Genetic counselling resources in non-english languages: A scoping review

Objective

Genetic counselling is essential for individuals seeking genetic or genomic testing. Whereas innovative strategies for GC delivery are being explored to meet the growing demand on the clinical genetics workforce, it is essential to consider the unique needs of culturally and linguistically diverse populations.

Methods

We conducted a scoping review to examine the extent, range, and gaps in the body of non-English, patient-facing educational resources available for Limited English Proficient (LEP) patients accessing clinical genetics and genomics services.

Results

The literature search returned 246 unique resources, most available in several languages. Forty-six languages were represented, with Spanish, Russian, and French being the most common. Resources were in various formats and were of varying quality.

Conclusions

There is a lack of high-quality supplementary genetics education material available in languages other than English, which limits the quality-of-care that LEP families may receive compared to their English-speaking counterparts. Of equal concern is the difficulty in finding existing resources and in determining their quality.

Innovation

This research highlights the important need for genetics education material that is of good quality in languages other than English and the challenges associated with identifying this material. A central, curated repository, perhaps sponsored by a genetic counselling organization, would be of great benefit to help genetic counsellors meet the needs of their culturally and linguistically diverse patients.

A personalized genomic results e-booklet, co-designed and pilot-tested by families

Objective

To develop and evaluate a personalizable genomic results e-booklet that helps families understand their genomic testing results and navigate available resources.

Methods

The need for the Genomics Results e-Booklet was identified by families, after which this tool was developed by a team of clinical researchers and three parent-advisors. We customized the genomic results e-booklet for 50 families participating in a genomic sequencing research study. We conducted an assessment using a 19-question survey and semi-structured interviews to elicit feedback and iteratively improve the tool.

Results

25 users provided feedback via questionnaires and seven respondents were interviewed. Genomic Results e-Booklet recipients responded favorably: 96% of participants stated that it helped them remember information shared during their results appointment, 80% said it had or would help them communicate their results with other healthcare providers, 68% felt that it helped to identify and guide their next steps, and 72% anticipated that the e-booklet would have future utility.

Conclusion

The Genomic Results e-Booklet is a patient and family-oriented resource that complements post-test genetic counselling.

Innovation

Compared to traditional laboratory reports and clinical letters, the Genomics Results e-Booklet is patient-conceived and patient-centered, and allows clinicians to efficiently personalize content and prioritize patient understanding and support.

After genomic testing results: Parents' long-term views

Many parents are motivated to pursue genome-wide (exome or genome) sequencing to find a diagnosis for their child with a suspected but undiagnosed genetic condition. However, the impact of the genomic test extends beyond the provision of results and the so-called 'diagnostic odyssey'. Our goal was to quantify post-test decisional regret and characterize long-term, post-test experiences and unmet needs of the parents of children with suspected genetic diseases after they had received the results of genome-wide sequencing. Study participants were parents of children who underwent trio genome-wide sequencing as part of the CAUSES research study at Children's & Women's Health Centre of British Columbia. About half of the participants received a definite or likely genetic diagnosis after clinical interpretation of the genome-wide sequencing results. Parents who participated in the current study (n = 121) completed the Decisional Regret Scale four weeks after receiving results. A subset of these parents (n = 32) had semi-structured interviews a median of 7 months (range 3-20 months) after results disclosure and post-test genetic counseling. Most parents expressed either no regret or mild regret about having undergone genome-wide sequencing on both the Decisional Regret Scale and in the interviews. Parents whose children did not receive a genetic diagnosis were slightly more likely to have decisional regret on this quantitative scale. Analysis of transcribed interviews revealed the following major themes: (a) a lack of decisional conflict around having the testing; (b) a lack of decisional regret post-testing; (c) expressions of both relief and continued uncertainty around the meaning of a genetic diagnosis; (d) expression of initial disappointment and evolving interpretation surrounding a result yielding no genetic diagnosis; and (e) needing time to absorb the test results. Our results suggest that parents need time to absorb the testing results and that long-term post-test counseling, including acknowledging feelings of relief, loss, and disappointment, may help parents adapt to the genomic test results and assist families to anticipate and plan for the next steps in their child's medical trajectory, whether or not a diagnosis is found.

Utilization and uptake of clinical genetics services in high-income countries: A scoping review

Ongoing rapid growth in the need for genetic services has the potential to severely strain the capacity of the clinical genetics workforce to deliver this care. Unfortunately, assessments of the scale of this health policy challenge and potential solutions are hampered by the lack of a consolidated evidence base on the growth in genetic service utilization. To enable health policy research and strategic planning by health systems in this area, we conducted a scoping review of the literature on the utilization and uptake of clinical genetics services in high-income countries published between 2010 and 2018. One-hundred-and-ninety-five unique studies were included in the review. Most focused on cancer (85/195; 44%) and prenatal care (50/195; 26%), which are consistently the two areas with the greatest volume of genetic service utilization in both the United States and other high-income countries. Utilization and uptake rates varied considerably and were influenced by contextual factors including health system characteristics, provider knowledge, and patient preferences. Moreover, growth in genetic service utilization appears to be driven to a significant degree by technological advances and the integration of new tests into clinical care. Our review highlights both the policy challenge posed by the rapid growth in the utilization of genetic services and the variability in this trend across clinical indications and health systems.

The composition and capacity of the clinical genetics workforce in high-income countries: a scoping review

As genetics becomes increasingly integrated into all areas of health care and the use of complex genetic tests continues to grow, the clinical genetics workforce will likely face greatly increased demand for its services. To inform strategic planning by health-care systems to prepare to meet this future demand, we performed a scoping review of the genetics workforce in high-income countries, summarizing all available evidence on its composition and capacity published between 2010 and 2019. Five databases (MEDLINE, Embase, PAIS, CINAHL, and Web of Science) and gray literature sources were searched, resulting in 162 unique studies being included in the review. The evidence presented includes the composition and size of the workforce, the scope of practice for genetics and nongenetics specialists, the time required to perform genetics-related tasks, case loads of genetics providers, and opportunities to increase efficiency and capacity. Our results indicate that there is currently a shortage of genetics providers and that there is a lack of consensus about the appropriate boundaries between the scopes of practice for genetics and nongenetics providers. Moreover, the results point to strategies that may be used to increase productivity and efficiency, including alternative service delivery models, streamlining processes, and the automation of tasks.

