Haematological status of blood-donors with sickle cell trait and alpha thalassaemia in northern Nigeria

Northern Nigeria is an endemic area for sickle haemoglobin (HbS), and it is common practice in many hospitals to accept blood for transfusion from donors with sickle cell trait (HbAS). In 212 healthy HbAS blood donors, the proportion of HbS was found to range between 24-47%. The HbS levels less than 38% were presumably due to the interaction of sickle-cell gene with the alpha + thalassaemia gene. Low HbS levels and presumed alpha + thalassaemia were associated with significant microcytosis and relatively low Hb A2 and Hb F, but differences were minimal. Carriers of sickle cell trait, with or without alpha + thalassaemia, appear to be acceptable as blood donors. Beta thalassaemia was not detected amongst 710 blood-donors.     

First unaffected pregnancy using preimplantation genetic diagnosis for sickle cell anemia.

CONTEXT: Sickle cell anemia is a common autosomal recessive disorder. However, preimplantation genetic diagnosis (PGD) for this severe genetic disorder previously has not been successful. OBJECTIVE: To achieve pregnancy with an unaffected embryo using in vitro fertilization (IVF) and PGD. DESIGN: Laboratory analysis of DNA from single cells obtained by biopsy from embryos in 2 IVF attempts, 1 in 1996 and 1 in 1997, to determine the genetic status of each embryo before intrauterine transfer. SETTING: University hospital in a large metropolitan area. PATIENTS: A couple, both carriers of the recessive mutation for sickle cell disease. INTERVENTIONS: Standard IVF treatment, intracytoplasmic sperm injection, embryo biopsy, single-cell polymerase chain reaction and DNA analyses, embryo transfer to uterus, pregnancy confirmation, and prenatal diagnosis by amniocentesis at 16.5 weeks' gestation. MAIN OUTCOME MEASURE: DNA analysis of single blastomeres indicating whether embryos carried the sickle cell mutation, allowing only unaffected or carrier embryos to be transferred. RESULTS: The first IVF attempt failed to produce a pregnancy. Of the 7 embryos analyzed in the second attempt, PGD indicated that 4 were normal and 2 were carriers; diagnosis was not possible in 1. Three embryos were transferred to the uterus on the fourth day after oocyte retrieval. A twin pregnancy was confirmed by ultrasonography, and subsequent amniocentesis revealed that both fetuses were unaffected and were not carriers of the sickle cell mutation. The patient delivered healthy twins at 39 weeks' gestation. CONCLUSION: This first unaffected pregnancy resulting from PGD for sickle cell anemia demonstrates that the technique can be a powerful diagnostic tool for carrier couples who desire a healthy child but wish to avoid the difficult decision of whether to abort an affected fetus.     

Neonatal screening for sickle cell diseases in Camberwell: results and recommendations of a two year pilot study

The sickle cell diseases are a major health problem for Afro-Caribbean peoples. Neonatal detection and prophylactic management can reduce mortality and morbidity in childhood. A study was therefore conducted analysing the results of the first two years of cord blood screening in the Camberwell health area. Thirteen cases of sickle cell disease and two of haemoglobin (Hb)C disease were identified among 2202 non-white infants screened. The carrier state, sickle cell trait (HbAS), was present in 11.9% and HbC trait (HbAC) in 4.1% of Afro-Caribbean infants. The incidence of disease and of carrier states was much higher in West Africans than in Caribbeans. The wider implications of screening and the need for a comprehensive plan of care are emphasised.     

The natural history and the national pre-marital screening program in Saudi Arabia

The genetic disorders are chronic in nature and, therefore, require continuous support and health care. Consequently, the genetic diseases cause formidable economic and psychosocial burdens on the family with negative reflection on the community at large. The genetic diseases are a heterogeneous group that result in varieties of chronic health ailment as a result of defects in the genetic material. The congenital malformations and some genetic defects may result from exposure to radiation, pharmaceutical drugs, the exposure of the mother during pregnancy to certain infectious diseases, such as rubella, toxoplasma or viruses. It may also result as a side effect of chronic diseases, including diabetes, hypertension or varieties of environmental factors, or both. The other group of genetic diseases are transmitted from parents to the offspring through a specific pattern of inheritance exemplified by recessive genetic disorders. This group includes the sickle cell gene, the thalassemias, the hemophilias, inborn errors of metabolism and red cell enzymopathies. The main etiological factors of genetic diseases and congenital malformations are 1) Genetic defects which are transmitted to offspring through carriers of affected parents. 2) Mutations in the genetic materials due to spontaneous mutations, exposure of the mother during pregnancy to infectious diseases, such as rubella and toxoplasma, receiving certain teratogenic drugs during pregnancy, exposure of the mother to ionizing radiation during pregnancy such as x-ray and chronic diseases of the mother, such as diabetes mellitus. 3) Others such as difficult labor or injury to the baby, during or after labor. This paper reviews the natural history of common blood genetic disorders and the means of prevention and control, focusing on pre-marital screening as a means of prevention.     

