NOSOLOGY OF FETAL HYPOKINESIA SEQUENCE BASED ON CNS ABNORMALITIES - IS THERE AN AASE-SMITH SYNDROME

Aase-Smith syndrome (ASS) is usually defined as a dominantly inherited combination of arthrogryposis, Dandy-Walker malformation and cleft pa late. We describe a sporadic case of foetal akinesia with abnormal fos sa posterior, fitting the diagnosis of ASS, and discuss the nosology o f this entity among syndromes with distal arthrogryposis. ASS shows a ''hybrid'' phenotype: adults with mild ASS could be classified as dist al arthrogryposis, whereas severely affected newborns overlap with the Marden-Walker phenotype, which is recessively inherited. The specific ity of the disorder comes from the coexistence of both forms in the sa me pedigree, so that ASS appears impossible to diagnose with certitude in sporadic cases. We suggest that the severe expression of ASS is on ly the extreme but aspecific expression of a dominantly inherited form of distal arthrogryposis. Implications for genetic counselling in dis tal arthrogryposis are outlined.