Serial MRIs provide novel insight into natural history of optic pathway gliomas in patients with neurofibromatosis 1

BACKGROUND

Optic pathway gliomas (OPGs) are present in 20% of children with neurofibromatosis 1 (NF1) but are less frequently observed in adults. Our goal was to determine the natural history of OPGs in children and adults with NF1.

RESULTS

We analyzed the features of OPGs and other intracranial lesions on 1775 head MRI scans of 562 unselected adults and children with NF1 collected between 2003 and 2015. 52 (9.3%) of 562 patients in this study had an OPG diagnosed on their MRI. The median age at first scan with an OPG present was 12.7 years. Of the 52 OPG patients, the intraorbital optic nerves were affected in 29 patients (56%), the prechiasmatic optic nerves were affected in 32 patients (62%), the optic chiasm was affected in 17 patients (33%) and the optic radiations were affected in 19 patients (37%). 29 patients had two or more areas affected. One patient had a newly-appearing OPG, and 1 patient showed progression. The rate of progression over 5 years was 2.4% (95% CI: 0.4% to 16%). Four patients showed partial regression of their OPGs, but we observed no case of complete regression during this study. The rate of regression over 5 years was 8.9% (95% confidence intervals: 2.8% to 26%). We found the presence of UBOs and the presence of OPGs in individual patients to be highly associated (p = 0.0061).

CONCLUSION

OPGs are more common in older adults with NF1 than previously thought. The occurrences of unidentified bright objects (UBOs) and asymptomatic OPGs are associated with each other. This suggests the possibility that OPGs that remain asymptomatic may differ pathogenically from those that become symptomatic.

Non-optic glioma in adults and children with neurofibromatosis 1

BACKGROUND

Non-optic gliomas occur in 5% of children with NF1, but little is known about these tumours in adults. We aimed to investigate progression, spontaneous regression and the natural history of non-optic gliomas in adults and compare these findings to the results found in children.

RESULTS

One thousand seven hundred twenty-two brain MRI scans of 562 unselected individuals with NF1 were collected at the NF outpatient department of the University Hospital Hamburg-Eppendorf between 2003 and 2015. The number of scans per patient ranged from one to 12; patients were followed for a median of 3.7 years. We identified 24 patients (4.3%) with non-optic gliomas. Median age at first scan with glioma was 21.2 years, much higher than in previous publications. Only seven of the 24 non-optic glioma patients were symptomatic. Five of 24 patients had multiple non-optic gliomas. Four individuals developed a new tumour, and 4 cases showed progression. The risk of new tumour development was 0.19% (95% confidence interval 0.06% to 0.52%) per patient year of follow-up for patients over 10 years. The rate of progressing non-optic gliomas per patient year of follow-up in the first 5 years after tumour diagnosis was 4.7% (95% confidence interval 1.5% to 12%).

CONCLUSIONS

Non-optic gliomas are twice as common in an unselected cohort of NF1 patients as previously reported. This is likely due to increased frequency of diagnosis of asymptomatic tumours when routine MRIs are performed and a higher prevalence in older individuals.

Quantitative associations of scalp and body subcutaneous neurofibromas with internal plexiform tumors in neurofibromatosis 1

Internal plexiform neurofibromas are a major cause of adverse outcomes in patients with neurofibromatosis 1 (NF1). We investigated the relationship of the numbers of subcutaneous neurofibromas of the scalp or body to internal plexiform tumor volume in 120 NF1 patients who had undergone whole body magnetic resonance imaging (MRI). We identified internal plexiform neurofibromas in 55% of patients, subcutaneous neurofibromas of the body in 75%, and subcutaneous neurofibromas of the scalp in 45%. The number of subcutaneous neurofibromas of the body and scalp were associated with each other (Spearman's Rho = 0.36; P < 0.001). The presence of internal tumors was associated with the presence (odds ratio [OR] = 4.38, 95% confidence interval [CI] 2.04-9.86, P < 0.001) and number (OR = 1.06 per neurofibroma, 95% CI 1.02-1.13, P < 0.001) of subcutaneous neurofibromas of the scalp. The total internal tumor volume was associated with the number of subcutaneous neurofibromas of the body (OR = 1.00086 per neurofibroma, 1.000089-1.0016, P = 0.029) and of the scalp (OR = 1.056 per neurofibroma, 1.029-1.083, P < 0.0001). Numbers of subcutaneous neurofibromas of the scalp and body are associated with internal plexiform tumor burden in NF1. Recognition of these associations may improve clinical management by helping to identify patients who will benefit most from whole body MRI and more intense clinical surveillance.

The generalized bone phenotype in children with neurofibromatosis 1: a sibling matched case-control study

People with neurofibromatosis 1 (NF1) have low bone mineralization, but the natural history and pathogenesis are poorly understood. We performed a sibling-matched case-control study of bone mineral status, morphology, and metabolism. Eighteen children with NF1 without focal bony lesions were compared to unaffected siblings and local population controls. Bone mineral content at the lumbar spine and proximal femur (dual energy X-ray absorptiometry (DXA)) was lower in children with NF1; this difference persisted after adjusting for height and weight. Peripheral quantitative computed tomography (pQCT) of the distal tibia showed that trabecular density was more severely compromised than cortical. Peripheral QCT-derived estimates of bone strength and resistance to bending and stress were poorer among children with NF1 although there was no difference in fracture frequencies. There were no differences in the size or shape of bones after adjusting for height. Differences in markers of bone turnover between cases and controls were in the directions predicted by animal studies, but did not reach statistical significance. Average serum calcium concentration was higher (although within the normal range) in children with NF1; serum 25-OH vitamin D, and PTH levels did not differ significantly between cases and controls. Children with NF1 were less mature (assessed by pubertal stage) than unaffected siblings or population controls. Children with NF1 have a generalized difference of bone metabolism that predominantly affects trabecular bone. Effects of decreased neurofibromin on bone turnover, calcium homeostasis, and pubertal development may contribute to the differences in bone mineral content observed among people with NF1.