Pregnancy outcome in women with sickle cell trait

A prospective study was carried out to discern the outcome of pregnancy and distribution of birth weights of infants delivered of 85 women with sickle cell trait (AS) compared with a control group of 85 women with normal hemoglobin (AA) who were matched for race, age, parity, and sex of offspring. The distribution of birth weight of offspring of primiparous and multiparous women and the proportion of low-birth-weight infants did not differ significantly between infants born to mothers with AS and those in the control group. Similarly, there was no statistically significant difference between the birth weight of infants born to primipara or multipara. Also, the overall incidence of complications among women with AS did not differ from the incidence in the control group. The findings do not support previous reports that there may be definable pathologic correlates of childbearing in women with AS.     

应用荧光聚合酶链反应对α地中海贫血进行植入前遗传学诊断

目的探讨应用跨越断裂点荧光聚合酶链反应（PCR）技术在α地中海贫血（简称α地贫）植入前遗传学诊断（PGD）中的应用。方法获取Ot地贫东南亚缺失型携带者单个淋巴细胞,建立了稳定的单细胞跨越断裂点荧光PCR检测技术,并对4对夫妇双方均为α地贫——SEA缺失型杂合子应用荧光PCR进行了α地贫的PGD。结果单个淋巴细胞平均扩增效率为90．0％（72／80）,平均等位基因脱扣（ADO）率为8．3％（6／72）。对4对夫妇进行4个周期PGO,共检测38个胚胎,获得38个卵裂球,其中34个卵裂球扩增成功,扩增效率为89．5％（34／38）,ADO率为5．9％（2／34）。经PCR分析,共获得11个正常胚胎,8个杂合子胚胎,15个重型地贫胚胎。移植了11个胚胎,获得2例临床妊娠。孕17周时经脐带血穿刺,分别证实为完全正常胚胎和杂合子胚胎,现已出生两名健康男婴。结论应用单细胞荧光PCR技术可对α地贫进行植入前遗传学诊断,达到优生的目的。     

In vitro fertilisation in a small unit in the NHS

In vitro fertilisation is one of the most effective new treatments for infertility, but financial restrictions have made it impossible for it to be widely carried out in the National Health Service. We report on the establishment of a small, largely self funded, unit that was set up with the help of the local health service management. All cycles are programmed so that most work is carried out during the working week; oocyte recoveries are performed as outpatient procedures without general anaesthesia and guided by ultrasound. Roughly a tenth of treatment cycles and roughly a fifth of embryo transfers resulted in a clinical pregnancy.     

In vitro fertilisation in domestic mammals—a brief overview

Many factors influence the final oocyte maturation, fertilisation, and early embryo development, and there are both similarities and differences between species. When comparing the advancement of assisted reproductive technologies (ARTs), the development in the bovine species is not far behind the medical front, with around one million in vitro-produced bovine embryos each year. This rate of progress is not seen in the other domestic species. This review aims to give an overview of the development and specific difficulties of in vitro embryo production in various domestic animal species, with the main focus on cows, pigs, and cats. In production animals, the aim of ARTs is commonly to increase the genetic progress, not to treat reproductive failure. The ARTs are also used for preservation of genetic diversity for the future. However, specifically for oocyte maturation, fertilisation, and early embryonic development, domestic mammals such as the cow and pig can be used as models for humans. This is particularly attractive from an animal welfare point of view since bovine and porcine oocytes are available in large numbers from discarded slaughterhouse material, thereby decreasing the need for research animals. Both for researchers on the animal and human medical fronts, we aim for the development of in vitro production systems that will produce embryos and offspring that are no different from those conceived and developed in vivo. Species-comparative research and development can provide us with crucial knowledge to achieve this aim and hopefully help us avoid unnecessary problems in the future.     

