RESUMO
OBJECTIVE: To investigate the possibility that neuroepithelial tumors in Turcot's syndrome are caused by pleiotropic mutations in the gene for adenomatous polyposis coli (APC), a tumor-suppressor gene implicated in colonic cancer. METHODS: We studied the inheritance patterns of genetic markers for the chromosome 5q21 region in 12 members of a Turcot's syndrome kindred with five affected members. We performed linkage analysis to detect linkage between the disease phenotype and DNA markers. RESULTS: Marker D5S346, located 30 to 70 kilobases from the APC locus, showed evidence highly suggestive of linkage to the disease phenotype (lod score = 1.92). CONCLUSIONS: The data provide evidence that the tumor-suppressor gene implicated in APC and sporadic colon cancers may also cause malignant neuroepithelial tumors in Turcot's syndrome.
Assuntos
Polipose Adenomatosa do Colo/genética , Ligação Genética , Mutação , Tumores Neuroectodérmicos Primitivos Periféricos/genética , Síndrome de Gardner/genética , Marcadores Genéticos , Humanos , Linhagem , SíndromeRESUMO
First-trimester fetal biometry using transvaginal sonography is now feasible and desirable due to improved imaging and probe maneuverability. A study of 144 early normal pregnancies with precise dates is presented. Regression models were constructed for the crown-rump length, biparietal diameter, head circumference and abdominal circumference. Error analysis of the technique and calculations was performed. First-trimester fetal biometry may be used for obtaining precise estimates of gestational age and may help to detect early fetal maldevelopment resulting in abnormal growth.
