Colorectal carcinomas from Middle East. Molecular and tissue microarray analysis of genomic instability pathways

To evaluate the overall incidence of microsatellite instability [MSI], hereditary non polyposis colorectal cancer, and tumor supressor gene [TP53] mutations in Saudi colorectal carcinomas. We studied the MSI pathway in Saudi colorectal cancers [CRC] from 179 unselected patients using 2 methods: MSI by polymerase chain reaction, and immunohistochemistry detection of mutL homologs 1 and mutS homologs 2 proteins. The TP53 mutations were studied by sequencing exons 5, 6, 7, and 8. Of the 150 colorectal carcinomas analyzed for MSI, 16% of the tumors showed high level instability [MSI-H], 19.3% had low-level instability [MSI-L] and the remaining 64% tumors were stable. Survival of the MSI-H group was better as compared to the MSI-L or microsatellite stable group [p=0.0217]. In the MSI-H group, 48% were familial MSI tumors, which could be attributable to the high incidence of consanguinity in the Saudi population. The TP53 mutations were found in 24% of the cases studied. A high proportion of familial MSI cases and a lower incidence of TP53 mutations are some of the hallmarks of the Saudi colorectal carcinomas, which need to be explored further

Congenital acinar dysplasia. Familial cause of a fatal respiratory failure in a neonate

Pulmonary hypoplasia is a rare cause of pulmonary insufficiency, and has a significant rate of morbidity and mortality among affected infants. In most cases, pulmonary hypoplasia is secondary to underlying abnormalities. These may include space occupying lesions, as in infants with congenital diaphragmatic hernia; malformation of chest wall resulting in a small thoracic cavity; severe and prolonged oligohydramnios; and neuromuscular disorders, which prevent normal fetal chest expansion. All lead to poor lung development. Primary pulmonary hypoplasia as a result of congenital acinar dysplasia is exceedingly rare and is diagnosed by exclusion of all known etiologies of secondary pulmonary hypoplasia