Genetics professionals' perspectives on reporting incidental findings from clinical genome-wide sequencing

Whole exome or whole genome analysis using massively parallel sequencing technologies will undoubtedly solve diagnostic dilemmas; however, incidental findings (IF) that may have medical and social implications will also be discovered. While there is consensus in the literature that analytically valid and medically actionable IF should be returned to patients if requested, there is debate regarding the return of other IF. There are currently no guidelines established for managing IF in the clinical context. We therefore distributed an online questionnaire to 496 geneticists and genetic counselors in Canada to explore this unresolved issue, and 210 professionals participated (response rate = 42%). The proportion of respondents who indicated that they would return IF to patients depended on the nature of the finding, ranging from 95% for information pertaining to a serious and treatable condition to 12% for information with only social implications (e.g., non-paternity). There was a lack of consensus around the disclosure of certain IF such as genetic carrier status, especially for pediatric patients. The most important considerations identified as impacting IF disclosure included condition-specific factors such as treatment availability, test accuracy, and evidence indicating pathogenicity. This is the first study to document the views of geneticists and genetic counselors in Canada towards the disclosure of IF, and represents a step towards evidence-based guidelines for clinical genome-wide sequencing investigations.

Valuing gene testing in children with possible neurofibromatosis 1

With the growing number of clinical guidelines recommending genetics tests in routine clinical care, the value of these tests should be evaluated. We examined the economic value of offering genetic testing to children with possible neurofibromatosis 1 (NF1) in British Columbia. Diagnosis of NF1 is usually made based on diagnostic clinical criteria, but molecular diagnostic testing, currently offered on a case-by-case basis in BC, now reliably diagnoses NF1 in 95% of cases. Children who present with some clinical features but whose findings are insufficient to meet the diagnostic criteria are labelled as having 'possible NF1'. Current guidelines call for these children to be followed as they have NF1, leading to annual ophthalmologic examinations and screening for complications; thus, there are increased costs to health care system. We created a model to account for these costs to the health care system, comparing the current protocol with one that would offer all children diagnosed with possible NF1 with genetic testing. Focusing on the incremental cost allowed us to determine that genetic testing provides good value, and patient interviews provided insight into the qualitative benefits of an earlier firm diagnosis. These findings may be helpful in guiding health policy decision-making.

MIA is a potential biomarker for tumour load in neurofibromatosis type 1

BACKGROUND

Neurofibromatosis type 1 (NF1) is a frequent genetic disease characterized by multiple benign tumours with increased risk for malignancy. There is currently no biomarker for tumour load in NF1 patients.

METHODS

In situ hybridization and quantitative real-time polymerase reaction were applied to investigate expression of cartilage-specific genes in mice bearing conditional inactivation of NF1 in the developing limbs. These mice do not develop tumours but recapitulate aspects of NF1 bone dysplasia, including deregulation of cartilage differentiation. It has been recently shown that NF1 tumours require for their growth the master regulator of cartilage differentiation SOX9. We thus hypothesized that some of the cartilage-specific genes deregulated in an Nf1Prx1 mouse model might prove to be relevant biomarkers of NF1 tumours. We tested this hypothesis by analyzing expression of the SOX9 target gene product melanoma-inhibitory activity/cd-rap (MIA) in tumour and serum samples of NF1 patients.

RESULTS

Increased expression of Mia was found in Nf1-deficient cartilage in mice. In humans, MIA was expressed in all NF1-related tumours and its serum levels were significantly higher in NF1 patients than in healthy controls. Among NF1 patients, MIA serum levels were significantly higher in those with plexiform neurofibromas and in those with large number of cutaneous (> 1,000) or subcutaneous (> 100) neurofibromas than in patients without such tumours. Most notably, MIA serum levels correlated significantly with internal tumour burden.

CONCLUSIONS

MIA is a potential serum biomarker of tumour load in NF1 patients which could be useful in following the disease course and monitoring the efficacy of therapies.

Skeletal abnormalities in neurofibromatosis type 1: approaches to therapeutic options

The skeleton is frequently affected in individuals with neurofibromatosis type 1, and some of these bone manifestations can result in significant morbidity. The natural history and pathogenesis of the skeletal abnormalities of this disorder are poorly understood and consequently therapeutic options for these manifestations are currently limited. The Children's Tumor Foundation convened an International Neurofibromatosis Type 1 Bone Abnormalities Consortium to address future directions for clinical trials in skeletal abnormalities associated with this disorder. This report reviews the clinical skeletal manifestations and available preclinical mouse models and summarizes key issues that present barriers to optimal clinical management of skeletal abnormalities in neurofibromatosis type 1. These concepts should help advance optimal clinical management of the skeletal abnormalities in this disease and address major difficulties encountered for the design of clinical trials.

Detection of pathogenic copy number variants in children with idiopathic intellectual disability using 500 K SNP array genomic hybridization

BACKGROUND

Array genomic hybridization is being used clinically to detect pathogenic copy number variants in children with intellectual disability and other birth defects. However, there is no agreement regarding the kind of array, the distribution of probes across the genome, or the resolution that is most appropriate for clinical use.

