Contribution of germline PALB2 variants to an unselected and prospectively registered pancreatic cancer patient cohort in Pakistan.

BACKGROUND: Partner and localizer of BRCA2 (PALB2) is a pancreatic cancer (PC) susceptibility gene reported in Caucasians. However, limited data are available among Asians. We investigated the contribution of PALB2 germline variants to Pakistani PC patients. METHODS: 150 unselected and prospectively enrolled PC patients were comprehensively screened for PALB2 variants, using denaturing high-performance liquid chromatography and DNA sequencing. Novel variants were investigated for their pathogenic effect using in-silico tools. Potentially functional variants were screened in 200 controls. RESULTS: Twenty-two different PALB2 variants were identified. A missense variant (p.Arg37His) was identified in a 48-years-old male patient with a family history of breast cancer. Another missense variant (p.Trp898Arg) was identified in a 48-years-old male patient with a family history of esophageal cancer. A novel 3' downstream variant (c.∗480A>G) was detected in a 34-years-old female patient with family history of lung cancer. Another novel 3' downstream variant (c.∗417A>C) was identified in a 41-years-old male patient. All these variants were absent in 200 controls. p.Arg37His and p.Trp898Arg were predicted as likely pathogenic. c.∗417A>C and c.∗480A>G were classified as variants of uncertain significance. CONCLUSION: This is the first study that suggests a minimal contribution of PALB2 variants to PC risk in Pakistani population.

A novel deleterious c.2656G>T MSH2 germline mutation in a Pakistani family with a phenotypic overlap of hereditary breast and ovarian cancer and Lynch syndrome.

BACKGROUND: Hereditary breast and ovarian cancer syndrome (HBOC) and Lynch syndrome (LS) account for a significant proportion of inherited gynecologic malignancies, mainly caused by pathogenic germline mutations in the BRCA1 and BRCA2 genes or in mismatch repair (MMR) genes, such as MLH1 and MSH2. Women harboring deleterious mutations in these genes have increased life-time risks of developing a number of malignancies including ovarian cancer. Since there is a phenotypic overlap of HBOC and LS, timely identification of individuals at-risk of a particular syndrome is crucial in order to optimize cancer risk management. CASE PRESENTATION: We report a novel pathogenic MSH2 mutation, c.2656G > T, which was identified in a 67-year-old female patient with breast cancer, who had previously tested negative for a deleterious mutation in the breast cancer susceptibility genes BRCA1, BRCA2, CHEK2 or RAD51C. The patient reported a personal history of endometrial cancer diagnosed at age 48, and a strong family history of breast and ovarian cancer, as well as several other malignancies within the spectrum of LS. The novel mutation was also found in the index patient's daughter and a niece, who were diagnosed with endometrial and ovarian cancer, respectively. Breast and endometrial tumors from c.2656G > T mutation carriers showed loss of MSH2 and MSH6 protein expression. The mutation was absent in the control population. CONCLUSIONS: Our finding suggests that testing for MMR genes may be of benefit to BRCA1/2 negative families with overlapping HBOC and LS phenotype in Pakistan. It is clinically significant to identify individuals harboring mutations in genes linked with a particular syndrome so that they can benefit from targeted life-saving cancer surveillance and preventive strategies.

Metallic stent insertion to relieve malignant bowel obstruction in a child: a case report.

Self-expandable metallic stents (SEMS) have been widely used in adults to relieve obstruction secondary to colorectal tumours. However, there is a paucity of literature about their use in children, with only a few case reports describing stent insertion in children with benign colonic conditions. There is one case report on a malignant colonic condition in a child by Hussain et al. in the literature. However, due to the rarity of the condition, there are currently no guidelines from learned societies on colorectal SEMS placement in paediatric patients. We share our experience of using a fully covered SEMS to relieve malignant colonic obstruction in a 6 year-old-child, who was on treatment for T cell lymphoma. This was done as a bridge to surgery, thereby allowing planned surgery, and avoiding colostomy in this child, who went on to have colonic resection with primary anastomosis.