In the annals of research into Human Biology in Sri Lanka , the establishment of a National Twin Registry is indeed a signal achievement of great significance. if not for the wisdom, courage, passion, commitment and steadfast resolve of two of our Sri Lankan scientists, Dr. Athula Sumathipala and Dr. Devaka Fernando, this original embryonic thought would never have had such a healthy period of gestation and this momentous birth.
We in Sri Lanka, have been sitting on a treasure trove of twin material, either in ignorant bliss or in a state of muted awareness, and today, with this launch we shed that grab of indifference and ignorance into a new world of research.
Anthropologically, Sri Lanka , is one of the most interesting islands in the world, with considerable genetic diversity between the five main populations, due to the contribution of ancestral and immigrant of European and Asian origin. In this scenario, the many basic research projects in human biology that have been carried out, have always had to contend with and at times confront a perennial problem. That being the determination of whether the human biological variation one encounters, is a direct impact of the genetic constitution or the influence of a wide spectrum of a wide spectrum of environmental forces that control the final outcome of a physiological process, a parameter or a stage of development. With the availability of a twin registry in Sri Lanka , I hope, the reign of these unanswered questions will soon end, as twin studies will allow and encourage scientists, to burrow deep into that aspects of science, which for many years did elude them.
It is my fervent and twin hope, that the launching of this project, the scientific community will hope, that with the launching of this project, the scientific community will cooperate and assist in its functioning and that the outcome of research projects launched from it, will not merely test an esoteric thought or a lame hypothesis, but will make realistic and useful contribution to the upliftment of the health status of our country.
Research using twins has thrown light on many areas of medicine. Thus, twin studies have helped researchers to estimate the relative contributions of genes and environment to diseases as disparate as coronary artery disease, diabetes and schizophrenia. A relatively recent example in psychiatry is autism. Formerly. autism was thought to be largely an environmentally determined disorder. However, twin studies have shown that identical twins show very high concordance rates for this disorder, and provided the first evidence that it is highly genetically controlled.
In addition to the classical comparisons of concordance rates in monozygotic and dizygotic twins, identical twins discordant for a disorder can also provide invaluable evidence as to the pathogenesis of a condition. For example, studies of twins discordant for schizophrenia provided the crucial evidence that schizophrenia itself is associated with structural abnormalities of the brain ( e.g , ventricular enlargement and decreased volume of the temporal lobe), and that these cannot be wholly explained by genetic predisposition; early environmental factors, such as pre- or perinatal complications, must be involved.
Hitherto, nearly all twin registers have been based in highly industrialised developed countries. Consequently, the research largely pertains to white populations. The new Twin Register being established in Sri Lanka is a welcome break with this tradition. It will open up many opportunities for valuable research in Sri Lanka, and no doubt the findings will have much to teach us in the West.
I started the Australian Twin Register (ATR) in 1978 with John Mathcws and we jointly recruited 16,000 twins by 1980. In the same year we attained funding from the NHMRC to support the register as a resource for biomedical research. We have been supported ever since and currently the annual grant is about $80,000 a year for recruitment and updating of records and support of individual biomedical researchers around the country. In any one year there are up to 30 projects using the ATR across the whole spectrum of biomedical research, from psychology to immunology and dentistry.
The ATR is run by a small secretariat and the current director is Dr John Hopper at the Department of Community Medicine in the University of Melbourne. A major new focus of interest is the value of DZ twins as sib pairs for linkage studies. Collecting data on siblings, parents, spouses and offspring of twins, we are currently screening more than 1 0,000 twin and sib pairs already measured for neuroticism to select extreme samples who will be useful for finding qualities for anxiety and depression. We are also taking part in a collaborative project involving 16 twin resisters in Europe, the United States and Australia on the genetics of cleft lip and palate.
I was delighted when I first heard of the project as I knew of no other in the developing world, and this will be a most valuable tool for international cross-cultural collaborations. Best wishes.
Most people, including professionals in the fields of health, welfare and education, have little idea just how demanding twins, triplets and higher multiple birth babies can be. All too often, the parents' natural joy in their twins and their ability to cope are dramatically reduced by the complex problems that frequently arise. Even when all the children are healthy, parents have to cope with greater practical and financial demands andthe special emotional difficulties of relating to two or more babies at the same time. Behavioural and developmental problems are also more common than in singletons.