RESULTS

We performed 500 K Affymetrix GeneChip array genomic hybridization in 100 idiopathic intellectual disability trios, each comprised of a child with intellectual disability of unknown cause and both unaffected parents. We found pathogenic genomic imbalance in 16 of these 100 individuals with idiopathic intellectual disability. In comparison, we had found pathogenic genomic imbalance in 11 of 100 children with idiopathic intellectual disability in a previous cohort who had been studied by 100 K GeneChip array genomic hybridization. Among 54 intellectual disability trios selected from the previous cohort who were re-tested with 500 K GeneChip array genomic hybridization, we identified all 10 previously-detected pathogenic genomic alterations and at least one additional pathogenic copy number variant that had not been detected with 100 K GeneChip array genomic hybridization. Many benign copy number variants, including one that was de novo, were also detected with 500 K array genomic hybridization, but it was possible to distinguish the benign and pathogenic copy number variants with confidence in all but 3 (1.9%) of the 154 intellectual disability trios studied.

CONCLUSION

Affymetrix GeneChip 500 K array genomic hybridization detected pathogenic genomic imbalance in 10 of 10 patients with idiopathic developmental disability in whom 100 K GeneChip array genomic hybridization had found genomic imbalance, 1 of 44 patients in whom 100 K GeneChip array genomic hybridization had found no abnormality, and 16 of 100 patients who had not previously been tested. Effective clinical interpretation of these studies requires considerable skill and experience.

Assessment of algorithms for high throughput detection of genomic copy number variation in oligonucleotide microarray data

Background

Genomic deletions and duplications are important in the pathogenesis of diseases, such as cancer and mental retardation, and have recently been shown to occur frequently in unaffected individuals as polymorphisms. Affymetrix GeneChip whole genome sampling analysis (WGSA) combined with 100 K single nucleotide polymorphism (SNP) genotyping arrays is one of several microarray-based approaches that are now being used to detect such structural genomic changes. The popularity of this technology and its associated open source data format have resulted in the development of an increasing number of software packages for the analysis of copy number changes using these SNP arrays.

Results

We evaluated four publicly available software packages for high throughput copy number analysis using synthetic and empirical 100 K SNP array data sets, the latter obtained from 107 mental retardation (MR) patients and their unaffected parents and siblings. We evaluated the software with regards to overall suitability for high-throughput 100 K SNP array data analysis, as well as effectiveness of normalization, scaling with various reference sets and feature extraction, as well as true and false positive rates of genomic copy number variant (CNV) detection.

Conclusion

We observed considerable variation among the numbers and types of candidate CNVs detected by different analysis approaches, and found that multiple programs were needed to find all real aberrations in our test set. The frequency of false positive deletions was substantial, but could be greatly reduced by using the SNP genotype information to confirm loss of heterozygosity.

Oligonucleotide microarray analysis of genomic imbalance in children with mental retardation

The cause of mental retardation in one-third to one-half of all affected individuals is unknown. Microscopically detectable chromosomal abnormalities are the most frequently recognized cause, but gain or loss of chromosomal segments that are too small to be seen by conventional cytogenetic analysis has been found to be another important cause. Array-based methods offer a practical means of performing a high-resolution survey of the entire genome for submicroscopic copy-number variants. We studied 100 children with idiopathic mental retardation and normal results of standard chromosomal analysis, by use of whole-genome sampling analysis with Affymetrix GeneChip Human Mapping 100K arrays. We found de novo deletions as small as 178 kb in eight cases, de novo duplications as small as 1.1 Mb in two cases, and unsuspected mosaic trisomy 9 in another case. This technology can detect at least twice as many potentially pathogenic de novo copy-number variants as conventional cytogenetic analysis can in people with mental retardation.

Experimental findings on the nasal tract resonator in singing

SUMMARY

Many professional operatic singers sing the vowel /a/ with a velopharyngeal opening.(1) Here resonatory effects of such an opening are analyzed. On the basis of CAT scan imaging of a baritone singer's vocal tract and nasal cavity system, including the maxillary sinuses, acoustic epoxy models were constructed, in which velopharyngeal openings were modeled by different tubes. The sound transfer characteristics of this model were determined by means of sine-tone sweep measurements. In an idealized (iron tube) model, the VPO introduced a zero in the transfer function at the frequency of the nasal resonance. In the epoxy models, however, the resonances of the nasal system, and hence the zero, were heavily damped, particularly when the maxillary sinuses were included in the nasal system. A velopharyngeal opening was found to attenuate the first formant in /a/, such that the relative level of the singer's formant increased. A similar effect was observed in a modified epoxy model shaped to approximate the vocal tract of an /u/ and an /i/, although it also showed a substantial widening of the first formant bandwidth. Varying the size of the velopharyngeal opening affected the transfer function only slightly. It seems likely that singers can enhance higher spectrum partials by a careful tuning of a velopharyngeal opening.

Bowel function following insertion of self-expanding metallic stents for palliation of colorectal cancer

OBJECTIVE

Self-expanding metallic stents (SEMS) are an important addition to the treatment of large bowel obstruction. The aim of this study was firstly to assess bowel function following SEMS placement and secondly to identify any potential factors which might aid in the prediction of technical failure of stent insertion.

METHODS

A review of all patients undergoing attempted SEMS placement for palliation of malignant left-sided colorectal obstruction over a four-year period (1st May 2000-30th April 2004) was performed.

RESULTS

Twenty-one patients (12 male) with a median age of 76 years (range 48-92 years) were included, 11 with metastatic disease and 10 severe comorbidity. SEMS insertion was technically successful in 16 (76%) of 21 cases. Contrast successfully passed through the obstructing lesion in all 16 cases where SEMS placement was technically successful. It only passed through 1 of 5 cases where stenting was not possible (P = 0.0008, Fisher's Exact test). Complications included colonic perforation (1 case), stent migration (1 case) and tumour ingrowth requiring a second stent (1 case). Median survival after SEMS was 12 months (range 1-30 months), and 9 patients died during follow-up. Median bowel frequency following SEMS was 3.5 times per day (range 1-7). Eight patients always passed a liquid stool, 3 others regularly required laxatives and one further patient with poor function after stenting requested a defunctioning stoma.

