The skeletal phenotype of achondrogenesis type 1A is caused exclusively by cartilage defects.

Inactivating mutations in the ubiquitously expressed membrane trafficking component GMAP-210 (encoded by Trip11) cause achondrogenesis type 1A (ACG1A). ACG1A is surprisingly tissue specific, mainly affecting cartilage development. Bone development is also abnormal, but as chondrogenesis and osteogenesis are closely coupled, this could be a secondary consequence of the cartilage defect. A possible explanation for the tissue specificity of ACG1A is that cartilage and bone are highly secretory tissues with a high use of the membrane trafficking machinery. The perinatal lethality of ACG1A prevents investigating this hypothesis. We therefore generated mice with conditional Trip11 knockout alleles and inactivated Trip11 in chondrocytes, osteoblasts, osteoclasts and pancreas acinar cells, all highly secretory cell types. We discovered that the ACG1A skeletal phenotype is solely due to absence of GMAP-210 in chondrocytes. Mice lacking GMAP-210 in osteoblasts, osteoclasts and acinar cells were normal. When we inactivated Trip11 in primary chondrocyte cultures, GMAP-210 deficiency affected trafficking of a subset of chondrocyte-expressed proteins rather than globally impairing membrane trafficking. Thus, GMAP-210 is essential for trafficking specific cargoes in chondrocytes but is dispensable in other highly secretory cells.

Desire for information and involvement in treatment decisions: elderly cancer patients' preferences and their physicians' perceptions.

PURPOSE: Shared decision making is a tenet of contemporary medicine and oncology practice. How involved elderly patients want to be in making treatment decisions and how physicians perceive patient preferences for such involvement are uncertain. PATIENTS AND METHODS: In structured interviews about multiple facets of chemotherapy treatment decision making, we asked patients age 70 years and older with a recent diagnosis of metastatic colorectal cancer (CRC) about their preferences for prognostic information and for involvement in treatment decision making. We also asked treating oncologists (n = 19) to describe their perceptions of patient preferences. Information and decision-making preferences were evaluated in relation to sociodemographic and clinical characteristics. RESULTS: Seventy-three patients age 70 to 89 years completed the study interview within 16 weeks of metastatic CRC diagnosis. Most patients (n = 70; 96%) had decided to receive chemotherapy and 61 had initiated treatment. Relatively few (n = 32; 44%) wanted information about expected survival when they made a treatment decision. Preference for prognostic information was more common among men than women (56% v 29%; P < .05). About half of the patients (n = 38; 52%) preferred a passive role in the treatment decision-making process. Physician perceptions were concordant with patient preferences for information in 44% of patient-physician pairs and for decision control in 41% of patient-physician pairs. CONCLUSION: For older patients with advanced CRC, preferences for prognostic information and for an active role in treatment decision making are not easily predictable. Physicians' perceptions are often inconsistent with patients' stated preferences. Explicit discussion of preferred decision-making styles may improve patient-physician encounters.