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Biomedical subjects

B Modell

Publications and source records attributed to B Modell.

At least 19 recordsLinked to original sources
PubMed1992

Alpha thalassaemia hydrops fetalis in the UK: the importance of screening pregnant women of Chinese, other South East Asian and Mediterranean extraction for alpha thalassaemia trait.

OBJECTIVE: Alpha zero (alpha 0 or alpha-1) thalassaemia is an important genetic risk for women originating from Hong Kong, Singapore, Vietnam, Thailand, the Philippines or South China. Cypriots are also at risk. Carriers of alpha zero thalassaemia trait can be detected by routine haemoglobinopathy screening. When a couple are both carriers, in each pregnancy there is a 25% risk that the fetus will have alpha thalassaemia hydrops fetalis; this is fatal for the fetus and carries serious obstetric and psychological risks for the mother. Most informed couples at risk request prenatal diagnosis and selective abortion. This study investigates the effectiveness of screening, counselling and prenatal diagnosis for alpha thalassaemia hydrops fetalis in the UK. DESIGN: Retrospective analysis of the notes. SUBJECTS: 18 couples attending University College Hospital London for prenatal diagnosis of alpha thalassaemia hydrops fetalis since 1982. RESULTS: The study shows underdiagnosis of both alpha zero thalassaemia trait and alpha thalassaemia hydrops fetalis leading to avoidable stillbirths and complications in pregnancy. CONCLUSION: We recommend early screening for alpha zero thalassaemia trait for all women of Southeast Asian or eastern Mediterranean origin and the offer of prenatal diagnosis when indicated. The diagnosis of alpha thalassaemia hydrops fetalis should be considered in women of the relevant ethnic origin who have a stillbirth, neonatal death, abnormal ultrasound findings at fetal anomaly scanning (especially a large placenta), or who develop pre-eclampsia.

Abortion, Spontaneous↗
PubMed1992

Factors affecting the uptake of prenatal diagnosis for sickle cell disease.

Between 1979 and 1990, 170 couples at risk of having children with sickle cell disease, resident in the UK and with a continuing pregnancy, were referred for counselling at the University College Hospital Perinatal Centre. Approximately 50% of the couples, including those where one partner actually had sickle cell disease, requested prenatal diagnosis. This was requested in 82% of pregnancies when the mother was seen in the first trimester of pregnancy and in 49% when she was seen in the second trimester. More than 90% of referred couples who already had an affected child requested prenatal diagnosis. The type of sickle cell disease involved and ethnic group also influenced choice. These results show the importance of detecting and counselling couples at risk before pregnancy whenever possible.

Anemia, Sickle Cell↗
PubMed1992

Ethical aspects of genetic screening.

Public and professional concern associated with the idea of genetic screening has generated numerous publications on the ethics of genetic screening (e.g. 1-4). Concerns revolve around inadequate consultation before screening is carried out, the unearthing of worrying risks, the use of genetic information in ways that could be disadvantageous to the person involved, stigma, and a phenomenon known as the 'technological imperative', which means that simply because a technology is available there is a tendency to use it. Most reports agree that, in practice, the main ethical problems are likely to involve screening for risk of common diseases of adult life, because of the possible impact on a person's healthy self-image, implications for health and life insurance, and the possibility of commercial exploitation of people who know themselves to be vulnerable. In this paper I do not propose to address these issues directly. I have been invited to discuss this subject as a clinician involved with genetic screening, counselling and prenatal diagnosis for the haemoglobin disorders, the most common serious human recessively inherited diseases. Since we are scientists, any recommendations we make should be based on experience: my aim is to show that experience is often surprising, and that it is often possible to meet public concerns by taking quite simple practical steps.

Ethics, Medical↗
PubMed1991

Transfusion requirements and effects in patients with thalassaemia major. Cooleycare Programme.

Analysis of data available in 1985 on 3468 Italian and Greek patients registered in Cooleycare, an international cooperative programme of quality assessment of treatment delivery in thalassaemia, gave the following picture of treatment requirements and effects. The proportion of patients undergoing splenectomy has progressively decreased, and age at splenectomy has increased with time over the past 20 years. Age at first transfusion exceeds 4 years in a small but important group of patients, which indicates that a milder form of thalassaemia exists in this group. Children receiving modern treatment remain of near-normal stature until age 11 but later tend to be stunted. The mean blood requirement is 35% higher in non-splenectomised than in splenectomised patients. Differences in transfusion interval of 2 to 4 weeks have no measurable effect on blood requirement. Mean blood requirement rises gradually with mean haemoglobin concentration, possibly in a non-linear fashion. The prevalence of red cell alloimmunisation rises with delay in start on transfusion. Transfusion reactions were reported in 1% of transfusions (90% of which were leucocyte-depleted), from 17% of patients.

Adolescent↗
PubMed1990

Changing paternal age distribution and the human mutation rate in Europe.

All available evidence indicates that the human mutation rate increases with paternal age. In developed countries, a reduction in the proportion of older parents is a common feature of the marked changes in parental age distribution that occur as a result of family planning. We have related the current paternal age distribution in the European countries for which data is readily available, to a derived curve for paternal age-specific relative mutation rate. The results indicate that, to the extent that it is dependent on paternal age, the mutation rate has decreased considerably in developed countries during the past 50 years. The human mutation rate is a dynamic entity, continuously changing in response to social conditions.

Adult↗
PubMed1990

Problems in the control of genetic disorders.

Preventive genetics services based on population screening are now an integral part of maternal and child health programmes. New developments in DNA technology, ultrasound scanning, and assay of factors in maternal blood are greatly increasing their potential to improve human health. If these services are to be delivered fairly to populations, there must be much more emphasis on community information, professional education, and service monitoring.

Consanguinity↗
PubMed1990

The ethics of prenatal diagnosis and genetic counselling.

Doctors are often censured for the aborting of severely abnormal fetuses after prenatal diagnosis. But, where parents have been left in ignorance and have produced an abnormal child, there has been a very strong sense of injustice. The moral responsibility must ultimately rest with the parents, who must have control of their own health and that of their families.

Abortion, Induced↗
PubMed1990

Thalassemia in Bombay: the role of medical genetics in developing countries.

This study of 200 families with thalassaemic children in Bombay showed that these children's treatment and needs place a significant, unavoidable and increasing demand on the public health services. At the same time, owing to the potentially large number of patients and the difficulties of long-term management, the situation is characterized by evasion of the problem, failure of planning, no provisions for prevention, and inadequate treatment leading to premature death among the affected children. The burden on such families is greater in developing than in developed countries because, besides caring for the chronically sick child, their lives are dominated by the high costs of treatment, often amounting to 20-30% of the income for many families. Seven mothers with no healthy children and 27 with only one healthy child had been sterilized; 90% of reproductive-age couples felt that prenatal diagnosis was a necessity. Also, ignorance and prejudice in the community led to social isolation for forty families. The experience in Europe shows that improved treatment is the key step in controlling thalassaemia. A well-organized day-transfusion service is cost-effective, soon restoring the children to health and leading to increased optimism. The formation of associations by parents could mobilize community support for improved treatment and prevention, and increase public awareness of the problem. Thus cost-effective management and prevention through screening, genetic counselling, and prenatal diagnosis are at least as important in the developing as in developed countries.

Adolescent↗