A cysteine protease inhibitor of plasmodium berghei is essential for exo-erythrocytic development

Plasmodium parasites express a potent inhibitor of cysteine proteases (ICP) throughout their life cycle. To analyze the role of ICP in different life cycle stages, we generated a stage-specific knockout of the Plasmodium berghei ICP (PbICP). Excision of the pbicb gene occurred in infective sporozoites and resulted in impaired sporozoite invasion of hepatocytes, despite residual PbICP protein being detectable in sporozoites. The vast majority of these parasites invading a cultured hepatocyte cell line did not develop to mature liver stages, but the few that successfully developed hepatic merozoites were able to initiate a blood stage infection in mice. These blood stage parasites, now completely lacking PbICP, exhibited an attenuated phenotype but were able to infect mosquitoes and develop to the oocyst stage. However, PbICP-negative sporozoites liberated from oocysts exhibited defective motility and invaded mosquito salivary glands in low numbers. They were also unable to invade hepatocytes, confirming that control of cysteine protease activity is of critical importance for sporozoites. Importantly, transfection of PbICP-knockout parasites with a pbicp-gfp construct fully reversed these defects. Taken together, in P. berghei this inhibitor of the ICP family is essential for sporozoite motility but also appears to play a role during parasite development in hepatocytes and erythrocytes.

The Social Life of African Trypanosomes

The unicellular parasite Trypanosoma brucei shuttles between its definitive host, the tsetse fly, and various mammals including humans. In the fly digestive tract, T. brucei must first migrate to the ectoperitrophic space, establish a persistent infection of the midgut and then migrate to the salivary glands before being transmitted to a new mammalian host. In 2010, it was shown that insect stages of the parasite (procyclic forms) exhibit social motility (SoMo) when cultured on a semi-solid surface, and it was postulated that this behaviour might reflect a migration step in the tsetse fly. Now, almost 5 years after the initial report, several new publications shed some light on the biological function of SoMo and provide insights into the underlying signalling pathways.

Iodine-129: Sample preparation, quality control and analyses of pre-nuclear materials and of natural waters from Lower Saxony, Germany

Sample preparation procedures for AMS measurements of 129I and 127I in environmental materials and some methodological aspects of quality assurance are discussed. Measurements from analyses of some pre-nuclear soil and thyroid gland samples and of a systematic investigation of natural waters in Lower Saxony, Germany, are described. Although the up-to-now lowest 129I/127I ratios in soils and thyroid glands were observed, they are still suspect to contamination since they are significantly higher than the pre-nuclear equilibrium ratio in the marine hydrosphere. A survey on all available 129I/127I isotopic ratios in precipitation shows a dramatic increase until the middle of the 1980s and a stabilization since 1987 at high isotopic ratios of about (3.6–8.3)×10−7. In surface waters, ratios of (57–380)×10−10 are measured while shallow ground waters show with ratios of (1.3–200)×10−10 significantly lower values with a much larger spread. The data for 129I in soils and in precipitation are used to estimate pre-nuclear and modern 129I deposition densities.

The Swiss Canine Cancer Registry: a retrospective study on the occurrence of tumours in dogs in Switzerland from 1955 to 2008

Diagnostic records are a key feature of any cancer epidemiology, prevention or control strategy for man and animals. Therefore, the information stored in human and animal cancer registries is essential for undertaking comparative epidemiological, pathogenic and therapeutic research. This study presents the Swiss Canine Cancer Registry, containing case data compiled between 1955 and 2008. The data consist of pathology diagnostic records issued by three veterinary diagnostic laboratories in Switzerland. The tumours were classified according to the guidelines of the International Classification of Oncology for Humans on the basis of tumour type, malignancy and body location. The dogs were classified according to breed, age, sex, neuter status and place of residence. The diagnostic data were correlated with data on the Swiss general dog population and the incidence of cancer in dogs was thus investigated. A total of 67,943 tumours were diagnosed in 121,963 dogs and 47.07% of these were malignant. The most common tumour location was the skin (37.05%), followed by mammary glands (23.55%) and soft tissue (13.66%). The most common tumour diagnoses were epithelial (38.45%), mesenchymal (35.10%) and lymphoid tumours (13.23%). The results are compared with data in other canine registries and similarities in tumour distribution and incidence are noted. It is hoped that this study will mark the beginning of continuous registration of dog tumours in Switzerland, which, in turn, will serve as a reference for research in the fields of animal and human oncology.

