Evaluation of a clinical genetics service--a quality initiative.

Paper-based surveys are an effective means of evaluating the quality of a clinical service. As part of ongoing quality improvement initiatives within our Genetics Program, new patients were invited to participate in a paper-based survey. Issues related to the quality of counseling based on educational/informational aspects (e.g. whether testing was explained fully, testing options, the meaning of normal/abnormal testing), competency, respect and nondirectiveness of counseling in addition to clinical environment/setting were evaluated. Data related to demographics, discipline seen within the program and whether the patient was seen by a physician or genetic counselor were also captured. Five hundred questionnaires were distributed. One hundred and forty-seven questionnaires were returned, with a response rate of 29.4 %. The majority of patients seen were prenatal (pregnant) patients and comprised a heterogeneous group including those seen for advanced maternal age and abnormal maternal serum screening. Overall, 98.6 % of respondents felt their appointment in genetics was a positive experience. Issues related to confidentiality, pros and cons of testing, meaning of an abnormal test result and time allotted for decision making were significantly different in some disciplines between genetic counselor and geneticist. However, when controlling for referral indication, these differences lost significance with the exception of issues relating to confidentiality and perceived time allotted to organize thoughts and questions. This survey provided valuable information to allow for improvement in the quality of the provision of service.

Regulation of the lymphatic endothelial cell cycle by the PROX1 homeodomain protein.

The homeobox transcription factor PROX1 is essential for the development and maintenance of lymphatic vasculature. How PROX1 regulates lymphatic endothelial cell fate remains undefined. PROX1 has been shown to upregulate the expression of Cyclin E, which mediates the G(1) to S transition of the cell cycle. Here we demonstrate that PROX1 activates the mouse Cyclin E1 (Ccne1) promoter via two proximal E2F-binding sites. We have determined that the N-terminal region of PROX1 is sufficient to activate a 1-kb Ccne1 promoter, whereas the homeodomain is dispensable for activation. We have identified that the Prospero domain 1 (PD1) is required for the nuclear localization of PROX1. Our comparison of two DNA-binding-deficient constructs of PROX1 showed a cell-type-specific difference between these two proteins in both their localization and function. We demonstrated that siRNA-mediated knockdown of PROX1 in lymphatic endothelial cells decreases progression from G(1) to S phase of the cell cycle. We conclude that PROX1 activates the Ccne1 promoter independent of DNA binding, and our results illustrate a novel role for PROX1 in the regulation of lymphatic endothelial cell proliferation.

A large novel deletion in the APC promoter region causes gene silencing and leads to classical familial adenomatous polyposis in a Manitoba Mennonite kindred.

Familial adenomatous polyposis (FAP) is an autosomal dominant syndrome caused by the inheritance of germline mutations in the APC tumour suppressor gene. The vast majority of these are nonsense and frameshift mutations resulting in a truncated protein product and abnormal function. While APC promoter hypermethylation has been previously documented, promoter-specific deletion mutations have not been reported. In a large Canadian Mennonite polyposis kindred, we identified a large novel germline deletion in the APC promoter region by linkage analysis and MLPA. By RT-PCR and sequence analysis, this mutation was found to result in transcriptional silencing of the APC allele. A few genetic disorders have been characterized as over-represented in the Manitoba Mennonite population, however, the incidence of cancer has not been recognized as increased in this population as compared to other Manitoba ethnic groups. This study strengthens the likelihood that this novel APC promoter mutation is linked to this unique population as a founder mutation.

Characterization of Mesenchyme Homeobox 2 (MEOX2) transcription factor binding to RING finger protein 10.

The molecular mechanisms by which Mesenchyme Homeobox 2 (Meox2) regulates the proliferation, differentiation and migration of vascular smooth muscle cells and cardiomyocytes are not known. The discovery of MEOX2 binding proteins will aid in understanding how MEOX2 functions as a regulator of these key cellular processes. To identify MEOX2 binding proteins, a yeast two-hybrid screen of a human heart cDNA library was performed using a deleted MEOX2 bait protein that does not contain the histidine/glutamine rich region (MEOX2deltaHQ). Eleven putative interacting proteins were identified including RING finger protein 10 (RNF10). In vitro pull-down assays and co-immunoprecipitation studies in mammalian cells further supported the yeast data demonstrating RNF10 bound to MEOX2. The minimal RNF10 binding region of MEOX2 was determined to be a central region between the histidine/glutamine rich domain and the homeodomain (amino acids 101-185). The amino terminal region of RNF10, containing the RING finger domain, was not essential for the binding to MEOX2. Our results also demonstrated that MEOX2 activation of the p21WAF1 promoter was enhanced by RNF10 co-expression.