Aldur W. Eriksson, the noted twin scholar and human geneticist, passed away on Friday, April 3, 2015, at the age of 88. He had a full, highly productive and accomplished life. He is survived by his wife Maj-Britt and their son Staffan and his family. His death leaves a void, not only among relatives and friends, but among the many who had known him and in the scientific community, particularly that of twin researchers worldwide.
Aldur was born on April 7, 1927 in the north-western part of the Åland Islands as the fourth and youngest child in a farmer family. He was very active and loved exercise; he practiced athletics at school, mainly as sprinter, and continued to exercise all of his life, although in later years, following a traffic accident, he could no longer practice and even had to use a walking stick.
After graduating at the Åland's Lyceum in 1948, he studied medicine at the University of Helsinki and got his MD in 1956. He showed an early interest in research and soon joined research groups. His first notable results regarded two genetic disorders characteristic of the Åland: von Willebrand's disease (hemophilia that strikes both sexes) and the Åland Island eye disease (Forsius-Eriksson's syndrome); he also took part in studies on the X-chromosomal recessive retinoschisis. He then organized scientific expeditions to study genetically isolated populations, particularly in Iceland, Greenland, the Åland, Finnish Lapland, and some Finno-Ugric areas in Russia.
Already in 1960, he had an Honorary prize from the Association of Finnish Physicians. He then became Head of the Population Genetics Unit at the Folkhälsan Institute of Genetics in Helsinki (1963–1973); Research assistant (1964–1967), then Research scientist (1967–1973) at the Finnish National Research Council for Medical Sciences; Medical Doctor of Science and Docent of Medical Genetics at the University of Helsinki (1973).
In 1973, he was appointed Professor and Head of the Human Genetics Institute at the Medical Faculty, Free University of Amsterdam where he worked for the next 21 years, until his retirement in 1994, and where he was instrumental in facilitating blood and DNA collection in the first families recruited into the Netherlands Twin Register. Then, he returned to Finland, to the Folkhälsan Institute of Genetics, the institute from which he had started.
Aldur was very productive and published intensively throughout his life (with 664 titles from 1956 to 2014), besides taking part in numerous expeditions, international congresses and other meetings and activities. He was also active as an editor, referee, and in administrative roles; he was a member of many associations, and received several scientific recognitions.
Aldur's interest in twin research started at an early stage, with papers such as ‘Variations in the human twinning rate’ (1962), ‘Twinning and legitimacy’ (1967), and several others in the same vein. His thesis, Human twinning in and around the Åland Islands (1973), was for him of great value. The region was his home district and showed for 300 years high or occasionally very high twinning rates, with strong regional variations between the island isolates. These findings inspired him to conduct extensive studies on the variability of twinning rates and the role played by the various factors –– population diversity, isolation, heredity or socioeconomic aspects –– an area of study which characterized much of his work throughout his life.
When he retired, in order to honor his scientific career, the University of Amsterdam organized an International Symposium on the Genetic Epidemiology of Twins and Twinning (Amsterdam, April 22–23, 1994). And when he then came back to Finland to the Folkhälsan Institute of Genetics, research on twinning rates was his main interest, which he could pursue even without access to advanced laboratories, conducting surveys and statistical studies. In the 1950s, Aldur had ‘inherited’ a large data set on triplets from the late Maija Miettinen, consisting of the families of almost all triplets born in Finland between 1905 and 1959. He tried to complete the data and followed up the triplets after the 1950s. He also widened the scope by investigating other aspects, such as the sex-ratio, the birth weight and the stillbirth rate in both singletons and multiples. He continued to work extensively in the area till his last days, and in fact he did not see some of his last publications in print.
Aldur was also very active in the international organization of twin research. He took part in the First International Congress on Twin Studies that was held in Rome in 1974; and when the organizers, Luigi Gedda and Paolo Parisi, of the Mendel Institute, proposed at the Congress Closing to establish an international society, Aldur served in the working group that formulated the detailed steps to be taken to that effect.
He was then a founding fellow of ISTS –– the International Society for Twin Studies –– and one of its most active members for several years. He supported the efforts of the Rome office to set up and develop the Society, organize its various congresses, promote the journal (Acta Geneticae Medicae et Gemellologiae –– AGMG/Twin Research), of which he was also a Board member, and in various other activities. He organized the Fifth Congress in Amsterdam (Grand Hotel Krasnopolsky, September 15–19, 1986), following which he was elected ISTS President for the term, 1987–1989 –– the fifth, after Luigi Gedda (1974–1977), Gordon Allen (1978–1980), Ian MacGillivray (1981–1983), and Walter Nance (1984–1986). He was assisted in the organization by several of his associates at the Institute of Human Genetics, and by Jacobus F. Orlebeke, Head of the Department of Psychology at the Free University, where twin research was to be increasingly developed in later years by Dorret Boomsma and others.
After leaving to go to Finland for his medical studies, he never came back to settle in the Åland Islands, but visited them regularly as a scientist. His research groups went to the most isolated island, Kökar, where almost the whole population was investigated and the different hereditary diseases were studied. The surveys involved both the affected subjects and their relatives, identified by intensive genealogical investigations. Aldur thus had the opportunity to meet many people, and when he talked about these studies, one got the impression that he knew the whole Åland population. This was obviously not possible, there being about 25,000–30,000 inhabitants, but still many of them knew him well. His patients were very cooperative and felt privileged that their doctor was one of them, and because the local press was always very interested in his scientific work on the islands, he was well known also by those he had never met.
Aldur was a highly dependent person, very cooperative, always simple and modest, free of any form of conceit. We both had the privilege to know him personally and share with him part of our professional life and scientific interests, and we mourn his loss. He was a great colleague and scientist, a good friend, and above all, a most gentle nature.
He will be greatly missed.
