Molecular and Human Genetics
Baylor College of Medicine
Houston, TX, US
Graduate Program in Cancer & Cell Biology
Baylor College of Medicine
Graduate Program in Integrative Molecular and Biomedical Sciences
Baylor College of Medicine
The Cullen Foundation Professorship in Molecular Genetics
Baylor College of Medicine
Houston, Texas, United States
Dan L Duncan Comprehensive Cancer Center
Baylor College of Medicine
Houston, Texas, United States


PhD from Massachusetts Institute Of Technology
Post-Doctoral Fellowship at National Institutes Of Health
Post-Doctoral Fellowship at Baylor College Of Medicine
BA from University Of Virginia
Biology, Chemistry

Honors & Awards

Editor-in-chief, American Journal of Human Genetics
Barbara Bowman Distinguished Texas Geneticist Award
Secretary, American Society of Human Genetics
Cullen Foundation Chair in Molecular and Human Genetics
National Institute of Child Health and Human Development (NICHD) - Member, Mental Retardation Review Committee
Huntington Disease Society of America - Leadership Award
National Fragile-X Foundation - William Rosen Award

Professional Interests

  • Human genome and disease gene analysis
  • Fragile X syndrome
  • Incontinentia pigmenti
  • Complex genetics

Professional Statement

One of the most exciting recent developments in human genetics has been the identification of unstable trinucleotide repeats involved in high frequency mutations leading to more than one dozen genetic disorders, including myotonic dystrophy and Huntington's disease. With collaborators, Dr. Nelson described the first of these unstable DNA sequences, a CGG trinucleotide repeat in the FMR1 gene and responsible for the fragile X site and mental retardation found in people with Fragile X syndrome. This is the most common form of inherited mental retardation, with a frequency of ~1/2000 males in the general population. The mechanism by which this mutation leads to disease is through loss of function of the FMR1 gene product due to diminished expression resulting from aberrant methylation of the gene. Recent evidence suggests that the gene product of FMR1 interacts with complexes of RNA and ribosomes, implying a role in regulation of translation. Efforts in the Nelson group are focused on dissecting this pathway and understanding the development of DNA instability at this locus. Two additional fragile sites are found in the vicinity of the FMR1 gene on the X chromosome. The Nelson laboratory described one of these at the molecular level (FRAXF) and has identified a second gene involved in mental retardation expressed from the FRAXE fragile site (FMR2). Efforts to understand the function of FMR2 are underway.

The group has recently identified the gene defect in the X-linked disorder Incontinentia Pigmenti. This mutation is lethal in males, and leads to a spectrum of effects in females. Mutations are found in an essential modulator of NF-kB activity (NEMO), and the role of loss of function for this protein in the disease is under investigation.

The Nelson group has been involved in numerous aspects of the Human Genome Project, with key input into the mapping and sequencing of the human X chromosome, and participation in several other sequencing projects, from fly to Rhesus monkey. Dr. Nelson also has interest in the genetic contribution to common disorders such as cancer, and has investigated the potential role of common variants in genes involved in DNA repair in human disease.

Selected Publications