Dr. Victor A. McKusick, the Johns Hopkins University physician who is widely regarded as the father of medical genetics, died Tuesday at his home in Baltimore. He was 86 and died of complications from cancer.
McKusick was a pioneer in linking diseases to specific genes and began the first database of gene functions, a repository that now includes more than 18,000 human genes.
The two-week course in genetics taught by McKusick and his colleagues every summer in Bar Harbor, Maine, became the best-known and most respected course in the subject, bringing in more than 4,000 students, doctors and researchers from all over the country and introducing them to an entirely new way of addressing illnesses.
“Today we have lost a legend,” said Dr. Edward D. Miller, dean of the Johns Hopkins medical faculty and chief executive of Johns Hopkins Medicine. “His influence and legacy reach around the world.”
McKusick trained as a cardiologist and initially specialized in heart murmurs and other distinctive sounds. Using acoustic spectography technology developed by the Bell Telephone Laboratory, he was able to describe these sounds in more detail than had ever been possible.
His career path changed, however, when he encountered a patient who was much taller than the rest of his family and suffering from a dangerous weakening of the aorta and a detached retina.
McKusick recognized the symptoms as Marfan syndrome, a disorder of the connective tissue, and began studying the condition. By 1956, he had brought together all of the available information about it, creating the first definitive description of the disorder and leading him to wonder about its cause.
Studying families with the disorder who flocked to his office, he was eventually able to isolate the gene responsible for the disorder, identifying it in a 1991 paper as FBN-1. That discovery led to some potential new treatments for the disorder that are now being studied in clinical trials.
Intrigued by his early work with Marfan, and against the advice of many of his colleagues, McKusick turned to genetics full time, establishing one of the nation’s first departments of medical genetics at Johns Hopkins in 1957.
Early on, he recognized that inbred communities such as the Old Order Amish would be the best place to search for genes that cause recessive diseases -- those in which the defective gene must be inherited from both parents for the disease to manifest itself.
Using medical and genetic histories, he demonstrated that it was possible to identify the genes responsible for inherited physical abnormalities and disorders, such as achondroplasia and other forms of dwarfism. Acknowledging his work, the Little People of America, a support group for midgets and dwarfs, made the 6-foot-2 McKusick an honorary member.
In 1968, his team mapped the gene for a blood group on chromosome 1, the first time a gene had been identified on a non-sex chromosome. That feat had been much more difficult than finding a gene on a sex chromosome.
McKusick kept meticulous records of new gene discoveries and by 1966 had concluded that science needed a written record. That year, he published the first edition of his now-classic book “Mendelian Inheritance in Man,” which included 1,800 genes.
By the time the 12th and last printed version of the book appeared in 1998, it had grown to three volumes and about 12,000 genes. But the book became too unwieldy and is now published only online. The database was updated daily -- until recently, by McKusick himself.
In 1969, McKusick was one of the first to propose that the human genome, which comprises more than 3 billion units of DNA, should be sequenced. Although many colleagues scoffed at the idea because of its complexity, researchers were eventually able to realize his vision.
Today, entire genomes of humans and other species are sequenced routinely.
“I doubt that anyone would have conceived of the human genome project if he had not shined the light on the value of genetics in so many human conditions,” said Dr. Myron L. Weisfeldt, who succeeded McKusick as the William Osler Professor of Medicine at Johns Hopkins.
He was also among the first human geneticists to recognize the value of studying genetics in mice as a model for human disease, pioneering joint projects between researchers in both fields.
Victor Almon McKusick was born Oct. 21, 1921, on a dairy farm in rural Parkman, Maine, 20 minutes after his identical twin, Vincent. The two were the youngest of five children of their parents, teachers who emphasized the value of education.
Vincent McKusick became a lawyer and retired in 1992 as chief justice of the Maine Supreme Judicial Court.
In the summer of 1937, Victor McKusick suffered a severe streptococcus infection in his armpit and spent a week in the hospital in Maine and 10 weeks at Massachusetts General Hospital in Boston before he was finally treated with the antibiotic sulfanilamide, which had been introduced only a year earlier.
Before this experience, he had planned to enter the ministry, he later said, but “I decided I like what doctors did, [and] I decided I wanted to join them.”
In 1940, he enrolled in Tufts University because it had a medical school. But he had learned about Johns Hopkins from a Time magazine story in 1939 and, when that medical school offered admission to undergraduates in 1943 because of the wartime shortage of students, he left Tufts without completing his bachelor’s degree and enrolled at Johns Hopkins.
He never left, becoming the longest-tenured faculty member of the university.
Among his many awards were the 1997 Albert Lasker Award for Special Achievement in Medical Science, the 2001 National Medal of Science and the 2008 Japan Prize in Medical Genomics and Genetics.
McKusick is survived by his wife of 59 years, Ann, a retired associate professor of rheumatology at Johns Hopkins; a daughter, Carol Anne McKusick of Urbana, Ill.; two sons, Kenneth McKusick of Ruxton, Md., and the Rev. Victor McKusick of Herkimer, N.Y.; and his brother, Vincent.