The MBF is the only professional service in the UK (and, so far, anywhere) that specialises in the problems and needs of twins and higher order births and the support of their families. It is a part of the Institute of Obstetrics and Gynaecology Trust, based at Queen Charlotte's and Chelsea Hospital in London. it holds regular Twins Clinics in London, Birmingham and York and its nation-wide Telephone Advisory Service enables (often isolated and immobilised ) families to establish direct contact with sympathetic and experienced professionals. Much of the work is aimed at preventing or ameliorating the typical problems of multiples such as delayed language development or growth; of individuality and behavioural problems such as excessive rivalry, dominance or dependency. There can also be serious difficulties far adolescent twins in achieving their individual autonomy and a harmonious separation in adulthood. Professional carers , like family doctors, health visitors and teachers, inevitably have only limited experience of multiples and the Foundation's education and training programme provide advice about their special nature and needs and those of their families. Such advice is also highly relevant to the work of infertility clinics - so many of whose offspring are twins or more. We wish this new venture every success and look forward to collaboration in the future.
E. Bryan MD MRCPCH FRCP S - Medical Director
Denton RGN RM - Nursing Director
We are delighted that a twin registry is starting up in Sri Lanka and are keen to share our experiences with you and help integrate our registries as much as possible for mutual benefit.
We started our London based adult registry in 1991 with two staff and now have about 6000 adult twins on our books and employ 40 staff. We see clinically about 1000 pairs of twins a year who come to visit the unit from all around the country. During their 6 hour visit the twins have a full medical check up and are assessed for most of the common diseases associated with ageing. We have a number of world wide collaborations with a wide range of specialities around the world and have large numbers of research grants. We have helped set-up similar twin centres in Sydney and Brisbane in Australia so that we can combine our data using the same protocols. We now have a wealth of information on the role of lifestyle and genes in many diseases ranging from asthma, backpain , arthritis, menopause, diabetes, obesity and osteoporosis.
We wish Sri Lanka every success in this exciting and innovative project and look forward to many years of collaboration and exchange of ideas and staff to compare diseases in our two countries.
Message from Prof. Robert Plomin , Deputy Director
Social, Genetics and Developmental Psychiatric Research Centre, Institute of Psychiatry, University Of London, U.K.
Best wishes for the launch of the Sri Lankan Twin Register!
I conducted a twin study for my dissertation research and have been involved in several longitudinal twin studies for the past 15 years using registers in Colorado (USA) and Sweden. The sampling frame for my current study is all the twins born in England and Wales in 1994, 1995, and 1996. About 5,000 pairs from the 1994 birth cohort are currently participating and we are now enrolling the 1995 birth cohort. The focus of the study is mild mental impairment, including language and non language cognitive delays. We are attempting to obtain DNA from all twins in order to merge quantitative genetics and molecular genetic approaches.
TWIN REGISTERS FOR CHILD PSYCHOPATHOLOGY
Amongst parents' concern regarding their children's health and development, problems related to their behavioural and emotional status and highly, because they are common problems. Similarly, in many countries, a substantial proportion of the health and social services budgets that relate to children focus on children with psychopathology. Within education, behaviour problems are frequently the cause of or are associated with special needs. Therefore, psychopathology is an important area in which to focus research attention. Although the ultimate goals will be in effective prevention and intervention, our understanding if the causes of and maintaining factors for psychopathology is limited. For example, their is little understanding of why males are at greater risk for many child psychiatric and developmental disorders. Does this reflect a greater constitutional vulnerability for males or are Post-natal treatment differences the primary explanation? Similarly, the aggregation of multiple disorders both with in the individual [comorbidity] and with in the family have not been well studied. Are genetic risk factors for child psychopathology expressed in a mulititude of ways [ pleiotropy ] or are their shared environmental risk factors, such as family discord and poverty, which predispose to wide variety of disorders? These are but two of the compelling questions that require answers.
Twin studies are a key research design for trying to disentangle the nature of mechanisms involved in the development and resistant of psychopathology. There are now a number of large- scale twin studies which have as there main focus the study of child psychopathology and related problems. Two studies, in which I am involved are the Virginia Twin Register of Adolescent Behavioural Development [VTSABD] and the twins' Early Development Study [TEDS]. VTSABD involves a general population chort -longitudinal study of twins aged 8-16 years residing in the state of Virginia [USA] The study focuses on risk factors for the development, maintenance and desistence psychopathology, measured both categorically through psychiatric interviews, and demensinonally , through questionnalries . TEDS is develop from a register of all twins born in England and Wales between 1994 -1996 and follows their mental and emotional/ behavioural development over the first four years of life. Both studies are sufficient magnitud to study common disorders measured categorically, as well as to behavioural traits.
I would encourage the Sri Lanka Twin Register to make child psychopathology a particular research focus. There is now ample experience in the measurement of psychopathology in large samples and in twins, providing a base to use comparable measures and to examine cross-cultural differences. It is an area in which genetic but particularly environmental variation cross- culturally is likely to lead to different results, which will further increase our understanding of the processes involved. I should be happy to collaborate in whatever way seems most helpful.