List of presentations at Fifth International NTD conference
The Fifth International Workshop on NTDs (Sept. 24–27, 2007, Asilomar, CA) had 90 attendees from five continents and 15 countries, and included the participation of over 30 graduate and postdoctoral level students. The attendees' areas of interest included public health, epidemiology, developmental biology, molecular genetics, embryology, teratology, and dysmorphology. During the course of the workshop there were over 50 oral and 20 poster presentations.
The basic premise of this unique, small meeting was that individuals of different disciplines would come together to discuss their research, including negative findings and the results of preliminary and as yet unpublished studies on NTDs. At this year's meeting, we learned that ciliogenesis may be crucial to neural tube closure; when this process is abnormal, the planar cell polarity signaling cascade (important for normal tissue movement) is compromised, and proper neural tube closure may not occur. There were also several presentations on mouse models of NTDs, including examples of both folate-sensitive and folate-resistant models. For example, Professor Andrew Copp described his work with the curly tail mouse, which is known to be folate- resistant, but is responsive to myo-inositol (i.e., maternal supplementation with myo-inositol reduces the frequency of NTDs in homozygous curly tail mice, whereas supplementation with folate does not). Based on this research, a pilot clinical trial of myo-inositol supplementation for high risk human pregnancies is currently underway in the United Kingdom. In addition, a number of talks summarized current research on the genes involved in folate metabolism, including the folate binding protein gene, which is involved in the intracellular transport of folic acid, and MTHFR, the gene coding for the enzyme 5,10-methyltetrahydrofolate reductase.
Epidemiologic studies of folic acid fortification also figured prominently among the presentations. Investigators from South and Central America described efforts to establish fortification programs in their countries, whereas scientists from the Centers for Disease Control described efforts to determine the effectiveness of ongoing flour fortification programs. However, more than one presentation included results of population-based studies that did not show a significant decrease in the frequency of NTDs following folic acid fortification efforts, suggesting that efforts to increase folic acid fortification and supplementation may need to be stepped up.
Several presentations focused on maternal diabetes and/or obesity as risk factors for infant NTDs. A group of investigators from Nebraska described their finding that the expression of multiple genes, including several that are critical to proper neural tube closure, is de-regulated as a result of diabetes-induced hypoxic stress. Another group discussed the relationship between arsenic-induced NTDs in laboratory animals and hyperglycemia. They reported that, in the arsenic-exposed animals, provision of insulin reduces the frequency of the teratogen-induced NTDs, thus providing evidence that arsenic induces hyperglycemia.
A recurring debate at these workshops is whether encephaloceles should be considered neural tube closure defects. While there is compelling evidence to suggest that encephaloceles are caused by a different mechanism than neural tube nonclosure, at this last meeting, data from Western Australia were presented that showed folate fortification was associated with a reduction in the frequency of anencephaly and spina bifida, as well as a reduction in the frequency of encephaloceles. Another often mentioned topic of discussion at these workshops is how other forms of NTDs (e.g., lipomeningoceles, spinal dysraphism) relate to the more classically defined neural tube closure defects. Indeed, one of the talks was on classification and embryogenesis of defects of the secondary neural tube.
Additional presentations covered such diverse topics as the role of caffeine intake in causing NTDs, parallels between neurulation and otogenesis, possible genetic relationships between NTDs and cleft lip/palate, and a hypothesis that Noggin may contribute to a high rate of twinning. A list of all presentations and authors is provided at the end of this summary.
The greatest impact of this workshop, as demonstrated by comments made both at and after the meeting, was the opportunity for individuals from different disciplines, with the common interest of NTD research, to meet and interact. The workshop was characterized by a lively exchange of questions and ideas after virtually every presentation. A conference survey tool was given to attendees to complete, and on a scale of 1–5 (with 1 being the best), the conference scored on average 1.2. We received many positive statements at the conference and received many emails following the conference reiterating how well the attendees enjoyed it. This was true of first time attendees as well as those who have attended multiple workshops. These workshops are universally considered a great environment for graduate students and postdoctoral fellows to gain experience and exposure in a scientifically rigorous yet collegial environment.
Despite the air of camaraderie and the excitement present throughout the workshop, we never forgot that Marcy Speer was one of the original organizers of this meeting, and her presence was truly missed. We will never forget Marcy's stamp on this meeting, and to honor her memory, we instituted the Marcy C. Speer Memorial Award for the trainees deemed to have the best presentations. This year's honorees were Sandra de Castro (predoctoral award) and Patricia Ybot-Gonzalez (postdoctoral award). Both of these trainees work with Andy Copp and Nick Greene at UCL Institute of Child Health, London, UK.