Short- and long-term efficacy and mechanism of action of tumescent suction curettage for axillary hyperhidrosis

BACKGROUND Axillary hyperhidrosis is a common and distressing problem interfering with the life of affected individuals. Currently, local surgery is the treatment of choice once conservative treatment has failed. OBJECTIVES To evaluate the clinical efficacy and safety of tumescent suction curettage (TSC) in treating axillary hyperhidrosis and to correlate it with histological markers. METHODS Thirty patients (17 females and 13 males, average age 29.9 years) underwent TSC. After tumescent anaesthesia, a suction cannula was inserted in the axilla on each side through two tiny incisions and subcutaneous tissue was removed by suction. We evaluated the clinical efficacy and complications, and in a subset of patients performed biopsies before surgery, as well as 1 month and 1 year after the operation. RESULTS In comparison with preoperative values, the sweat rate was diminished by 85% after 1 month, 71% after 6 months, 77% after 12 months and 61% after 24 months. The reduced efficacy with time was histologically correlated with an increase in the innervation, whereas the number of sweat glands continued to diminish. The majority of patients were satisfied with the operation but the satisfaction diminished with time. Patients with the highest preoperative sweat rates were the most satisfied after the intervention. CONCLUSION TSC is an effective and safe treatment for axillary hyperhidrosis. The long-term recurrence may be due to reinnervation.

DIRECT EFFECT OF MELATONIN UPON THE RELEASE OF GONADOTROPINS FROM THE SUPERFUSED PITUITARY GLAND OF THE MALE GOLDEN HAMSTER

The pineal gland is known to be light sensitive and to be involved in the seasonal reproduction of male golden hamster Mesocricetus auratus. In general, the pineal gland has been demonstrated to be inhibitory to the reproductive system of the male golden hamster. Melatonin is a pineal hormone which can mimic the action of the pineal gland upon the reproductive system. However, the actual site(s) of melatonin action in the hamster has not been demonstrated. In this study a direct effect of melatonin on the release of FSH and LH from superfused hamster pituitary glands was investigated.^ The superfused pituitary glands showed a stable in vitro basal release of FSH and LH for up to 10 hours. The superfused pituitaries demonstrated reproducible responses to repeated pulses of 10('-8) M LHRH, and a dose-dependent response to stimulation with different concentrations of LHRH.^ Melatonin inhibited the basal release of FSH and LH from superfused hamster pituitary glands. This effect of melatonin was specific and not a general indolamine or catecholamine effect.^ The superfused pituitaries had a diurnal differential responsiveness to physiological concentrations of melatonin with respect to FSH and LH release which were related to the light cycle used to maintain the experimental animals. A LD 14:10 photoperiod cycle was used with light on from 5 a.m. till 7 p.m.. With pituitary glands obtained at 8:30 a.m., the basal release of FSH exhibited an initial inhibition, a gradual rebound at approximately two hours after the beginning of melatonin superfusion, and a significant overshoot of FSH release after the cessation of infusion with melatonin (Morning Response). If the pituitary glands were obtained from hamsters which were sacrificed at 3:30 p.m., the release rate of FSH exhibited an inhibition during the entire period of melatonin infusion with a rebound effect appearing only after melatonin infusion was discontinued (Afternoon Response). There was no significant difference in the responsiveness of the pituitary gland to infusion with melatonin at either 8:30 a.m. or 3:30 p.m. with respect to LH release. Also, melatonin could not inhibit the gonadotropins response to continuous superfusion with 10('-9) M LHRH in pituitaries obtained at either 8:30 a.m. or 3:30 p.m., nor inhibit the stimulatory effect of pulsatile 10('-9) M LHRH. . . . (Author's abstract exceeds stipulated maximum length. Discontinued here with permission of author.) UMI^

