Jan M. N. Hoovers

Learn More
The DAZ genes are candidate fertility factors that lie within the human Y chromosome's AZFc region, whose deletion is a common cause of spermatogenic failure. The number of DAZ genes has been difficult to determine, in part because the nucleotide sequences of the DAZ genes are nearly identical. Here, fluorescence in situ hybridization and characterization(More)
To improve DNA resolution of fluorescence in situ hybridization we have adapted a nuclear extraction technique, resulting in highly extended DNA loops arranged around the nuclear matrix in a halo-like structure. In situ hybridization signals from alphoid and cosmid DNAs appear as beads-on-a-string, which, according to preliminary experiments, results from(More)
The chance of a male with severe oligozoospermia or azoospermia achieving a pregnancy has undergone a revolutionary increase with the introduction of the intracytoplasmic sperm injection technique (ICSI). However, since ICSI circumvents part of the natural sperm selection mechanisms, the possible transmission of genetic defects to the offspring is a major(More)
Beckwith-Wiedemann syndrome (BWS) involves fetal overgrowth and predisposition to a wide variety of embryonal tumors of childhood. We have previously found that BWS is genetically linked to 11p15 and that this same band shows loss of heterozygosity in the types of tumors to which children with BWS are susceptible. However, 11p15 contains > 20 megabases, and(More)
Mitochondrial trifunctional protein (MTP) is a recently identified enzyme involved in mitochondrial beta-oxidation, harboring long-chain enoyl-CoA hydratase, long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) and long-chain 3-ketothiolase activity. A deficiency of this protein is associated with impaired oxidation of long-chain fatty acids which can lead to(More)
AIMS Chromosomal gains and losses were surveyed by comparative genomic hybridisation (CGH) in a series of colorectal adenomas and carcinomas, in search of high risk genomic changes involved in colorectal carcinogenesis. METHODS Nine colorectal adenomas and 14 carcinomas were analysed by CGH, and DNA ploidy was assessed with both flow and image cytometry.(More)
OBJECTIVE The aim of this study was to determine if there is a significant difference in the risk of developing Wilms tumour between patients with submicroscopic and those with visible deletions of the WT1 tumour suppressor gene. METHODS To determine which subjects had WT1 deletions, high-resolution chromosomal deletion analysis of the 11p13 region was(More)
We have identified Celsr1, a gene that encodes a developmentally regulated vertebrate seven-pass transmembrane protein. The extracellular domain of Celsr1 contains two regions each with homology to distinct classes of well-characterized motifs found in the extra-cellular domains of many cell surface molecules. The most N-terminal region contains a block of(More)
A prospective assessment following a step-wise protocol in 281 patients with unexplained cognitive delay was used to assess diagnostic possibilities. Diagnostic procedures were complex and required a multidisciplinary approach. One third of diagnoses was established based on clinical history and physical exam only; for another third, clinical history and(More)
OBJECTIVE(S) To determine the copy number and identity of the DAZ genes on the Y chromosomes of infertile patients. DESIGN Prospective study. SETTING University medical center. PATIENT(S) One hundred and thirty-nine patients with male factor infertility. INTERVENTION(S) The separate genes were detected by polymerase chain reaction (PCR) digestion(More)