CONCLUSION

Failure of contrast to pass through the obstructing lesion may predict those cases where stenting will not be technically possible. Median survival following SEMS insertion is encouraging in this series, but bowel function is often poor. Expected bowel function should be discussed fully when consenting patients for a SEMS, particularly those with metastatic disease who are otherwise fit for resectional surgery.

Subcutaneous neurofibromas are associated with mortality in neurofibromatosis 1: a cohort study of 703 patients

Neurofibromatosis 1 (NF1) is a common genetic disorder with an autosomal dominant mode of inheritance, an increased morbidity and mortality, and a shorter lifespan. Although the disease is fully penetrant by the age of 8, the variability in symptoms and complications is high, even among members of the same family. The aim of this study was to identify easily recognizable clinical features that may be associated with mortality in a cohort of patients affected with NF1. We used prospectively collected data from the Neurofibromatosis Institute Database (NFID) and included in our analysis 703 patients who fulfilled the NIH diagnostic criteria for NF1. Clinical, especially dermatological features were tested as potential factors associated with mortality. Among the patients, 405 (57.6%) were children and 298 (42.4%) were adults. The mean follow-up was 2.4 years (median = 0.98, range: 0-15.3 years). Forty patients died during follow-up, mostly due to tumor development such as sarcoma (n = 18). In the adult population, subcutaneous neurofibromas (odds ratio [OR] = 3.6, 95% confidence interval (CI): [1.2-11.3], P = 0.02) and male gender (OR = 5.6, [1.5-20.9], P = 0.004) were independent predictors of mortality after adjustment for age. Among children, the presence of facial plexiform neurofibromas and pruritus were significantly associated with mortality in univariate analysis. Our study describes independent risk factors of mortality in a large cohort of adult and pediatric patients. Close follow-up should be obtained for patients presenting with subcutaneous neurofibromas.

Utility and limitations of genetic disease databases in clinical genetics research: A neurofibromatosis 1 database example

Databases that collect clinical information on patients with particular genetic diseases can be used to investigate the clinical history of a disorder, its genetics, and genotype-phenotype correlations. A database can also serve as a valuable source of patients for studies of disease pathogenesis, variability, or treatment. We review the strengths and limitations of genetic disease databases in the context of our experience with the National Neurofibromatosis Foundation International Database (NNFFID). Genetic disease databases have been developed by individual investigators, scientific consortia, patient support organizations, and commercial enterprises. Databases vary from simple lists of affected individuals to comprehensive collections of detailed clinical and genetic information. Data may be obtained from people who volunteer to be included, systematic assessments of patients seen at participating medical centers, or population-based registries. Access to information may be highly restricted or widely available. These variables all affect the possible uses and usefulness of the data for research. Technical aspects of data entry, organization, storage, and retrieval, as well as issues related to data quality, confidentiality, and security, help determine how well a system actually functions. We discuss examples of research that have been accomplished with genetic disease databases and make recommendations regarding the organization and operation of these resources.

Genital tract and plasma human immunodeficiency virus viral load throughout the menstrual cycle in women who are infected with ovulatory human immunodeficiency virus

OBJECTIVE

The purpose of this study was to determine the vaginal, cervical, and plasma viral load through the menstrual cycle in women who are positive for human immunodeficiency virus.

STUDY DESIGN

A prospective cohort study was performed on 14 women with ovulatory menstrual cycles who have human immunodeficiency virus. Duplicate cervical and vaginal viral load samples (n = 301) were taken at four stages (menstrual, follicular, periovulatory, and luteal) of two consecutive cycles.

RESULTS

Participant characteristics were mean age of 32.7 years, median human immunodeficiency virus helper cell count value of 355, and median plasma viral load of 24,000 copies/mL. Through the menstrual cycle, there was no statistically significant difference in plasma viral load, but there was a significant decrease in genital tract viral load at the periovulatory phase (vagina, P =.018; cervix, P =.007). Vaginal and cervical viral load were correlated (r = 0.582, P <.001).

CONCLUSION

Although the plasma viral load remained constant throughout the menstrual cycle, the genital viral load decreased at the periovulatory phase. These results suggest that local factors may affect the genital viral load compartment independent of plasma viral load.

Vertebral scalloping in neurofibromatosis type 1: a quantitative approach

OBJECTIVE

To investigate quantitative differences in vertebral scalloping between children who have scoliosis with and without neurofibromatosis type 1 (NF1).

DESIGN

A retrospective study.

SETTING

A university-affiliated children's hospital.

PATIENTS

Twenty-seven children with scoliosis, 13 of whom had NF1 and 14 of whom did not.

METHOD

Existing radiographs of the lumbar vertebrae were used to measure and compare the degree of vertebral scalloping.

MAIN OUTCOME MEASURES

The distribution of posterior scalloping ratios in the 2 groups and the most extreme ratio in each subject in each group were compared.

RESULTS

Scalloping ratios from the children with NF1 were not normally distributed: 31% had ratios greater than 1.20. Scalloping ratios from the non-NF1 children were normally distributed, with a mean ratio (and standard deviation) of 1.13 (0.03). The distribution between the 2 groups was significantly different (p < 0.05).

CONCLUSIONS

In children who have scoliosis but no NF1 there was a range of mild scalloping whereas those with NF1 has severe scalloping. Further studies are needed to determine the possible role of vertebral scalloping in scoliosis severity and progression in children who have NF1.

Paternal preconceptional irradiation, population mixing and solid tumors in the children of radiation workers (England)

OBJECTIVE

To investigate whether there was an increased incidence of solid tumors among offspring of male radiation workers at the Sellafield nuclear installation in Cumbria, northwest England and whether paternal preconceptional irradiation was associated with the risk of solid tumors.

METHODS

A cohort study of 266,710 live births in Cumbria, 1950-1991, followed up to age 25 years on the end of 1991.

