Ignatia B. Van den Veyver, M.D.
Vice Chair of Research
Baylor College of Medicine
Obstetrics & Gynecology
One Baylor Plaza
MS: BCM 610
Houston, TX 77030
Complete Hydatidiform Moles (CHM)
Our first project involves the study complete hydatidiform moles (CHM), an abnormal development of human pregnancy with a hyperplastic placenta and no fetus. Most sporadic CHM are diploid androgenetic: their entire genome is paternally inherited. This suggests that an imbalance between expression of paternally and maternally imprinted genes causes CHM. Rare recurrent HM have a normal biparentally inherited diploid genome (BiHM), but show a generalized defect of reprogramming of imprinting. The women who have the BiHM pregnancies have autosomal recessive mutations in NLRP7 on chromosome 19q13.4. We are focusing on characterizing the function of NLRP7 to understand how it can lead to disturbances in imprinting, BiHM, and other reproductive failure. For the second part of our CHM project, we perform methylation and expression screens on DNA and RNA from androgenetic CHMs to find new imprinted genes that have placenta-specific imprinting. These may be important for fetal nutrition and placental function in general.
Identification of Genes Mutated in Aicardi and Goltz syndrome
The second project focuses on the identification of the genes mutated in Aicardi syndrome (AIC) and Goltz syndrome or focal dermal hypoplasia (FDH), two severe X-linked disorders that only or primarily affect girls. Children with AIC have typical developmental defects of eyes and brain, severe seizures, and mental retardation. FDH patients have skin, eye, and skeletal defects. We have collected DNA samples from patients to search for the mutated gene by mutation analysis of candidate genes, and by comparative genomic hybridization on DNA microarrays. These studies led to our recent discovery that PORCN, encoding the human homolog of Drosophila porcupine which is essential for secretion of Wnt proteins, is the gene that is mutated in FDH. We are now embarking on the functional analysis of the consequence of mutations in PORCN using animal models.
Epigenetic Gene Regulation
In the third project, we are focusing on epigenetic gene regulation during development. We study in mice whether DNA methylation gene expression and long-term health and disease can be influenced by diets given at different stages of development. These studies are relevant to understanding the contribution of nutritional imbalance to the developmental origin of common adult-onset disorders.
I am also interested in Prenatal Diagnosis, Prenatal genetics, ultrasound, applications of new molecular diagnostic methods to prenatal diagnosis (such as array comparative genomic hybridization), and non-invasive prenatal diagnosis.