MINERALOCORTICOID REGULATION OF ION CONDUCTIVE PATHWAYS OF THE CORTICAL COLLECTING DUCT

Mineralocorticoids (DOCA) are known to increase Na('+) absorption and K('+) secretion in the rabbit cortical collecting duct (CCD). However, the mechanism of regulation of the apical and basolateral cell membranes and tight junction ion conductive pathways (G('a), G('b), and G('tj), respectively) by mineralocorticoids are only partially understood. Using electrophysiological techniques and microelectrodes it was demonstrated that the apical cell membrane contained a dominant Ba('2+) sensitive K('+) conductive pathway, G(,K)('a), and an amiloride sensitive Na('+) conductive pathway, G(,Na)('a). The basolateral membrane contained a dominant Cl('-) conductive pathway, G(,Cl)('b), and a significant Ba('2+) sensitive K('+) conductive pathway, G(,K)('b). Upon elevating the mineralocorticoid levels of rabbits with intact adrenal glands it was found that V('te) was significantly increased after 1 day with a further increase after 13-16 days. These results indicated both primary and secondary effects of mineralocorticoid elevation. After 1 day of DOCA treatment, G(,Na)('a), I(,Na)('a) and I(,K)('a) increased by more than 2-fold and were maintained at high levels after 13-16 days of DOCA treatment. Secondary (chronic) effects of mineralocorticoids were evident after 4 days or more of DOCA treatment. These included a significant increase in G(,K)('a) from 4.0 to 10.2 mS.cm('-2) and a hyperpolarization of V('b) by -20 mV after 4 days of treatment. After 13-16 days of DOCA treatment V('b) remained hyperpolarized at -98.1 mV and G('tj) decreased from 5.6 to 4.2 mS.cm('-2). The hyperpolarization of V('b) was due to an increase in electrogenic Na('+) pump activity as the pump current, I(,act)('b), increased significantly from 35.7 to 195.2 (mu)A.cm('-2). Whereas net passive K('+) current across the basolateral membrane, I(,K)('b), was near zero in the control group of animals, i.e., K('+) near equilibrium, I(,K)('b) was approximately -40 (mu)A.cm('-2) in chronic DOCA treated animals. These results demonstrate that the initial effect of mineralocorticoid elevation is to increase G(,Na)('a). The ensuing depolarization of the apical membrane increases the driving force for K('+) exit into the lumen. Between 1 and 4 days of elevation, G(,K)('a) more than doubles in magnitude and at the same time the electrogenic activity of the Na('+) pump increases. This results in a hyperpolarization of V('b) which increases the driving force for K('+) uptake from the bath to the cell through a basolateral membrane conductive pathway. After 13-16 days G('tj) decreases thereby serving to maintain high electrochemical gradients across the epithelium. Therefore, the long term effects of mineralocorticoid elevation on the CCD appear to be adaptive mechanisms that serve to maintain high levels of K('+) secretion and Na('+) absorption. ^

The role of coactivator associated arginine methyltransferase 1 (CARM1) in nuclear receptor mediated transcription

Arginine methylation has been implicated in the regulation of gene expression. The coactivator-associated arginine methyltransferase 1 (CARMI/PRMT4) binds the p160 family of steroid receptor coactivators (SRCs). This association enhances transcriptional activation by nuclear receptors. Here, we generated and characterized CARM1 knockout mice. Embryos with a targeted disruption of CARM1 are 35% smaller in size than the wild-type littermates and die perinatally. We also generated Carm1-/- and Carm1+/+ mouse embryonic fibroblasts and tested gene expression in response to estrogen. Estrogenresponsive gene expression was aberrant in Carm1-/- fibroblasts and embryos, thus emphasizing the role of arginine methylation as a transcription activation tag. We subsequently studied the role of CARM1 in estrogen signaling in viva in the mammary gland. Conditional knockout of CARM1 in mammary gland and Carml-1-embryonic mammary anlagen transplant experiments did not show any defects in growth and development of the glands. To further dissect the role of CARM1 in estrogen receptor mediated transactivation, we performed cDNA microarray and serial analysis of gene expression on Carm1-/- and Carm1+/+ embryos treated with the estrogen analog, DES. Our results indicate global changes in estrogen regulated genes as well as genes involved in lipid homeostasis. Marker genes for Peroxisome Proliferator Activated Receptor γ (PPARγ) activity, adipsin and aP2, are downregulated in the Carm1-/- embryos. Furthermore, OCT frozen sections of 18.5dpc embryos, processed simultaneously for oil red O staining to look for neutral fat, reveals greatly reduced brown fat accumulation in the Carm1-/- embryos in contrast to wild-type and gain-of-function Carm1 transgenic (ubiquitous) embryo. We used a well-established 3T3-L1 preadipocyte cell line to knockdown CARM1 by short hairpin RNA. 3T3-L1 cells with CARM1 knockdown showed greatly reduced potential to differentiate into mature lipid accumulating adipocytes upon administration of adipogenic stimuli. Ligand-dependent activation of reporter genes by the PPARγ receptor showed that PPRE-luciferase reporter activity was enhanced in the presence of CARM1, additionally, luciferase activity was reduced to background levels when enzyme dead CARM1 (CARM1-VLD) was used. Thus, in this study, we have identified novel pathways that use CARM1 as coactivator and showed that CARM1 functions as a key component of PPARγ receptor mediated gene expression. ^