RESULTS

Children of radiation workers had a non-significantly increased risk of solid tumors (RR= 1.5, 95% CI: 0.9-2.4, p = 0.09), determined largely by an increased risk of cancers excluding leukemias, lymphomas, brain, spinal and gender-specific tumors (RR= 1.9, 95% CI: 1.0-3.3, p = 0.05), which was partly explained by differing patterns of parental migration (adjusted RR= 1.7, 95% Cl: 0.8-3.2, p = 0.50). Within children of radiation workers there was no evidence of an increased risk with increasing paternal preconception dose of external radiation (hazard ratio per 100 mSv for all solid tumors=0.6, 95% CI: 0.1-1.8, p = 0.52).

CONCLUSIONS

Any observed excess of solid tumors in children of radiation workers may be partly explained by population mixing. Fathers' occupational exposure to radiation before conception was not found to be risk factor for solid tumors in their children.

Dynamic complex wave-front modulation with an analog spatial light modulator

A method of producing an arbitrary complex field modulation by use of two pixels of an analog ferroelectric spatial light modulator (SLM) is demonstrated. The method uses the gray-scale modulation capabilities of a SLM to spatially encode the complex data on two pixels. A spatial filter is used to remove the carrier signal. This technique gives fast gray-level amplitude and phase modulation.

Experimental implementation of a Wiener filter in a hybrid digital--optical correlator

We present the implementation of a clutter-tolerant filter in a hybrid correlator system. Wiener filters were mapped with a complex encoding technique onto a smectic A(*) liquid-crystal spatial light modulator (SLM). The technique overcomes the problem of representing high-dynamic-range data on SLM's that have limited modulation capabilities. It also provides a compact image recognition system that is robust enough for many real-world applications. Experimental results are presented.

Growth in North American white children with neurofibromatosis 1 (NF1)

OBJECTIVE

To analyse the distributions of and generate growth charts for stature and occipitofrontal circumference (OFC) in neurofibromatosis 1 (NF1) patients.

DESIGN

Cross sectional database survey.

SETTING

The National Neurofibromatosis Foundation International Database (NFDB) includes clinical information on NF1 patients from 14 participating centres in North America.

SUBJECTS

A total of 569 white, North American, NF1 patients, 55% female and 45% male.

MAIN OUTCOME MEASURES

Stature and OFC measurements of NF1 patients were compared to age and sex matched population norms using z score standardisation and centile curves.

RESULTS

The distributions of stature and OFC are shifted and unimodal among NF1 patients; 13% of patients have short stature (>/=2 standard deviations below the population mean) and 24% have macrocephaly (OFC >/=2 standard deviations above the population mean).

CONCLUSIONS

Alterations of stature and OFC are not limited to NF1 patients with frank short stature or macrocephaly.

Associations of clinical features in neurofibromatosis 1 (NF1)

Neurofibromatosis 1 (NF1), an autosomal dominant disease, exhibits extreme clinical variability. This variability greatly increases the burden for affected families and impairs our ability to understand the pathogenesis of NF1. Recognition of heterogeneity within a disease may provide important pathogenic insights, therefore we tested clinical data from three large sets of NF1 patients for evidence that certain common features are more likely to occur in some NF1 patients than in others. Clinical information on 4,402 patients with NF1 was obtained from three independent databases. We examined associations between pairs of clinical features in individual affected probands. We also examined associations between the occurrence of individual features in affected relatives. Associations were summarized as odds ratios with 95% confidence intervals. We found associations between several pairs of features in affected probands: intertriginous freckling and Lisch nodules, discrete neurofibromas and plexiform neurofibromas, discrete neurofibromas and Lisch nodules, plexiform neurofibromas and scoliosis, learning disability or mental retardation and seizures. We also found associations between the occurrence of Lisch nodules, macrocephaly, short stature, and learning disability or mental retardation as individual features in parents and children with NF1. Our observations suggest that, contrary to established belief, some NF1 patients are more likely than others to develop particular manifestations of the disease. Genetic factors appear to determine the development of particular phenotypic features.

Chronic neuropathic pain in treated leprosy

The existence of chronic neuropathic pain in treated leprosy has received scant attention. We describe the clinical findings of 16 patients with multibacillary leprosy who had chronic stimulus-independent pain despite finishing their treatment. With confirmation, our results could be of importance in the establishment of "care after cure" programmes for patients with leprosy.

The relationship between perceived dysfunctional family-of-origin rules and intimacy in young adult dating relationships

This study examined the relationship between perceived dysfunctional family-of-origin rules and intimacy in single young adult dating relationships. A sample of 754 single, Caucasian-American young adults completed measures of perceived dysfunctional family-of-origin rules and emotional, intellectual, and sexual intimacy in dating relationships. When controlling for the effects of gender and age, results showed that perceived dysfunctional family-of-origin rules had a negative impact on the perceived expression and experience of these three kinds of intimacy in dating relationships. Implications for relationship therapy are discussed.

King Solomon's miners--starvation and bioaccumulation? An environmental archaeological investigation in Southern Jordan

Copper mining and smelting were important activities in various predesert wadis during the Iron Age, Nabatean, Roman, and Byzantine periods in southern Jordan and major spoil tips together with slag heaps remain as a legacy of such enterprises. Barley has grown in the area for a prolonged period and currently wild barley plants are affected by toxic cations, which reduce their yields. It is considered that such plants provide an adequate model to assess how similar plants would have performed, in terms of productivity, in the past. The population of miners/slaves, guards, etc., would have been subject to bioaccumulation of heavy metals, which conceivably would have led to detrimental effects on their health. Inhalation and ingestion of particulate pollutants cannot be discounted. It is argued that the population may have been further weakened as a consequence of food shortage, due to reduced plant productivity, as cereals are important foods for both humans and the animals upon which they are dependent. A sizeable mining community could only have been maintained by large-scale importation of food or a massive intensification of agricultural activity.

