Swee Lay Thein

Swee Lay Thein (born 1952) is a Malaysian haematologist and physician-scientist who is Senior Investigator at the National Institutes of Health. She works on the pathophysiology of haemoglobin disorders including sickle cell disease and thalassemia.

Early life and education Thein was born in 1952 in Kuala Lumpur, Malaysia. She studied medicine in both Malaysia and the United Kingdom. She graduated from the University of Malaya in 1976. She specialised in hematology at the Royal Postgraduate Medical School and the Royal Free Hospital. She moved to Oxford, where she worked at the Medical Research Council (MRC) Molecular Hematology Unit in the Weatherall Institute of Molecular Medicine and the John Radcliffe Hospital. She held various positions at Oxford, including a MRC Clinical Training position, a Wellcome Trust senior fellowship and an honorary consultancy. She has studied the mechanisms responsible for the formation of foetal haemoglobin.

Thein demonstrated that HbF levels are mainly controlled by genetics, and that majority of the genetic variance is accounted for by factors outside the globin locus. The 6q QTL contains single-nucleotide polymorphisms distributed across three linkage disequilibrium blocks, in an intergenic region between MYB and HBS1L.

By delineating the genetics of foetal haemoglobin control in adults, she hopes to explain the trait variance in adults as well as identifying the loci and sequences of variants. She believes that by identifying the HbF QTLs she will be able to improve patient management through the development of novel therapies, more sophisticated genetic counselling and better predictions of disease severity. These therapies may include approaches to activate the BCL11A gene. She has been involved with the teaching of their programs on haematology.

Awards and honours 2001 – Elected Fellow of the Royal College of Pathologists 2001 – Elected Fellow of the Royal College of Physicians 2003 – Elected Fellow of the Academy of Medical Sciences 2019 – Elected Fellow of the Academy of Life Sciences for Chinese in the UK 2024 – Shaw Prize in Medicine 2025 – Elected Fellow of the Royal Society 2026 – Breakthrough Prize in Life Sciences 2026 – Warren Alpert Foundation Prize

Selected publications

Thein is an editor for Blood, Annals of Haematology, Hemoglobin, and the American Journal of Hematology.