Avascular necrosis of the femoral head in sickle cell disease in Nigeria: a retrospective study

BACKGROUND: Avascular necrosis (AVN) especially of the femoral head, has long been recognised as a manifestation of sickle cell disease (SCD). Despite this knowledge the actual prevalence of this complication among sickle cell patients in Nigeria is not known. OBJECTIVE: To determine the prevalence and patterns of presentation of avascular necrosis of the femoral head in sickle cell disease. PATIENTS AND METHODS: A retrospective study carried out at the Orthopaedic and Haematology clinics of Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria. Four hundred and sixteen patients with sickle cell disease seen over a 15-year period. RESULTS: Of the 416 patients with sickle cell disease 340 (81.7%) had haemoglobin SS genotype while 76(18.3%) had SC genotype. Sixty-six (15.9%) patients 35 males (53%) and 31 females (47%) had clinical and radiologic features of avascular necrosis (AVN) of the femoral head. Fifty-three of them (80.3%) had Hb SS while 13 had Hb SC. The peak age incidence in both Hb SS and Hb SC was 21-30 years. Forty patients (60.6%) presented with stage IV disease (Ficat and Arlet Staging) while 21.2% had stage III and 18.2% had stage II. No patient was diagnosed in stage 1 or 0. CONCLUSION: The prevalence of AVN of femoral head in Hb SC and HbSS is similar i.e. the difference is not statistically significant (P=0.48). Most of our patients present late with advanced diseases. Considering the paucity of facilities available for total hip replacement in Nigeria and the young age group affected we recommend regular screening of patients with sickle cell disorder for AVN and regular community educational programmes for early diagnosis.     

Preimplantation diagnosis for Fanconi anemia combined with HLA matching.

CONTEXT: The advent of single-cell polymerase chain reaction (PCR) has presented the opportunity for combined preimplantation genetic diagnosis (PGD) and HLA antigen testing. This is a novel and useful way to preselect a potential donor for an affected sibling requiring stem cell transplantation. OBJECTIVE: To perform in vitro fertilization (IVF) and preimplantation HLA matching combined with PGD for Fanconi anemia (FA). DESIGN: DNA analysis for the IVS 4 + 4 A-->T (adenine to thymine) mutation in the FA complement C (FANCC) gene in single blastomeres, obtained by biopsy of embryos, to identify genetic status and HLA markers of each embryo before intrauterine transfer. SETTING: In vitro fertilization programs at large medical centers in Chicago, Ill, and Denver, Colo. PARTICIPANTS: A couple, both carriers of the IVS 4 + 4 A-->T mutation in the FANCC gene with an affected child requiring an HLA-compatible donor for cord blood transplantation. MAIN OUTCOME MEASURES: DNA analysis of single blastomeres to preselect unaffected embryos representing an HLA match for the affected sibling. RESULTS: Of 30 embryos tested in 4 IVF attempts, 6 were homozygous affected and 24 were unaffected. Five of these embryos were also found to be HLA-compatible, of which 2 were transferred in the first and 1 in each of the other 3 cycles, resulting in a pregnancy and birth of an unaffected child in the last cycle. CONCLUSION: To our knowledge, this is the first PGD with HLA matching, demonstrating feasibility of preselecting unaffected embryos that can also be an HLA-compatible source for stem cell transplantation for a sibling.     

Knowledge of and attitudes to sickle cell disease and sickle carrier screening among new graduates of Nigerian tertiary educational institutions

Six hundred and ten new graduates of Nigerian tertiary institutions were studied for their knowledge of and attitude to sickle cell disorders. A questionnaire was administered to assess knowledge and attitudes. Then a two-hour educational seminar on the basic genetics, transmission, and implications for the affected individuals and their families, of sickle cell disease (SCD) and carrier states was conducted. Sickle carrier screening was undertaken by cellulose acetate haemoglobin electrophoresis. A sickle carrier frequency of 21.6% was found and the questionnaires revealed severely deficient knowledge of the transmission of SCD among the 20-32 year old graduates. After the seminar there was eagerness among the graduates to know their sickle status. It is concluded that unmarried youths in, or graduating from, higher educational institutions may be a most suitable target for information, carrier detection and genetic counselling in the prevention and control of sickle cell disorders.     

In vitro fertilisation: the major issues--a comment

Mitchell, a sociologist, comments on a companion paper on in vitro fertilization by Peter Singer and Deane Wells. He criticizes the failure of Singer and Wells to consider the deleterious effects on society and on the children of artificial reproduction involving donated sperm or ova and accuses them of placing the desire of the individual to have a child above the good of society and of future generations. Singer, in a brief response, defends his utilitarian argument that reproductive technologies should be available to all. He does not consider knowledge of one's genetic identity to be a crucial issue, pointing out that the child's alternative is no existence at all.     