Identification and characterization of new genes involved in Drosophila heart development

Heart development is a crucial and conserved process that is related to the major type of human birth defects. Dorsal vessel, the Drosophila heart, has been regarded as an insightful system to identify new genes and study gene functions involved in heart development. Using heart-specific GFP transgenes, I did a genetic screen for cardiogenic genes on Drosophila chromosome II. Drosophila mutants that carry chromosome II deficiencies were tested for their phenotypes of heart development. Based on the screen results, chromosome regions containing genes required for heart development were identified. Fly strains with single gene mutations located within the defined deficiency regions were tested further. Seven genes have been identified to be involved in heart development. ^ The LIM homeodomain transcription factor gene tailup (tup) was further studied for its function in heart development. Based on this study, tup is expressed in cardioblasts and pericardial cells of the heart tube, as well as in associated lymph glands and alary muscles. In depth analysis of tup mutant phenotypes demonstrated tup is required for normal development of both heart and lymph glands. Tup was shown to bind to two DNA recognition sequences in the dorsal vessel enhancer of the Hand bHLH transcription factor gene, with one site proven essential for the expression of Hand in lymph glands, pericardial cells, and Svp/Doc cardioblasts. Together, these studies demonstrate that Tup is a critical new transcription factor in dorsal vessel morphogenesis and lymph gland formation, and strongly suggest Tup is a direct regulator of the expression of Hand in these developmental processes. ^

Ser88 phosphorylation regulates dynein light chain 1 (DLC1) function in the mouse mammary gland

Dynein light chain 1 (DLC1) is a highly conserved and ubiquitously expressed protein which might have critical cellular function as total loss of DLC1 caused Drosophila embryonic death. Despite many proteins and RNAs interaction with it identified, DLC1's function(s) and regulation are largely unknown. Recently, DLC1 was identified as a physiological substrate of P21-activate kinase 1(Pak1) kinase from a human mammary cDNA library in a yeast-2-hybridization screening assay. Studies in primary human tumors and cell culture implicated that DLC1 could promote mammary cancerous phenotypes, and more importantly, Ser88 phosphorylation of DLC1by Pak1 kinase was found to be essential for DLC1's tumorigenic activities. Based on the above tissue culture studies, we hypothesized that Ser88 phosphorylation regulates DLC1. ^ To test this hypothesis, we generated two transgenic mouse models: MMTV-DLC1 and MMTV-DLC1-S88A mice with mammary specific expression of the DLC1 and DLC1-S88A cDNAs. Both of the transgenic mice mammary glands showed rare tumor incidence which indicated DLC1 alone may not be sufficient for tumorigenesis in vivo. However, these mice showed a significant alteration of mammary development. Mammary glands from the MMTV-DLC1 mice had hyperbranching and alveolar hyperplasia, with elevated cell proliferation. Intriguingly, these phenotypes were not seen in the mammary glands from the MMTV-S88A mice. Furthermore, while MMTV-DLC1 glands were normal during involution, MMTV-S88A mice showed accelerated mammary involution with increase apoptosis and altered expression of involution-associated genes. Further analysis of the MMTV-S88A glands showed they had increased steady state level of Bim protein which might be responsible for the early involution. Finally, our in vitro data showed that Ser88 phosphorylation abolished DLC1 dimer and consequently might disturb its interaction with Bim and destabilize Bim. ^ Collectively, our findings provided in vivo evidence that Ser88 phosphorylation of DLC1 can regulate DLC1's function. In addition, Ser88 phosphorylation might be critical for DLC1 dimer-monomer transition. ^

Characterization of glucocorticoid receptor (NR3C1) gene polymorphisms and a family-based association study with hypertension

