Identification of Cystic Lesions by Secondary Screening of Familial Pancreatic Cancer (FPC) Kindreds Is Not Associated with the Stratified Risk of Cancer.

OBJECTIVES: Intraductal papillary mucinous neoplasms (IPMNs) are associated with risk of pancreatic ductal adenocarcinoma (PDAC). It is unclear if an IPMN in individuals at high risk of PDAC should be considered as a positive screening result or as an incidental finding. Stratified familial pancreatic cancer (FPC) populations were used to determine if IPMN risk is linked to familial risk of PDAC. METHODS: This is a cohort study of 321 individuals from 258 kindreds suspected of being FPC and undergoing secondary screening for PDAC through the European Registry of Hereditary Pancreatitis and Familial Pancreatic Cancer (EUROPAC). Computerised tomography, endoscopic ultrasound of the pancreas and magnetic resonance imaging were used. The risk of being a carrier of a dominant mutation predisposing to pancreatic cancer was stratified into three even categories (low, medium and high) based on: Mendelian probability, the number of PDAC cases and the number of people at risk in a kindred. RESULTS: There was a median (interquartile range (IQR)) follow-up of 2 (0-5) years and a median (IQR) number of investigations per participant of 4 (2-6). One PDAC, two low-grade neuroendocrine tumours and 41 cystic lesions were identified, including 23 IPMN (22 branch-duct (BD)). The PDAC case occurred in the top 10% of risk, and the BD-IPMN cases were evenly distributed amongst risk categories: low (6/107), medium (10/107) and high (6/107) (P = 0.63). CONCLUSIONS: The risk of finding BD-IPMN was independent of genetic predisposition and so they should be managed according to guidelines for incidental finding of IPMN.

A common ancestral mutation (C128X) occurring in 11 non-Jewish families from the UK with factor XI deficiency.

Factor XI (FXI) deficiency is a mild bleeding disorder that is particularly common in Ashkenazi Jews, but has been reported in all populations. In Jews, two FXI gene (F11) mutations (a stop codon in exon 5, E117X, type II, and a point mutation in exon 9, F283L, type III) are particularly common, but in other populations a variety of different mutations have been described. In the Basque region of France one mutation, C38R in exon 3, was found in eight of 12 families studied, haplotype analysis suggesting a founder effect. In the course of screening 78 unrelated individuals (including 15 Jewish and 12 Asian) we have found 10 Caucasian non-Jewish patients with the mutation C128X in exon 5. Individuals were investigated because of a personal or family history of bleeding, or finding a prolonged activated partial thromboplastin time. Individuals negative for the type II and type III mutations were screened by a combination of SSCP and heteroduplex analysis. The C128X mutation was found in 10 families (one previously described). Among three individuals with severe FXI deficiency, one was homozygous for the C128X mutation, and two were compound heterozygotes for the C128X and another mutation; other individuals were carriers of the C128X mutation. This is a nonsense mutation producing a truncated protein; individuals have FXI antigen levels concordant with FXI coagulant activity. Haplotype analysis of 11 families, including a further kindred previously reported from the USA, but which originally came from the UK (in which the index patient was homozygous for C128X), suggests a founder effect.

Should we monitor vitamin B12 levels in patients who have had end-ileostomy for inflammatory bowel disease?

BACKGROUND AND AIMS: We examined whether vitamin B12 levels are low following surgery in those patients who have had end-ileostomy for inflammatory bowel disease. PATIENTS AND METHODS: This prospective observational study used the database of a university teaching hospital to identify patients with inflammatory bowel disease with an end-ileostomy constructed more than 30 months previously. Precise diagnosis, disease distribution and details of their surgery were collected from case notes of the 39 eligible patients (18 Crohn's disease, 17 ulcerative colitis, 4 indeterminate colitis). Mean duration since ileostomy formation was 12.53 years. Patients found to be vitamin B12 deficient underwent further investigations to ascertain the cause of their vitamin B12 deficiency (<150 ng/l). RESULTS: There was no significant difference between serum vitamin B12 levels in patients with Crohn's disease and those in patients with ulcerative colitis following end ileostomy formation. Two patients (5.1%) were identified as having vitamin B12 deficiency. One of these had had a panproctocolectomy for Crohn's disease, followed by subsequent resection for ileal obstruction and ongoing small intestinal disease. The other had had colectomy for ulcerative colitis, in whom no cause other than the ileostomy was found for the vitamin B12 deficiency. There was no significant correlation between serum vitamin B12 levels and duration of ileostomy overall or in the disease subgroups. CONCLUSION: We do not recommend routine screening for vitamin B12 deficiency in this group of patients unless they have undergone additional small bowel resection or have ongoing small bowel inflammation.

