Welcome to this episode of Physician’s Weekly podcast. I am your host, Dr Rachel Giles, from Medicom Medical Publishers, in collaboration with Physician’s Weekly.
Today’s episode features two interviews, with an inDEPTH look at twins. In 1984, Hrubec and Robinette published what was arguably the first review of the role of twins in medical research. The authors acknowledged a growing distinction between two categories of twin studies: those aimed at assessing genetic contributions to disease and those aimed at assessing environmental contributions while controlling for genetic variation. “Classical twin models” compare phenotypic similarity within monozygotic or identical twin pairs to that within dizygotic or fraternal pairs to establish the proportion of variance in a given trait due to genetic variation within a population and the proportion due to environmental variation. ‘Twin differences’ or ‘discordant twin models', which focus on comparisons within monozygotic pairs control for maternal factors during pregnancy, gestational age, location and season of birth, postnatal familial factors, age, ethnicity, gender, and genetics, they are very useful in teasing out environmental factors. Later in this episode, we interview Dr. Karri Silventoinen (Dept Public Health, University Helsinki, Finland), an expert in twin studies, about his recent publication in Science Reports that identifies the significant effect of education on smoking prevention and cessation through discordant twin study involving more than 100,000 twin pairs.
But first I catch up with a doctor who was recently in world news for successfully separating craniopagus conjoined twins with fused brains, pediatric neurosurgeon Professor Owase Jeelani, from the Great Ormond Street Hospital for Children in London, the UK. Dr. Jeelani tells us how the surgery was “a really close call”, and how the team overcame an unexpected obstacle. In 2019, Dr. Jeelani co-founded Gemini Untwined, a global charity dedicated to supporting the research and treatment of craniopagus twins.
Hrubec Z, Robinette CD. The study of human twins in medical research. N Engl J Med. 1984 Feb 16;310(7):435-41.
McCallum S, BBC News 1 August 2022, Conjoined twins separated with the help of virtual reality. https://www.bbc.com/news/technology-62378452
Silventoinen K, et al. Smoking remains associated with education after controlling for social background and genetic factors in a study of 18 twin cohorts. Sci Rep. 2022 Jul 31;12(1):13148.