Hypertension is usually defined as having values of systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg. Hypertension is one of the main adverse effects of glucocorticoid on the cardiovascular system. Glucocorticoids are essential hormones, secreted from adrenal glands in circadian fashion. Glucocorticoid's effect on blood pressure is conveyed by the glucocorticoid receptor (NR3C1), an omnipresent nuclear transcription factor. Although polymorphisms in this gene have long been implicated to be a causal factor for cardiovascular diseases such as hypertension, no study has yet thoroughly interrogated the gene's polymorphisms for their effect on blood pressure levels. Therefore, I have first resequenced ∼30 kb of the gene, encompassing all exons, promoter regions, 5'/3' UTRs as well as at least 1.5 kb of the gene's flanking regions from 114 chromosome 5 monosomic cell lines, comprised of three major American ethnic groups—European American, African American and Mexican American. I observed 115 polymorphisms and 14 common molecularly phased haplotypes. A subset of markers was chosen for genotyping study populations of GENOA (Genetic Epidemiology Network of Atherosclerosis; 1022 non-Hispanic whites, 1228 African Americans and 954 Mexican Americans). Since these study populations include sibships, the family-based association test was performed on 4 blood pressure-related quantitative variables—pulse, systolic blood pressure, diastolic blood pressure and mean arterial pressure. Using these analyses, multiple correlated SNPs are significantly protective against high systolic blood pressure in non-Hispanic whites, which includes rsb198, a SNP formerly associated with beneficial body compositions. Haplotype association analysis also supports this finding and all p-values remained significant after permutation tests. I therefore conclude that multiple correlated SNPs on the gene may confer protection against high blood pressure in non-Hispanic whites. ^

S100A4 is a molecular mediator of endometrial carcinoma invasion

The molecular mechanisms of endometrail cancer invasion are poorly understood. S100A4, a member of the S100 Ca2+-binding protein family, was identified by oligonucleotide microarray qRT-PCR, and IHC, to be highly overexpressed in invasive endometrial carcinomas compared to non-invasive tumors. HEC-1A endometrial cancer cells transfected with S100A4 siRNA had undetectable S100A4 protein, decreased migration and invasion. The mechanism of S100A4 upregulation in endometrial cancer remains unclear. Methylation of the S100A4 gene was detected in benign endometrial glands and grade 1 tumors with no S100A4 expression. In contrast, grade 3 endometrioid tumors with high S100A4 expression showed no methylation of the gene. 5-Aza-2'-deoxycytidine, an inhibitor of DNA methyltransferase, induced the expression of S100A4 in the less invasive EC cell line, KLE, in which the S100A4 gene is hypermethylated and minimally expressed. S100A4 was induced during TGF-β1-triggered cell scattering in HEC-1A cells, in which S100A4 was demethylated. Transfection of HEC-1A cells with S100A4 siRNA significantly reduced the effect of TGF-β1 on basal migration and invasion. Our preliminary data suggested that this upregulation was mediated by the transcription factor Snail. One Snail binding consensus site was found in the region where DNA methylation was closely correlated with S100A4 gene expression. Chromatin immunoprecipitation assay confirmed the binding of Snail to this consensus site in HEC-1A cells. In SPEC2 endometrial cancer cells, loss of Snail leads to repressed S100A4 gene expression. Similar to S100A4, Snail was overexpressed in aggressive endometrial tumors. Our study suggested that the S100A4 gene was demethylated and further upregulated by the TGF-β1 and Snail pathway in invasive endometrial cancer. S100A4 could potentially serve as a good molecular marker for invasiveness and a target for therapeutic intervention for advanced endometrial cancer. ^

Breast cancer risk with aromatase inhibition and phytoestrogen-free diet

In this thesis a mouse model was used to examine the effect of pubertal estrogen inhibition and a phytoestrogen-free diet on the development of mammary glands. The study question was does treatment with aromatase inhibitor during puberty increase susceptibility to breast cancer among cohorts that consumed a diet free of phytoestrogens. The study design consisted of a cohort of mice treated with aromatase inhibitor, letrozole, during puberty and a vehicular group that was used as a control. Both groups were fed a diet free of phytoestrogens from the time of weaning until sacrifice during adulthood. The study aimed to assess mammary gland development in terms of breast cancer risk. The methods employed in this research included morphological and histological analysis of mammary glands, as well as estradiol, RNA and protein analysis. The main finding of the study was that mice exposed to aromatase inhibitor during puberty developed mammary glands with specific characteristics suggestive of vulnerability to oncogenesis such as increased lateral branching, increased number of glands, increase ductal hyperplasia, and diminished expression of TGFβ and p27 protein levels. The conclusions suggest that puberty is a critical period in which the mammary gland is susceptible to environmental threats that may result in deleterious epigenetic effects leading to an increased breast cancer risk in adulthood. This study has several public health implications; the most significant is that environmental threats during puberty may result in adverse mammary gland development and that phytoestrogen sources in the diet are necessary for normal maturation of the mammary glands.^