Nail patella syndrome: a review of the phenotype aided by developmental biology.

Nail patella syndrome (NPS) is an autosomal dominant condition affecting the nails, skeletal system, kidneys, and eyes. Skeletal features include absent or hypoplastic patellae, patella dislocations, elbow abnormalities, talipes, and iliac horns on x ray. Kidney involvement may lead to renal failure and there is also a risk of glaucoma. There is marked inter- and intrafamilial variability. The results of a British study involving 123 NPS patients are compared with previously published studies and it is suggested that neurological and vasomotor symptoms are also part of the NPS phenotype. In addition, the first data on the incidence of glaucoma and gastrointestinal (GI) symptoms in NPS are presented. NPS is caused by loss of function mutations in the transcription factor LMX1B at 9q34. The expansion of the clinical phenotype is supported by the role of LMX1B during development.

The N34S mutation of SPINK1 (PSTI) is associated with a familial pattern of idiopathic chronic pancreatitis but does not cause the disease.

BACKGROUND: Mutations in the PRSS1 gene explain most occurrences of hereditary pancreatitis (HP) but many HP families have no PRSS1 mutation. Recently, an association between the mutation N34S in the pancreatic secretory trypsin inhibitor (SPINK1 or PSTI) gene and idiopathic chronic pancreatitis (ICP) was reported. It is unclear whether the N34S mutation is a cause of pancreatitis per se, whether it modifies the disease, or whether it is a marker of the disease. PATIENTS AND METHODS: A total of 327 individuals from 217 families affected by pancreatitis were tested: 152 from families with HP, 108 from families with ICP, and 67 with alcohol related CP (ACP). Seven patients with ICP had a family history of pancreatitis but no evidence of autosomal dominant disease (f-ICP) compared with 87 patients with true ICP (t-ICP). Two hundred controls were also tested for the N34S mutation. The findings were related to clinical outcome. RESULTS: The N34S mutation was carried by five controls (2.5%; allele frequency 1.25%), 11/87 (13%) t-ICP patients (p=0.0013 v controls), and 6/7 (86%) affected (p<0.0001 v controls) and 1/9 (11%) unaffected f-ICP cases. N34S was found in 4/108 affected HP patients (p=0.724 v controls), in 3/27 (11%) with wild-type and in 1/81 (1%) with mutant PRSS1, and 4/67 ACP patients (all p>0.05 v controls). The presence of the N34S mutation was not associated with early disease onset or disease severity. CONCLUSIONS: The prevalence of the N34S mutation was increased in patients with ICP and was greatest in f-ICP cases. Segregation of the N34S mutation in families with pancreatitis is unexplained and points to a complex association between N34S and another putative pancreatitis related gene.

A new polymorphism for the RI22H mutation in hereditary pancreatitis.

BACKGROUND AND AIMS: Hereditary pancreatitis (HP) is a rare form of recurrent acute and chronic pancreatitis. Mutations in the cationic trypsinogen (protease serine 1, PRSS1) gene have been identified as causing HP. The R122H (previously known as R117H) mutation is the commonest and can be detected by a single and rapid polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP) based technique using the AflIII enzyme. This test however may give a false negative result in the presence of a neutral polymorphism within the enzyme recognition site. The frequency of this event was examined by sequencing studies in patients with HP and in healthy controls. METHODS: Of 60 families identified by the UK and Ireland consortium of EUROPAC (European Registry for Hereditary Pancreatitis and Familial Pancreatic Cancer), 51 were screened for R122H, N29I, and A16V mutations using standard techniques, and by sequencing of all five exons of cationic trypsinogen. RESULTS: Twelve families had the N29I mutation, one family had A16V and, on standard testing, 15 families had the R122H mutation. An additional family with the R122H mutation was found on direct sequencing. The false negative result was due to a neutral polymorphism C-->T at the third base of the codon, not affecting the amino acid coded for, destroying the AflIII restriction site. This polymorphism was not observed in 50 DNA specimens (100 chromosomes) from controls nor from 50 individuals from PRSS1 mutation negative HP families. A novel mutation specific PCR was developed to avoid this pitfall. CONCLUSIONS: One of the 16 families with HP and an R122H mutation contained a polymorphism affecting the AflIII restriction site. Adoption of an alternative R122H assay is important for genetic studies in individuals with apparent HP.

