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Institute of Genetic Medicine: Past and Present

At Johns Hopkins, basic science and clinical practice in genetics have had a productive partnership for more than 60 years. Pioneering work in the 1950s by Victor McKusick in the Department of Medicine and Barton Childs in the Department of Pediatrics led to the creation of two divisions of genetics at Johns Hopkins and helped lay the foundation of the then-novel field.


Working in the Moore Clinic, McKusick and his colleagues Edmond Murphy, Samuel Boyer and Reed Pyeritz provided for the first time robust clinical descriptions of genetic diseases, such as mucopolysaccharidoses, Marfan syndrome, homocystinuria and many skeletal dysplasias.

To organize the ever-growing body of knowledge on disorders and make it accessible to physicians around the world, McKusick created Mendelian Inheritance in Man, currently known as Online Mendelian Inheritance in Man, or OMIM. Simultaneously, in the Division of Pediatric Genetics, substantial contributions were being made by Childs and Barbara Migeon on X chromosome inactivation, by Neil Holtzman on biochemical genetics, and by Michael Kabak and George Thomas on genetic screening tests for Tay-Sachs disease and on lysosomal disorders. Also at that time, Haig Kazazian, Stylianos Antonarakis and Gregg Semenza explored molecular causes of hemoglobinopathies, hemophilia and regulation of heomoglobin levels. 

In 1980, Migeon founded the Human Genetics Graduate Program, which continues to this day and has produced more than 300 Ph.D.s, nearly all of whom are prominent investigators.

In 1988, the two genetic divisions were joined physically and administratively to form the Center for Medical Genetics under the direction of Kazazian. The center was home to an active clinical genetics service and fostered continued research by leaders in the field, such as Samuel Boyer, Kirby Smith, Hal Dietz, Ethylin Jabs and David Valle.

At the same time, Dan Nathans, Ham Smith, Tom Kelly and others were conducting groundbreaking basic research within Johns Hopkins’ Department of Molecular Biology and Genetics, including the Nobel Prize-winning discovery of restriction enzymes. Collaborations between the medical geneticists and the basic scientists were key to many advances made at Johns Hopkins.

Formation of the Institute of Genetic Medicine

In 1999, the Johns Hopkins University School of Medicine formed the McKusick-Nathans Institute of Genetic Medicine (IGM). The name honored two early leaders in the field and emphasized translation of advances in genetics, molecular genetics and genomics to clinical medicine. 

Beginning in September 2000, Aravinda Chakravarti served as director of the IGM, where he expanded human genetics activities at Johns Hopkins in areas such as quantitative genetics, genomics and common complex traits.


Under the leadership of David Valle, the IGM has grown to a total of 45 primary faculty members. These members have “co-primary” appointments in 15 departments — 13 in the school of medicine, and one each in the Whiting School of Engineering and the Bloomberg School of Public Health. 

In December 2019, the IGM reached a new distinction with the formation of the McKusick-Nathans Institute of Genetic Medicine | Department of Genetic Medicine

Department of Genetic Medicine research includes finding the molecular bases of single-gene, or Mendelian, disorders; identifying the genes that influence complex traits, such as coronary artery disease; studying the genes and proteins that regulate whether genes are turned on or off; computational biology; molecular biology; developmental genetics; and proteomics. The Department of Genetic Medicine is also home to a number of research cores and services. These include the Center for Computational Biology, the Genetics Resources Core Facility (GRCF), the Center for Inherited Disease Research (CIDR), the Finzcenter Zebrafish Core Center, the DNA Diagnostic Lab (DDL), and the Center for Proteomics Discovery.

In 2015, the IGM and the Department of Pathology launched Johns Hopkins Genomics, which integrates CIDR, DDL, segments of GRCF, a new CLIA/CAP-approved clinical whole exome sequencing service and the Molecular Diagnostic Lab (MDL). The MDL provides a large fraction of the clinical molecular testing for the Johns Hopkins Kimmel Cancer Center.

Ada Hamosh is the Department of Genetic Medicine’s clinical director and oversees its clinical activities, including multiple outpatient clinics, a small but complicated inpatient service and an active consult service. Clinics include the Epigenetics and Chromatin Clinic, which treats patients with disorders of the machinery that packages DNA and regulates it via chemical “tags”; the Greenberg Center for Skeletal Dysplasias, which specializes in bone conditions, such as those that cause short stature; and the William S. Smilow Center for Marfan Syndrome Research.

Finally, the Department of Genetic Medicine is actively involved in medical student, graduate student, resident and postdoctoral education programs.