ROLE OF SOX9 IN UTERINE GLAND DEVELOPMENT AND DISEASE INITIATION

The female reproductive tract (FRT) develops midway through embryogenesis, and consists of oviducts, uterine horns, cervix and upper part of the vagina. The uterine horns are composed of an epithelial layer, luminal (LE) and glandular epithelium (GE), surrounded by a mesenchymal layer, the stroma and myometrium. Interestingly, in most mammals the GE forms after birth and it only becomes fully differentiated as the female reaches sexual maturity. Uterine glands (UG) are made up of GE and are present in all mammals. They secrete nutrients, cytokines and several other proteins, termed histotroph, that are necessary for embryo implantation and development. Experiments in ewes and mice have revealed that females who lack UGs are infertile mainly due to impaired implantation and early pregnancy loss, suggesting that UGs are essential for fertility. Fortunately for us, UGs develop after birth allowing us to peer into the genetic mechanism of tubulogenesis and branching morphogenesis; two processes that are disrupted in various adenocarcinomas (cancer derived from glands). We created 3D replicas of the epithelium lining the FRT using optical projection tomography and characterized UG development in mice using lineagetracing experiments. Our findings indicate that mouse UGs develop as simple tubular structures and later grow multiple secretory units that stem from the main duct. The main aim of this project was to study the role of SOX9 in the UGs. Preliminary studies revealed that Sox9 is mostly found in the nucleus of the GE. vii This observation led to the hypothesis that Sox9 plays a role in the formation and/or differentiation of the GE. To study the role of Sox9 in UGs differentiation, we conditionally knocked out and overexpressed Sox9 in both the LE and GE using the progesterone receptor (Pgr) promoter. Overexpressing Sox9 in the uterine epithelium, parts of the stroma, and myometrium led to formation of multiple cystic structures inside the endometrium. Histological analysis revealed that these structures appeared morphologically similar to structures present in histological tissue sections obtained from patients with endometrial polyps. We have accounted for the presence of simple and complex hyperplasia with atypia, metaplasia, thick-walled blood vessels, and stromal fibrosis; all “hallmarks” that indicate overexpressing Sox9 leads to development of a polyp-like morphology. Therefore, we can propose the use of Sox9-cOE mice to study development of endometrial cystic lesions and disease progression into hyperplastic lesions.

Attitudes About Predictive MEN1 Genetic Testing in Minors

Multiple Endocrine Neoplasia type 1 (MEN1) is a hereditary cancer syndrome characterized by tumors of the endocrine system. Tumors most commonly develop in the parathyroid glands, pituitary gland, and the gastro-entero pancreatic tract. MEN1 is a highly penetrant condition and age of onset is variable. Most patients are diagnosed in early adulthood; however, rare cases of MEN1 present in early childhood. Expert consensus opinion is that predictive genetic testing should be offered at age 5 years, however there are no evidence-based studies that clearly establish that predictive genetic testing at this age would be beneficial since most symptoms do not present until later in life. This study was designed to explore attitudes about the most appropriate age for predictive genetic testing from individuals at risk of having a child with MEN1. Participants who had an MEN1 mutation were invited to complete a survey and were asked to invite their spouses to participate as well. The survey included several validated measures designed to assess participants’ attitudes about predictive testing in minors. Fifty-eight affected participants and twenty-two spouses/partners completed the survey. Most participants felt that MEN1 genetic testing was appropriate in healthy minors. Younger age and increased knowledge of MEN1 genetics and inheritance predicted genetic testing at a younger age. Additionally, participants who saw more positive than negative general outcomes from genetic testing were more likely to favor genetic testing at younger ages. Overall, participants felt genetic testing should be offered at a younger age than most adult onset conditions and most felt the appropriate time for testing was when a child could understand and participate in the testing process. Psychological concerns seemed to be the primary focus of participants who favored later ages for genetic testing, while medical benefits were more commonly cited for younger age. This exploratory study has implications for counseling patients whose children are at risk of developing MEN1 and illustrates issues that are important to patients and their spouses when considering testing in children.