On 4 August 2007, Marcy Carlson Speer, ever dignified, brave and graceful, died at the age of 47 after a long battle with breast cancer. Though her life was cut tragically short, she accomplished an enormous amount. Able to strike the delicate balance between her career and her family, Speer excelled as a scientist, wife and mother. She leaves behind a legacy of fruitful collaborations and important discoveries. More importantly, Marcy leaves to this world her beautiful, intelligent and kind daughters, Kira and Casey, to whom she gave the best of her character. For although she was dedicated to her craft, her devotion to her daughters and her husband Kevin exceeded all else.

Marcy Speer was born in Indianapolis and was raised in Indiana and Illinois. She graduated from Indiana University and earned a master's degree in genetic counseling from Sarah Lawrence College. After obtaining her PhD from Duke University, she did her postdoctoral work at Columbia University under Jurg Ott. She returned to Duke in 1994 for her first faculty appointment, and she made Duke her academic home until her death.

As a genetic epidemiologist, a certified genetic counselor and a board-certified medical geneticist, Speer had unusually broad training. This ultimately led her to become director of the Duke Center for Human Genetics and a professor of medicine and chief of the Division of Medical Genetics in the Department of Medicine at Duke University Medical Center. She also held joint appointments as a professor in both the Department of Biostatistics and Bioinformatics and the Department of Molecular Genetics and Microbiology at Duke. She was a valued and active member of the Duke faculty and the Duke Center for Human Genetics. She was a member of the Institutional Review Board (IRB) at Duke University, where her joint human genetics clinical and research experience proved invaluable, and she was a past member of the editorial board of the Journal of Genetic Counseling. She was also a current permanent member of the National Institutes of Health's Genetics of Health and Human Disease study section. Speer coauthored more than 100 peer-reviewed publications in her career. Often sought after as a collaborator and consultant, she contributed to numerous research projects at Duke and beyond. Her reputation knew no borders.

Speer's most important scientific contributions were in the genetic characterization of neurological disorders. Her laboratory cloned two muscular-dystrophy genes, leading to the availability of diagnostic testing for both. Respected and admired by her colleagues, Speer was an international leader in research to discover the genetic and environmental causes of childhood neurological birth defects, such as neural-tube defects and Chiari malformation. Recognized for her expertise in the field, Speer was a member of the medical advisory board of the American Syringomyelia Alliance Project, the chair of the American Syringomyelia Alliance Project Research Committee and a member of the Professional Advisory Committee of the Spina Bifida Association of America. Recently, her laboratory reported that specific combinations of polymorphisms in folate-related genes may increase risk for neural-tube defects, suggesting that routine periconceptional folate supplementation may need to be modified based on individual-specific profiles. Speer's recent research tackled one of the next great frontiers of genomic research, 'environmental genomics', which integrates the environmental component of disease into genomic approaches. Her work included an international component, and she was committed to reducing the incidence of neural-tube defects around the world.

Speer's contributions to the field of human genetics are impressive and are embodied in the numerous, prolific and talented students she mentored throughout her career. Her students and their education were her passion. Speer championed genetics education at Duke University by pouring considerable effort into the University Program in Genetics and Genomics, where she had served as director of admissions and director of graduate studies. Along with colleagues, she organized an annual course, Genetic Analysis of Complex Human Diseases, which continues and attracts students of human genetics research from around the world.

Marcy was first my student, then my colleague, but above all she will eternally remain my friend. We would often call each other late at night after spouses and children were asleep and talk for hours about the day's events and problems. She was there for me and my family during our own most painful moment. The love and support that she gave my husband, Jeff, my daughter, Danica, and me in the years that followed the death of our son I will carry in my heart, forever. We will always experience a loneliness left by her loss.

There are many reasons to remember Marcy and the contributions that she made to human genetics. Although her time was much too short, her impact on her chosen field was immense. However, I choose to remember Marcy as wife, mother and friend and for the role she played in the lives of all of us who knew and loved her; that is irreplaceable.