Current challenges in cystic fibrosis screening

CFTR polymorphisms in patients with alcoholic chronic pancreatitis

INTRODUCTION

Pancreas susceptibility to alcohol is variable and only 5-10% of chronic alcohol abusers develop chronic pancreatitis; the role of genetic factors in this process is unknown. The CFTR gene encodes a protein that acts on epithelial cells and plays a key role in normal exocrine pancreatic function.

METHODS

This study investigated the frequency of polymorphisms in intron 8 of the CFTR gene in patients with alcoholic chronic pancreatitis. Three groups of patients were studied: group A - 68 adult alcoholics with a diagnosis of chronic pancreatitis; group B - 68 adult alcoholics without pancreatic disease or liver cirrhosis and group C - 104 healthy nonalcoholic adults.

RESULTS

T5/T7 genotype was more frequent in group A (11.8%) than in group B (2.9%) (p = 0.0481), and there was no statistical difference when groups A and C (5.8%) were compared (p = 0.1317). The haplotype combination (TG)10-T7/(TG)11-T7 was more frequent in groups B (23.5%) and C (20.2%) than in group A (7.3%) (p = 0.0080 and 0.0162).

CONCLUSION

There are differences when these three groups are compared and individuals with T5/T7 genotype might have a greater risk of developing chronic pancreatitis when they become chronic alcoholics.

A comparative study of five technologically diverse CFTR testing platforms

Multiple cystic fibrosis (CF) testing platforms, using diverse and rapidly evolving technologies, are available to clinical laboratories commercially or for evaluation. Considerations when choosing a CF platform may include: sensitivity, specificity, accuracy, signal discrimination, ability to genotype, ability to reflex test, no calls/repeat rate, composition of mutation panel, hands-on time, start-to-finish time, integration into laboratory workflow, data analysis methods, flexibility regarding custom test design, and required instrumentation. Mindful of these considerations, we evaluated five technologically diverse CF platforms: 1) eSensor, an electronic detection assay system; 2) InPlex, a signal amplification methodology using a microfluidics card; 3) oligonucleotide ligation assay, an electrophoretic-based separation of amplicon-derived ligation-generated products; and two liquid bead arrays; 4) Signature, a direct hybridization assay using allele-specific capture probes; and 5) Tag-It, an assay using allele-specific primer extension and a universal microarray. A core of 150 samples, focusing on mutations in the American College of Medical Genetics/American College of Obstetricians and Gynecologists mutation panel, was tested throughout several runs for each platform. All of the platforms performed comparably in respect to sensitivity, specificity, and no-call rate. As our results indicate, consideration of all of the parameters evaluated may be useful when selecting the most appropriate platform for the specific setting.

Acute and Chronic Bacterial Sinusitis

Sinusitis is one of the most common complaints resulting in physician visits in the United States. An antecedent viral infection of the upper respiratory tract is the most common presentation. Despite its prevalence, most cases resolve spontaneously. Only a small proportion develops a secondary bacterial infection that will benefit from antimicrobial therapy. This article discusses the microbiology and pathogenesis of acute and chronic bacterial sinusitis. The role anaerobic bacterial in chronic and recurrent sinusitis is emphasized, and appropriate antimicrobial regimens are discussed.

Nocturnal hydration--an effective modality to reduce recurrent abdominal pain and recurrent pancreatitis in patients with adult-onset cystic fibrosis

Recurrent abdominal pain and recurrent pancreatitis are common problems associated with some patients with cystic fibrosis (CF). There is no known effective method to prevent recurrent abdominal pain and recurrent pancreatitis in such patients. The objective of this study was to determine whether nocturnal hydration (NH) prevents recurrent abdominal pain and recurrent acute pancreatitis in patients with adult-onset CF. Adult CF patients who were referred to our Pancreatic Diseases Clinic for recurrent abdominal pain and pancreatitis were enrolled in the study. Each patient was encouraged to drink plenty of water during the night and established a 6-month diary (3 months before and 3 months after NH was initiated), recording the frequency and severity of their abdominal pain, the amount of pain medication taken, and the volume of their water intake. We also reviewed the number of doctor's clinic visits, emergency room visits, and hospitalizations for about 1 year before and 1 year after the initiation of the NH. The frequency and the severity of abdominal pain in this group of patients were significantly reduced. The amount of pain medication and the number of emergency room visits and hospitalizations for abdominal pain and acute pancreatitis were reduced. NH is a simple and cost-effective method to prevent recurrent abdominal pain and pancreatitis in patients with adult-onset CF.

Misdiagnosing cystic fibrosis in the era of gene analysis: case reports

We present a scenario of how gene analysis plays a confusing role in the diagnosis of cystic fibrosis (CF). One of the two siblings we are presenting here was initially misdiagnosed as having CF, based on the two CF gene mutations identified by gene analysis. A CF gene study on the other sibling years later, however, led to further investigation and eventually to a change of diagnosis. As interesting and important as gene analysis is in CF, one must always look at each patient in the big picture. Included in the picture, in addition to the state-of-the-art genotype, is the phenotype, or (to simplify) the back-to-basic clinical manifestations.

What's new in prenatal screening and diagnosis?

This article provides clinicians with an overview of current methods for prenatal genetic screening and diagnosis. Topics include developments in prenatal screening procedures such as ethnicity-based carrier testing, maternal serum screening, and ultrasonography. Diagnostic alternatives to amniocentesis include chorionic villus sampling and preimplantation diagnosis. Future endeavors such as three-dimensional ultrasonography and fetal cell sorting are discussed.

Post-genome molecular diagnostics in obstetrics

PURPOSE OF REVIEW

The intention of this review is to familiarize the practicing clinician with the current status and future direction of molecular testing in obstetrics. As a discipline, obstetrics and gynecology is unique in that it deals with the full spectrum of molecular genetic testing. This spectrum includes infectious disease, neoplasia and inherited diseases. This review will focus on inherited conditions and complex diseases, as it is in this context that we may fully realize the true promise of the human genome and its application to the practice of medicine.

RECENT FINDINGS

Despite the successful sequencing of the human genome, very few new molecular genetic tests have become available. The apparent reason for this lies in the relative paucity of information gleaned from examining the genes themselves. Two new avenues of investigation are presently underway to improve the 'infirmity' of this information archive. Rather than merely looking at differential gene expression, clinician scientists have begun to examine genetic polymorphisms of single and multiple genes within and between individuals in an attempt to explain biologic processes, including disease states. The second avenue involves the characterization of the products of gene expression--proteins. Proteomics, in conjunction with high throughput polymorphism analysis, may enable us to diagnose and treat complex multifactorial diseases.

SUMMARY

Molecular diagnostics for multifactorial diseases will become conceptually and technologically more complex than present DNA testing modalities. The development and ultimate acceptance of these tests will require greater coordination between the medical and scientific communities to ensure that the right technologies are applied to the highest quality samples to answer the most relevant questions.