1946
Dr. Klein is born in New York City, New York to Hyman David and Ruth Harriet Klein.
1967
Dr. Klein receives a Bachelor of Arts from Columbia University.
1970
Dr. Klein studies postgraduate courses at Cambridge University.
1971
Dr. Klein receives a Doctor of Medicine from the Albert Einstein College of Medicine.
1973
Dr. Klein marries Joann Pamela Schulz.
1974
Dr. Klein finishes pediatrics residency training at Stanford University.
1974
Dr. Klein joins the U.S. Navy Medical Corps, serving as Lieutenant Commander.
1978
Dr. Klein completes a postdoctoral Fellowship in pediatric nutrition at Johns Hopkins Medical School and the Nutrition Research Institute in Lima, Peru.
1979
Dr. Klein receives the National Research Service Award.
1980
Dr. Klein receives a Master of Public Health from the University of California, Los Angeles and completes a Fellowship in pediatric gastroenterology.
1980
Dr. Klein is named Clinical Associate Physician by the National Institutes of Health and Adjunct Professor of pediatrics at the University of California, Los Angeles.
1982
Dr. Klein becomes an Assistant Professor of pediatrics and Adjunct Professor of nutrition at Tulane University, and the first fully qualified pediatric gastroenterologist in the state of Louisiana.
1990
Dr. Klein is certified in pediatrics, gastroenterology and nutrition through the American Board of Pediatrics.
1995
Dr. Klein becomes a Professor of pediatrics and Adjunct Professor of nutrition at the University of Texas Medical Branch in Galveston, Texas.
2009
Dr. Klein becomes a professor of pediatrics and director of pediatrics nutrition at the University of Kentucky College of Medicine and Kentucky Pediatrics Research Institute.
2010
Dr. Klein becomes a clinical professor of orthopedic surgery at the University of Texas Medical Branch. He also joins the science staff of Shriners Burns Hospital.
2018
Dr. Klein becomes senior scientist and Adjunct Professor of the orthopedic surgery at the University of Texas Medical Branch.