Microfabrication by use of a spatial light modulator in the ultraviolet: experimental results

We report the development of a new microstereophotolithography technique for creation of three-dimensional microcomponents by use of a planar, layer-by-layer process of exposure, in which a spatial light modulator is used as a dynamic lithographic mask. The system operates in the UV to take advantage of the wide supply of commercially available photopolymers designed for conventional stereolithography. With this novel procedure it is possible to build components with feature sizes as small as a few micrometers. The experimental setup is briefly described, and the first microcomponent fabricated by this system is shown.

UV Microstereolithography System that uses Spatial Light Modulator Technology

A new stereophotolithography technique utilizing a spatial light modulator (SLM) to create three-dimensional components with a planar, layer-by-layer process of exposure is described. With this procedure it is possible to build components with dimensions in the range of 50 mum-50 mm and feature sizes as small as 5 mum with a resolution of 1 mum. A polysilicon thin-film twisted nematic SVGA SLM is used as the dynamic photolithographic mask. The system consists of eight elements: a UV laser light source, an optical shutter, beam-conditioning optics, a SLM, a multielement reduction lens system, a high-resolution translation stage, a control system, and a computer-aided-design system. Each of these system components is briefly described. In addition, the optical characteristics of commercially available UV curable resins are investigated with nondegenerate four-wave mixing. Holographic gratings were written at a wavelength of 351.1 nm and read at 632.8 nm to compare the reactivity, curing speed, shrinkage, and resolution of the resins. These experiments were carried out to prove the suitability of these photopolymerization systems for microstereolithography.

The immunohistochemical detection of cripto-1 in benign and malignant human bladder

The recently identified epidermal growth factor-related peptide cripto-1 has been previously implicated in the development of the malignant phenotype. The identification of gene products that can act as prognostic markers in bladder cancer would be value in determining the management of this heterogeneous group of patients. This study examines cripto-1 expression in benign and malignant bladder using immunohistochemical techniques. The expression of cripto-1 protein in benign and malignant bladder was examined in 45 bladder tumours (Ta/T1 n = 26, T2 n = 5, T3/T4 n = 14) and six benign controls. All 45 tumours showed positive cytoplasmic staining for cripto-1, including areas of carcinoma in situ. None of the six benign controls showed any evidence of positive cripto-1 staining. Twenty-three (60 per cent) bladder tumours had areas of papillary tumour that showed strong positive staining for cripto-1 as opposed to six (29 per cent) sections of histologically normal urothelium adjacent to tumour (P < 0.05). There was no association between cripto-1 staining and tumour grade, stage, or clinical outcome. Cripto-1 protein appears to be specifically expressed in malignant and benign adjacent urothelium of patients with bladder cancer. Its clinical significance, however, remains to be determined.

The role of natural anti-Gal alpha 1-3Gal antibodies in hyperacute rejection of pig-to-baboon cardiac xenotransplants

Xenoreactive natural antibodies in humans and higher primates are directed predominantly at Gal alpha 1-3Gal. These antibodies are thought to initiate hyperacute rejection of porcine organ xenografts. The contribution of anti-Gal alpha 1-3Gal antibodies to the xenoractive natural antibody repertoire and to the initiation of hyperacute rejection was tested in a pig-to-baboon cardiac xenograft model. Anti-Gal alpha 1-3Gal antibodies were depleted from baboons by extracorporeal absorption of anti-Gal alpha 1-3Gal antibodies from plasma using columns with a matrix bearing Gal alpha 1-3Galb1-4GlcNAc. Specific removal of anti-Gal alpha 1-3Gal antibodies was achieved prior to transplantation as demonstrated by immunoassay. Porcine hearts were then transplanted into these baboons and the outcome of the transplants was analysed. Immunofluorescence revealed little deposition of baboon antibodies in the grafts. The porcine hearts did not undergo hyperacute rejection even though complement activity was approximately 90% of baseline at the time of transplantation. These findings demonstrate that anti-Gal alpha 1-3Gal antibodies constitute a major fraction of xenoreactive natural antibodies in primate blood and that these antibodies contribute significantly to the pathogenesis of hyperacute xenograft rejection.

An association between optic glioma and other tumours of the central nervous system in neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) has a very heterogeneous phenotype. It is not currently possible to predict which patients will have mild disease and which will develop serious complications. Medical management of patients with NF1 might be improved if subgroups of patients who are at especially high (or low) risk for particular complications could be identified. We have begun an analysis of NF1 patients in the National Neurofibromatosis Foundation International Database (NNFFID) to identify possible associations between the occurrence of clinical features. A striking association has been observed between the presence of optic glioma and of other central nervous system (CNS) tumours in NF1 patients. This association is not dependent on the effect of age. No association is seen between optic glioma and non-CNS neoplasms. The association of optic glioma and other intracranial neoplasms in patients with NF1 suggests that there are fundamental pathophysiological differences between patients with and without optic glioma.

The effect of placing an aortic Wallstent across the renal artery origins in an animal model

OBJECTIVES

To assess the effect on renal blood flow and renal function of placing a Wallstent (Schneider (Europe) AG) across the renal artery origins in an animal model.

DESIGN

Laboratory animal study.

MATERIALS AND METHODS

Six Large White pigs had Wallstents placed across the origins of one or both renal arteries. Preoperative jugular venous blood samples were submitted for blood count and urea and electrolyte estimation. The pigs were recovered for 6 weeks. At sacrifice the renal arteries and their origins were examined by aortography and direct pressure measurements were recorded from the renal arteries and both the stented and unstented portions of the aorta. Renal venous blood samples were submitted for blood count, urea and electrolyte and renin estimation while renal arterial blood samples were submitted to examination for red blood cell fragmentation. The aorta with contained stent, renal arteries and kidneys were submitted for histological examination.

