychosocial aspects in families of β-thalassaemia major patients attending a tertiary care hospital in north India. Methods: The accelerated longitudinal design was used. The sample consisted of 100 children with β-thalassaemia and their 150 parents, both groups were subdivided further so that each group represented the continuum of longitudinal course. The sampling was done for a period of 16 months from January 2004 to April 2005. Results: Overall 54 per cent of children had significant psychopathology. Within the parents groups, 10 per cent had adjustment disorder, 33.3 per cent depressive disorder, and 10 per cent had anxiety disorder and 11 per cent somatoform disorder; 95 per cent of the parents of newly diagnosed children expressed feeling of dazed and shock, fear of death, hopelessness, separation anxiety and problems with their memory and concentration. There was significant difference only in the domain of psychological health in all the three groups of parents with respect to the quality of life. Among children, quality of life improved with their progression of illness. Growing up with β-thalassaemic family was analyzed. Interpretation & conclusions: The developmental epidemiological perspective was constructed in β -thalassaemic children and their family using an accelerated longitudinal design. Such a design can test the hypothesized aetiological or developmental function of a targeted risk factor within a developmental path and may be used in studying the psychological impact of even other chronic illnesses over the life span of an individual for conceptual and holistic understanding.

Comparison of fast protein liquid chromatography (FPLC) with HPLC, electrophoresis & microcolumn chromatography techniques for the diagnosis of β-thalassaemia.

Background & objectives: β-thalassaemia is a genetic disorder and an important health problem around the world. Quantitative haemoglobin A2 (HbA2) levels are used for the diagnosis of β-thalassaemia. The conventional methods are high performance liquid chromatography (HPLC), electrophoresis, and microcolumn chromatography techniques. We established a fast protein liquid chromatography (FPLC) method, to measure quantitatively of HbA2 levels, and compared its efficacy with conventional methods. Methods: The FPLC method, using a DEAE Sepharose, Hi Trap anion-exchange column chromatography technique was set up for HbA2 measurement. In this study, 220 blood samples were screened for haemoglobin type by FPLC technique and also using HPLC, microcolumn chromatography and electrophoresis. Results: The FPLC results were highly correlated (r = 0.985, P<0.001) with those of HPLC for quantification of HbA2 as well as cellulose acetate electrophoresis (r = 0.977) and microcolumn chromatography (r = 0.980). The FPLC method showed 100 per cent sensitivity and specificity, positive and negative predictive value for β-thalassaemia diagnosis. In addition, the FPLC method was simple, rapid, low cost and reproducible. The HbA2/E range of FPLC for β-thalassaemia was 6-10 per cent, HbE trait was 10-40 per cent, β-thalassaemia/HbE was 40-60 per cent and homozygous HbE was more than 60 per cent. Interpretation & conclusions: Our findings suggested that FPLC method could be used as a cost-effective method for routine β-thalassaemia diagnosis.

Sickle Cell Haemoglobin, Thalassaemia and G-6-PD Enzyme Deficiency Genes in Garasiya Tribe Inhabited Malaria Endemic Areas of Sirohi District, Rajasthan (India).

Venous blood samples of 368 apparently healthy and unrelated adult individuals (both male and female) belonging to a primitive tribe, Garasiya inhabitating malaria hyperendemic areas of Sirohi district, Rajasthan (India) were investigated by standard and recommended techniques for evidence of erythrocyte genetic disorders; sickle cell haemoglobin, b-thalassaemia syndromes and glucose-6-phosphate dehydrogenase (G-6-PD) enzyme deficiency (Gd). Sickle cell genes encountered in 23 (6.25%) Garasiya tribals. Of these, 22 (5.97%) showed heterozygous sickle cell gene(Hb-AS or trait) and one (0.27%) homozygous form (Hb-SS or sickle cell disease). b-thalassaemia syndromes were observed in 30(8.15%) subjects; 28(7.60%) b-thalassaemia traits (b-thal.) and 2(0.54%) HbS-thalassaemia (HbS-thal.). Gd was found in 56 (15.21 %) subjects. Except these mutant genes no other erythrocyte abnormal genes were encountered in Garasiya tribe. A high incidence or prevalence of these red cell mutant genes in relation to malaria is discussed in the present communication.

Expression of Hb b-T and Hb b-E genes in Eastern India—Family studies.

The distribution patterns of different haemoglobins were observed amongst the family members of β-thalassaemia homozygous and HbE-β-thalassaemia patients with the aid of gel electrophoretic and alkali denaturation techniques. Of the 18 families studied, four belonged to β-thalassaemia homozygous and 14 to HbE-β-thalassaemia patients. Interaction of HbE and β-thalassaemia genes resulted in major clinical abnormalities with increase in the percentages of haemoglobins F and E. The percentages of HbA2 in homozygous β- thalassaemia were within the normal range. Although in Southeast Asia the β° type of HbEthalassaemia is more prevalent, only one individual with this type of thalassaemia was observed during this survey. In the rest of the patients examined the percentages of adult haemoglobin ranged from 5.2 to 42.5 indicating the presence of a b+ type gene.