FIRST-TRIMESTER SONOGRAPHIC DETECTION OF NEURODEVELOPMENTAL ABNORMALITIES IN SOME SINGLE-GENE DISORDERS

A number of single-gene disorders are detectable early in pregnancy th rough DNA analysis on chorionic villi. In some genetic disorders that are not yet amenable with this technique, prenatal diagnosis is based on the sonographic detection of neurodevelopmental abnormalities. In n ine fetuses at risk for the Meckel-Gruber, Walker-Warburg, and Joubert syndromes, sonographic scanning was accomplished in the first and ear ly second trimesters of pregnancy. In five out of nine fetuses, struct ural anomalies were detected. In two out of five affected fetuses, son ographic detection of a cephalocele was predated by the visualization of an enlarged rhombencephalon cavity diameter.