CD4+ T Lymphocytes count in sickle cell anaemia patients attending a tertiary hospital

Background:

Sickle cell haemoglobin (HbS) is the commonest abnormal haemoglobin and it has a worldwide distribution. Reports have shown that patients with sickle cell anaemia (HbSS) have an increased susceptibility to infection leading to increased morbidity and mortality. Impaired leucocyte function and loss of both humoral and cell-mediated immunity are some of the mechanisms that have been reported to account for the immunocompromised state in patients with sickle cell disease. This study was carried out to determine the CD4+ T lymphocytes count in patients with sickle cell anaemia.

Materials and Methods:

A comparative cross-sectional study of 40 sickle cell anaemia patients in steady state (asymptomatic for at least 4 weeks) attending haematology clinic and 40 age and sex-matched healthy HbA control were recruited into the study. Both HbS patients and the controls were HIV negative. The blood samples obtained were analyzed for CD4+ T cell by Flow cytometry.

Results:

The study found that there was no significant difference in the number of CD4+ T lymphocyte count between individuals with sickle cell anaemia and HbA (1016 ± 513 cells/μL vs 920 ± 364cells/μL).

Conclusion:

It is recommended that the functionality of CD4+ T lymphocyte should be considered rather than the number in further attempt to elucidate the cellular immune dysfunction in patients with sickle cell anaemia.     

Preimplantation genetic diagnosis of chromosomal abnormalities by multicolour fluorescence in situ hybridisation

Preimplantation genetic diagnosis (PGD) is an early diagnosis of genetic disorders, prior to the onset of pregnancy. PGD incorporates the latest techniques in assisted reproduction and molecular genetics. Embryos or oocytes are biopsied during culture in vitro and genetic analysis is carried out on the blastomeres or polar bodies. Embryos shown to be free of the genetic disease under investigation are transferred to the uterus. Multicolour fluorescence in situ hybridisation (FISH) is used to diagnose numerical and certain structural abnormalities of chromosomes in the embryo. The common probes used are for chromosomes 13, 18, 21, X and Y. FISH can also be used for PGD of translocations, when one of the parents is a carrier. PGD was carried out recently in 4 cases using multicolour FISH. In one of the embryos, trisomy 18 was detected. Tetraploidy was seen in another embryo. Only chromosomally normal embryos were transferred back to the uterus. Care has to be taken while interpreting FISH signals as the signal may be split, diffused, superimposed or in a different focus.     

13q33LOC122330位点与精神分裂症的关系

目的 :在中国北方汉族精神分裂症患者和其健康父母组成的 1 0 5个核心家系中探讨1 3q33LOC1 2 2 330位点与精神分裂症的关系。方法 :从全血中提取基因组 DNA,应用 PCR- RFLP方法检测 LOC1 2 2 330位点编码序列第 864个碱基从异亮氨酸到蛋氨酸的错义突变单核苷酸多态性 ( rs942 35 8)的分布。结果 :1 rs942 35 8基因型频率的分布符合 Hardy- Weinberg平衡 ;2单倍型相对风险分析 ( HRR)表明 ,rs942 35 8与精神分裂症无关联 (χ2 =0 .61 9P>0 .0 5 ) ;3传递不平衡检验( TDT)显示 ,父母和受累子女之间不存在显著的传递不平衡 (χ2 =0 .2 2 2 ,P>0 .0 5 ) ,即杂合父母传递给受累子女的等位基因无差异 ;4等位基因频率与精神分裂症的各种临床症状不相关。结论 :LOC1 2 2 330位点 rs942 35 8可能与精神分裂症无关 ,但不能排除该位点其它 SNPs与精神分裂症有关联     

Biochemical diagnosis in sickle cell disease

Seventy-four sicklers with bone pain had blood taken for biochemical analysis of the haemoglobins carried. Sixty-five patients with sickle cell disease diagnosed as Hb S/S disease, five patients diagnosed as Hb A/S and four patients with three haemoglobin bands corresponding to Hb's A, S and C were used in this quantitative reassessment on cellulose acetate. Haemoglobin A2 level was determined in all cases and alkali resistant haemoglobin level in twenty-nine cases. The significance of raised Hb A2 levels in some of these cases is discussed with relation to the possible existence of Hb S/beta-Thalassaemia in the sickle cell disease patients examined.     