Cystic fibrosis in infertility: screening before assisted reproduction: opinion.

Cystic fibrosis (CF) is the most common autosomal recessive disease in Caucasians. In 97-98% of men with CF, bilateral congenital absence of the vas deferens (CBAVD) blocks the transport of spermatozoa resulting in azoospermia. Abnormalities in sperm parameters have also been identified in males with CF. To date, over 800 disease-causing mutations of the CF transmembrane conductance regulator (CFTR) gene have been identified (also called ABCC7). Current legislation suggests that prior to intracytoplasmic sperm injection (ICSI) treatment, men with CBAVD or unexplained oligozoospermia should be considered for screening. If the male is negative with routine screening then the female partner is not screened. This is fundamentally wrong because if the female is screened and is found to be CF positive on routine testing, her partner would then need the fullest possible investigation of the CFTR gene. It is ideal to screen both partners in cases of oligozoospermia. However, if the resources are stretched, then only the female needs to be routinely screened because if she is negative, then the couple's residual risk of having a CF or CBAVD child will be reduced to 1:960. Only when the female is found to be a carrier does the male partner need routine screening followed by full testing for known mutations.

Small bowel bacterial overgrowth in subjects living in residential care homes.

OBJECTIVES: in elderly people, bacterial overgrowth of the small bowel may be occult. The significance of positive breath tests are uncertain: many fit elderly subjects with positive tests show no evidence of malabsorption. We assessed the prevalence and significance of bacterial overgrowth in the small bowel in a relatively unselected elderly population. METHODS: residents of seven elderly people's homes had a glucose hydrogen breath test. A medical history and anthropomorphic measurements were recorded. Volunteers with positive breath tests were given doxycycline. After 4 months all volunteers were reassessed. RESULTS: of 140 residents, 62 were tested. Nine (14.5%) had a positive breath test. There was no difference in anthropomorphic and bowel habit data between those with positive and those with negative breath tests. After 4 months of antibiotic treatment, volunteers with a positive breath test had increased weight and body mass index, while those with a negative test had decreased weight and body mass index. CONCLUSIONS: the percentage of volunteers with a positive breath test was much lower than in previous studies. This may be due to the relatively unselected nature of the volunteers. Treatment of bacterial overgrowth resulted in a small but significant improvement in anthropometric indices. The lack of association of positive breath tests with baseline anthropomorphic measurements or bowel habit highlights the occult nature of the bacterial overgrowth and questions its clinical importance.

Molecular diagnosis of spinal muscular atrophy.

The frequency of deletions within the survival motor neurone (SMN) and neuronal apoptosis inhibitory protein (NAIP) genes in patients with spinal muscular atrophy (SMA), and the impact of this on the diagnosis and prenatal diagnosis of SMA, were investigated by molecular analysis of stored DNA and retrospective review of case notes. In type I SMA, 16 of 17 cases were homozygously deleted for exons 7 and 8 of SMN, 14 of 17 were homozygously deleted for exon 5 of NAIP, and 13 of 17 were deleted for both. In types II and III SMA, seven of nine cases were deleted for exons 7 and 8 of SMN. Deletions of SMN and NAIP occurred in four of nine cases. With one exception, the deletion genotypes of probands, affected siblings, and terminated fetuses were identical. Molecular studies are replacing conventional investigations for SMA and have a high uptake prenatally.

Missense mutation clustering in the survival motor neuron gene: a role for a conserved tyrosine and glycine rich region of the protein in RNA metabolism?

The Survival Motor Neuron (SMN) gene shows deletions in the majority of patients with Spinal Muscular Atrophy (SMA), a disease of motor neuron degeneration. To date only two missense mutations have been reported in SMN in patients with SMA. The fact that no SMN-homologues have been forthcoming from data-base searching has resulted in a lack of hypotheses concerning the structural and functional consequences of these mutations. Recently SMN has been shown to interact with heterogeneous nuclear ribonucleoproteins (hnRNPs) suggesting a role in mRNA metabolism. We describe a novel missense mutation and the subsequent identification of a triplicated tyrosine-glycine (Y-G) peptide sequence at the C-terminal of SMN which encompasses each of the three predicted amino acid sequence substitutions. We have identified apparent orthologues of SMN in Caenorhabditis elegans and Schizosaccharomyces pombe. These sequences retain the highly conserved Y-G motif and provide additional support for a role of SMN in mRNA metabolism.

