Louis Vitone

Peutz-Jeghers syndrome and screening for pancreatic cancer.

Cancer risk, including pancreatic, is high in those with Peutz–Jeghers syndrome (PJS). It has been suggested that such patients should undergo screening for pancreatic cancer.

Palladin Mutation Causes Familial Pancreatic Cancer: Absence in European Families

We read with interest the article published in PLoS Medicine by Pogue-Geile et al. [1] reporting an apparent mutation in the KIAA0992 splice variant of the palladin gene in a family previously reported to have a high incidence of pancreatic cancer. Pogue-Geile and others had previously established that the 4q32–34 locus segregated with pancreatic cancer in this family by screening for pre-neoplastic lesions, which could then be used as a marker for mutation carriers [2]. In the PLoS Medicine paper the authors show that the mutation in palladin is on the 4q32–34 haplotype that segregates with the disease. The European Registry of Hereditary Pancreatitis and Familial Pancreatic Cancer (EUROPAC) and the German National Case Collection for Familial Pancreatic Cancer (FaPaCa) have recently shown that a mutation on 4q32–34 is unlikely to explain pancreatic cancer in a majority of our European families, but we did not rule out segregation with the disease in a minority of families [3]. Naturally we were keen to establish if the mutation seen in Family X from America was seen in any of our families, and so we have sequenced the locus in 74 individuals who were either affected by pancreatic cancer or who are obligate carriers (assuming autosomal dominant inheritance) of the disease mutation (in 74 families). We have also sequenced the locus in 14 affected individuals from 14 families with familial multiple mole melanoma with cases of pancreatic cancer (FAMMM-PC) [4] and nine sporadic pancreatic cancer patients of less than 50 years of age. We did not identify the mutation in any of the individuals, neither as a heterozygote or a homozygote. This does not of course mean that other mutations in coding or non-coding regions of this variant of palladin or other variants are absent from European families. However, it is noteworthy that the phenotype of Family X is significantly different from the phenotype common to the families on the EUROPAC/FaPaCa registries. In particular, the incidence of diabetes in our families is relatively low, except where the diabetes is a direct consequence of development of cancer [3]. This presentation contrasts strongly with the family harbouring the palladin mutation [1,2], where diabetes was common. It is possible that Family X (and the association with palladin mutation) is not typical of the familial pancreatic cancer syndrome.

Evaluation of the 4q32-34 Locus in European Familial Pancreatic Cancer

Background: Familial pancreatic cancer (FPC) describes a group of families where the inheritance of pancreatic cancer is consistent with an autosomal-dominant mode of inheritance. The 4q32-34 region has been previously identified as a potential locus for FPC in a large American family. Methods: The region was allelotyped in 231 individuals from 77 European families using nine microsatellite markers, and haplotyping was possible in 191 individuals from 41 families. Families were selected based on at least two affected first-degree relatives with no other cancer syndromes. Results: Linkage to most of the locus was excluded based on LOD scores less than −2.0. Eight families were excluded from linkage to 4q32-34 based on haplotypes not segregating with the disease compared with a predicted six to seven families. Two groups of families were identified, which seem to share common alleles within the minimal disease-associated region of 4q32-34, one group with an apparently earlier age of cancer death than the other pancreatic cancer families. Four genes were identified with potential tumor suppressor roles within the locus in regions that could not be excluded based on the LOD score. These were HMGB2, PPID, MORF4, and SPOCK3. DNA sequence analysis of exons of these genes in affected individuals and in pancreatic cancer cell lines did not reveal any mutations. Conclusion: This locus is unlikely to harbor a FPC gene in the majority of our European families. (Cancer Epidemiol Biomarkers Prev 2006;15(10):1948–55)

The variable phenotype of the p.A16V mutation of cationic trypsinogen (PRSS1) in pancreatitis families

Objective To characterise the phenotypes associated with the p.A16V mutation of PRSS1. Design Clinical and epidemiological data were collected for any family in which a p.A16V mutation was identified, either referred directly to the European Registry of Hereditary Pancreatitis and Familial Pancreatic Cancer or via a collaborator. DNA samples were tested for mutations in PRSS1, SPINK1, CFTR and CTRC. Patients Participants were recruited on the basis of either family history of pancreatitis (acute or chronic) or the results of genetic testing. Families were categorised as having hereditary pancreatitis (HP), idiopathic disease or pancreatitis in a single generation. HP was defined as ≥2 cases in ≥2 generations. Main outcome measures Onset of painful episodes of pancreatitis, death from pancreatic cancer, diagnosis of diabetes mellitus and exocrine pancreatic failure. Results Ten families with p.A16V mutations were identified (22 affected individuals): six HP families, three with idiopathic disease and one with only a single generation affected. The median age of onset, ignoring non-penetrants, was 10 years (95% CI 5 to 25). There were eight confirmed cases of exocrine failure, four of whom also had diabetes mellitus. There were three pancreatic cancer cases. Two of these were confirmed as p.A16V carriers, only one of whom was affected by pancreatitis. Those with p.A16V pancreatitis were compared to affected individuals with p.R122H, p.N29I and no PRSS1 mutation. No significant differences were proven using logrank or Mann–Whitney U tests. Conclusions Penetrance of p.A16V is highly variable and family dependent, suggesting it contributes to multigenic inheritance of a predisposition to pancreatitis.

Obturator Hernia – MRI Image

Obturator hernia although considered a rare entity is the most frequently encountered pelvic floor hernia. Since the first published report in the 18th century, their unusual and unfamiliar clinical presentation still represents a diagnostic dilemma for the modern day clinician. A detailed history and clinical examination in our thin, elderly female patient who presented with intermittent small bowel obstruction and symptoms of right obturator nerve compression with a positive Howship-Romberg sign was crucial in establishing a diagnosis. Sophisticated radiologic modalities such as MRI as shown below in the case of our patient can reliably confirm the diagnosis of obturator hernia.