对曾育21三体综合征患儿者行胚胎种植前遗传学诊断获妊娠1例

目的 在体外受精－胚胎移植过程中，对高危夫妇进行胚胎种植前遗传学诊断以避免21三体综合征患儿的出生。方法 常规激素替代治疗，对患者夫妇行胞母细胞质内精子注射（ICSI），正常受精培养到第3天，对6－10细胞期胚胎活检1个细胞，利用荧光原位杂交技术（FISH）进行胚胎种植遗传学诊断（PGD），挑选染色体数目正常的胚胎移植入患者子宫。结果 共对8个胚胎进行PGD，7个有诊断结果者中7个为正常胚胎、1个为21三体胚胎。挑选3个胚胎移植，获得妊娠并产下一健康男婴。结论 应用FISH对染色体数目的遗传疾病，如21三体综合征，进行胚胎种植前遗传学诊断是切实可行的。     

Single Cell Analysis of Dystrophin and SRY Gene by Using Whole Genome Amplification

Objective To develop a reliable and sensitive method for detection of sex and multiloci of Duchenne muscular dystrophy (DMD) gene in single cell Materials & methods Whole genome of single cell were amplified by using 15-base random primers (primer extension preamplification, PEP), then a small aliquot of PEP product were analyzed by using locus-specific nest PCR amplification. The procedure was evaluated by detection dystrophin exons 8, 17, 19, 44, 45, 48 and human testis-determining gene (SRY)in single lymphocytes from known sources and single blastomeres from the couples with no family history of DMD.Results The amplification efficiency rate of six dystrophin exons from single lymphocytes and single blastomeres were 97. 2% (175/180) and 100% (60/60) respectively.Results of SRY showed that 100% (15/15) amplification in single male-derived lymphocytes and 0% (0/15) amplification in single female-derived lymphocytes. Conclusion The technique of single cell PEP-nest PCR for dystrophin exons 8, 17,19, 44, 45, 48 and SRY is highly specifc. PEP-nest PCR is suitable for Preimplantation genetic diagnosis (PGD) of DMD at single cell level.     

The immunological aspects of sickle cell syndrome with particular reference to circulating immune complexes

A concise but critical review of the literature on the immunological aspects of sickle cell syndrome (SCS) was carried out. This exercise revealed our poor understanding of the immune status of these persons, while most of them succumb to overwhelming infections. We used laser nephelometric technique to quantitate the C4. Unlike the serum IgM complex, we found that IgG and IgM were raised in these persons. However, a significant rise in serum IgM was noted during the symptom of vaso-occlusive painful crisis. The profile of complement protein consumption correlated positively with the levels of the immune complexes. We suggest that sickle cell persons are generally more susceptible to immune complex pathology and the possible contribution of IgM to the symptom of vaso-occlusive painful crisis was discussed.     

Folate levels in children with sickle cell anaemia on folic acid supplementation in steady state and crises at a tertiary hospital in Enugu,Nigeria: a prospective,comparative study

IntroductionFolic acid supplementation is an integral aspect of the management of children with sickle cell anaemia (SCA) especially in Africa. In spite of this, there have been concerns about lower folate levels, especially during crisis.AimTo determine red cell folate levels of children with sickle cell anaemia in steady state and during crisis and compare with those with haemoglobin AA genotype.MethodThis study was prospective, hospital based, and comparative. Fifty children with sickle cell anaemia were recruited during crises and followed up until they met the criteria for attaining steady state. The controls were fifty children matched with those with SCA for age and gender and had haemoglobin AA genotype. Red cell folate estimation was done with the Electrochemiluminescence Immunoassay (ECLIA) method using the automated Roche Cobas e411 equipment.ResultsThe median (IQR) red cell folate level in children during sickle cell crisis was 265.95 (134.50) ng/ml, which was significantly lower than the median (IQR) of 376.30 (206.85) ng/ml obtained during steady state. Most children with SCA (41 out of 50) had significantly higher folate levels during steady state (T=1081, Z-score= -4.660, p < 0.001). Median level of red cell folate was lower during anaemic crisis compared to vaso-occlusive crisis, though not significantly so (N(50), U = 214.00, Z-score= -1.077, p = 0.305). The median red cell folate level of normal controls was 343.55 (92.90) ng/ml, which was significantly lower than the 376.30 (206.85) ng/ml obtained during steady state (N(50), U= 209.00, Z-score= -7.177, p <0.001).ConclusionMedian red cell folate levels of the study participants were within normal limits, though most children with SCA had significantly higher levels during steady state compared to crisis. Normal controls had significantly lower red cell folate levels than the children with SCA during steady state.