Hereditary pancreatitis and familial pancreatic cancer.

Important advances in the understanding of pancreatic diseases have taken place through the application of molecular methods in the study of the inherited form of pancreatitis and pancreas cancer. Mutations of the cationic trypsinogen gene have been found to be causative for hereditary pancreatitis with important implications for the molecular pathogenesis of acute and chronic pancreatitis. A variety of cancer syndromes involving the P16 and BRCA2 genes, for example, also lead to pancreatic cancer, but the gene responsible for familial pancreatic cancer has not been identified so far. The establishment of a European Registry of Hereditary Pancreatitis and Pancreatic Cancer (EUROPAC) will facilitate future developments.

Prevalence of Helicobacter pylori in respiratory physicians performing bronchoscopy: a comparison with gastroenterologists using the carbon 13 urea breath test.

BACKGROUND: The mode of transmission of Helicobacter pylori is unclear, but it has been shown that gastroenterologists are at a greater risk of acquiring the infection when performing endoscopy. The current study was designed to assess the risk H. pylori infection in respiratory physicians performing bronchoscopy compared to an at-risk group of gastroenterologists. We were interested in identifying whether the oral cavity is important in the transmission of H. pylori. MATERIALS AND METHODS: Respiratory physicians and gastroenterologists in southern England and Wales were invited to participate in the study. Medical, personal, and professional details were recorded, and H. pylori status was established using a carbon 13 urea breath test. RESULTS: The study included 30 gastroenterologists and 30 respiratory physicians. The groups were similar for age (mean age, 46.2 years [SD 8.7] and 43.9 years [SD 8.5], respectively), number of years in practice (mean, 16.1 [6.8] and 13.2 [5.5], respectively), amount of Third-World travel, and glove and drug use (antacids, H2 antagonists, proton pump inhibitors, promotility agents, and bismuth). The prevalence of upper gastrointestinal symptoms (indigestion, heartburn, abdominal pain) and history of previous peptic ulcer or hiatus hernia were similar for both groups. Fifteen of thirty gastroenterologists and three of thirty respiratory physicians had positive breath tests (chi square, p < .001, 1 df). There was no relation between age and H. pylori status. Within the group of gastroenterologists, performance of endoscopy without gloves for longer than 7 years was associated with an increased prevalence of infection (> 7 years, 11 of 15 breath-test-positive; < 7 years, 4 of 15 breath-test-positive [chi square, p = .01, 1 df]). CONCLUSIONS: Gastroenterologists in this study appeared to be at risk of infection, whereas respiratory physicians are not. Gastroenterologists who wear gloves during endoscopy appear to be at lower risk of H. pylori infection.

The gene for X-linked hypophosphataemic rickets maps to a 200-300kb region in Xp22.1, and is located on a single YAC containing a putative vitamin D response element (VDRE).

The location of the HYP gene, which determines X-linked hypophosphataemic rickets, has been refined considerably by linkage analysis, and three new microsatellite primers isolated, Cap32 (DXS7473), Cap29 (DXS7474) and 7v2 (DXS7475). The locations of four other markers have also been determined (DXS1226, AFMa176zb1, AFMa152wc5, and AFM346azc1). Markers Cap29 and Cap32 are the closest distal markers to the gene with zetamax=11.93, thetamax= 0.018 and zetamax=12.03, thetamax = 0.015 respectively. Both Cap29 and Cap32 are proximal to DXS365 and AFMa176zb1, as deduced by screening non-chimaeric yeast artificial chromosomes (YACs) from a contig spanning the HYP gene. A single crossover places AFMa176zbl distal to the disease gene. There are no recombinations between 7v2 and HYP (zetamax=12.9, thetamax=0.0), or between 7v2 and adjacent markers Cap32, Cap29, AFMa176zb1, DXS1683 and DXS365. However screening of YAC clones encompassing the HYP gene and also P1 clones localises 7v2 distal to Cap29 and Cap32, and proximal to DXS443. Marker DXS1226 is placed outside the region containing the gene, and is located proximal to DXS274 as confirmed by a crossover for this marker and DXS41 against HYP and its presence on YAC 83B05. Genetic mapping of CEPH pedigrees, and screening of YACs places AFMa152wc5 and AFMa346zcl between DXS1683 and DXS1052. The following gene marker map presents the best order for the HYP region: Xptel-DXS43-DXS999-DXS443-(DXS365/DXS74 75/AFMa176zb1)-(DXS7474/DXS7473)-HYP- DXS1683-(AFMa152wc5/AFMa346zc1)-DXS1052-DXS 274 -(DXS41/DXS1226)-Xcen. The distance between the cluster of distal flanking markers Cap29 (DXS7474), Cap32 (DXS7473), and DXS1683 is approximately 300 kb, as deduced from physical map data from a YAC contig spanning the gene. Thus the gene for HYP is contained within a single YAC (900AO472). Of further interest, is the location of a putative vitamin D response element (VDRE) on this YAC.