RESULTS

At sacrifice no renal arteries had occluded and the stent-covered origins appeared normal with no evidence of stenosis. This was confirmed histologically. There was no statistically significant difference between the arterial pressures measured in the stented and unstented portions of aorta and the renal arteries whether or not their origins had been covered by the stent. There was no statistically significant difference between the urea and electrolyte and renin levels of renal venous blood samples irrespective of whether or not the relevant kidney had a stent across its renal artery origin. Renal arterial blood samples showed no evidence of red blood cell fragmentation and histological examination of the kidneys showed no evidence of infarction or micro-emboli. Examination of the specimens by light and scanning electron microscopy demonstrated partial endothelialisation of the stents but the renal artery origins remained widely patent despite being crossed by at least one wire in all cases.

CONCLUSIONS

It may be necessary to place stents across renal artery origins during endovascular repair of abdominal aortic aneurysms. It would appear that covering renal artery origins with a Wallstent has no effect on renal perfusion pressure or function in this short-term animal model.

Reduction in the level of Gal(alpha1,3)Gal in transgenic mice and pigs by the expression of an alpha(1,2)fucosyltransferase

Hyperacute rejection of a porcine organ by higher primates is initiated by the binding of xenoreactive natural antibodies of the recipient to blood vessels in the graft leading to complement activation. The majority of these antibodies recognize the carbohydrate structure Gal(alphal,3)Gal (gal epitope) present on cells of pigs. It is possible that the removal or lowering of the number of gal epitopes on the graft endothelium could prevent hyperacute rejection. The Gal(alpha1,3) Gal structure is formed by the enzyme Galbeta1,4GlcNAc3-alpha-D-galactosyltransferase [alpha(1,3)GT; EC 2.4.1.51], which transfers a galactose molecule to terminal N-acetyllactosamine (N-lac) present on various glycoproteins and glycolipids. The N-lac structure might be utilized as an acceptor by other glycosyltransferases such as Galbeta1,4GlcNAc 6-alpha-D-sialyltransferase [alpha(2,6)ST], Galbeta1,4GlcNAc 3-alpha-D-Sialyltransferase [alpha(2,3)ST], or Galbeta 2-alpha-L-fucosyltransferase [alpha(1,2)FT; EC 2.4.1.691, etc. In this report we describe the competition between alpha(1,2)FT and alpha(1,3)GT in cells in culture and the generation of transgenic mice and transgenic pigs that express alpha(1,2)Fr leading to synthesis of Fucalpha,2Galbeta- (H antigen) and a concomitant decrease in the level of Gal(alpha1,3)Gal. As predicted, this resulted in reduced binding of xenoreactive natural antibodies to endothelial cells of transgenic mice and protection from complement mediated lysis.

Flow cytometric immunofluorescence assay for detection of antibodies to human immunodeficiency virus type 1 using insoluble precursor forms of recombinant polyproteins as carriers and antigens

A new serological assay, the recombinant flow cytometric immunofluorescence assay (r-FIFA), was developed for the early detection of human immunodeficiency virus type 1 (HIV-1) antibodies by using recombinant insoluble forms of HIV-1 Gag-p45, Gag-gp41 chimeric protein, gp160, Po197 polyprotein as antigens and autologous carriers through flow cytometry. These recombinant proteins were expressed in insect cells by a baculovirus expression system. Eight anti-HIV-1 seroconversion panels, a low-titer anti-HIV-1 panel from Boston Biomedica Inc. (BBI), and three HIV-1 seroconversion specimens from the Provincial Health Laboratory of Ontario, Toronto, Ontario, Canada (PHL), were tested and analyzed by r-FIFA. In sensitivity comparisons between r-FIFA and tests licensed by the U.S. Food and Drug Administration, which were used to test all of the HIV-1 panels from BBI, detection of HIV-1 antibody by r-FIFA was on average greater than 20 days earlier than that by enzyme immunoassay. The sensitivity of r-FIFA has permitted the detection of HIV-1-specific immunoglobulin G (IgG), IgM, and IgA antibodies during seroconversion. A kinetic analysis of HIV-1 antibody production of r-FIFA has shown that either IgG or IgM, or both, can be detected, depending on the phase and type of the immune response in the HIV-1-infected individual. Both primary and secondary immune responses were observed during this period. The r-FIFA results suggest that implementation of r-FIFA may significantly reduce the "window" period from the time of infection to the time of seroconversion, with earlier detection of antibodies after initial infection. This would also make it possible for us to understand the immune response and the precise mechanisms of immunopathogenesis in the early period of HIV-1 infection.

A new animal model for abdominal aortic aneurysms:initial results using a multiple-wire stent

OBJECTIVES

The effect of a plain 48-wire self-expanding flexible stent (Wallstent-Schneider (Europe) AG) on abdominal aortic aneurysms has been studied in a new animal model.

METHODS

Aneurysms were created by interposing fusiform segments of glutaraldehyde-tanned bovine internal jugular vein into the infrarenal aortas of 12 Large White pigs. The first six pigs were assessed after 6 weeks by ultrasonography and arteriography; they were then sacrificed for pathological examination. Endovascular placement of the stents, 2 weeks after aneurysm creation, was performed under arteriographic control in the next six pigs. These pigs were assessed by ultrasonography and arteriography 6 weeks after stenting; they were then sacrificed for pathological examination.

RESULTS

At 6 weeks the aneurysms in the first group were pulsatile with partial endothelialisation and no mural thrombus. Placement of the stent in the second group was accomplished easily. Stenting resulted in an immediate reduction in wall pulsatility of all aneurysms and thrombosis of the excluded aneurysm sac occurred in three cases. In the other three cases the pulse pressure in the sac was reduced. In all cases there was a significant reduction in maximum aneurysm diameter when measured 6 weeks after stenting.

CONCLUSIONS

A pulsatile, non-thrombogenic aortic aneurysm model approaching human dimensions has been successfully developed for the study of endoprostheses prior to their clinical use. Endovascular placement of a plain, multiple-wire Wallstent was associated with reductions in aneurysm pulsatility, pulse pressure within the sac and maximum aneurysm diameter over the study period. Stenting was associated with thrombosis of the excluded aneurysm sac in 50% of cases.