PCR techniques for deletion, linkage, and mutation analysis in duchenne/becker muscular dystrophy.

Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) are allelic disorders caused by mutations in the dystrophin gene. The molecular genetic analysis of these disorders is among the most difficult encountered in a routine diagnostic laboratory. The analysis is made difficult by the size and structure of the gene, which is 2.4 Mb in size, and comprises 79 exons encoding a 14-kb mRNA transcript (1, 2). The exons are all small (<200 bp), whereas the introns vary from 109 bp to >200 kb. The interpretation of results is hampered further by the incidence of new mutation (approximately one-third of DMD cases), the greater than normal level of recombination across the gene (approx 10% [3, 4]), and finally the occurrence of a significant level of germline mosaicism (5, 6).

Omeprazole 10 mg or 20 mg once daily in the prevention of recurrence of reflux oesophagitis. Solo Investigator Group.

This study determined the optimal maintenance dose of omeprazole in reflux oesophagitis. One hundred and ninety three patients rendered asymptomatic and healed after four or eight weeks omeprazole were randomised double blind to 10 mg omeprazole once daily (n = 60 evaluable), 20 mg omeprazole once daily (n = 68), or placebo (n = 62) for one year or until symptomatic relapse. Each omeprazole regimen was superior to placebo in preventing both symptomatic relapse (life table analysis, p < 0.001) and endoscopically verified relapse (p < 0.001). At 12 months, the life table endoscopic remission rates (proportions of patients without grade > or = 2 oesophagitis) were: 50% (95% confidence intervals 34 to 66%) with 10 mg omeprazole once daily, 74% (62 to 86%) with 20 mg omeprazole once daily, and 14% (2 to 26%) with placebo. At 12 months, the life table symptomatic remission rates (proportions of patients asymptomatic or with mild symptoms) were: 77% (64 to 89%) with 10 mg omeprazole once daily, 83% (73 to 93%) with 20 mg omeprazole once daily, and 34% (16 to 52%) with placebo. Both 10 mg and 20 mg omeprazole once daily were effective in prolonging the remission of reflux oesophagitis: 10 mg may be appropriate to start longterm treatment, though the existence of a dose response relation means that 20 mg once daily may be effective in patients for whom 10 mg once daily is suboptimal.

Splanchnic blood flow in patients with cirrhosis and portal hypertension: investigation with duplex Doppler US.

PURPOSE: To investigate splanchnic blood flow changes in patients with hepatic cirrhosis and portal hypertension. MATERIALS AND METHODS: Duplex Doppler ultrasound (US) was used to measure blood flow in the superior mesenteric artery (SMA) and splenic artery in 20 patients with biopsy-proved cirrhosis and clinical evidence of portal hypertension, and in 20 healthy volunteers who were matched for age and sex. RESULTS: Mean SMA and splenic artery blood flow was significantly greater in the patients than in healthy subjects. Neither SMA nor splenic artery blood flow was increased in patients with normal-sized spleens; however, blood flow was significantly elevated in patients with splenomegaly. Total splanchnic blood flow in patients was also significantly elevated compared with healthy subjects. Total splanchnic blood flow in patients with normal-sized spleens was not significantly elevated compared with healthy subjects, but splanchnic flow was significantly increased in patients with splenomegaly. CONCLUSION: Blood flow is increased in the SMAs and splenic arteries of patients with cirrhosis and portal hypertension. Increased splanchnic blood flow associated with cirrhosis may occur exclusively in patients with splenomegaly.

Occurrence of Duchenne dystrophy in Klinefelter's syndrome.

A boy with Duchenne muscular dystrophy and facial dysmorphism in conjunction with Klinefelter's genotype 47XXY is presented; this is an unusual situation with two genetic errors evolving over two generations. Karyotyping should be considered in boys with Duchenne muscular dystrophy who have unusual features.