MECKEL-GRUBER-SYNDROME CONCOMITANT WITH DANDY-WALKER MALFORMATION - PRENATAL SONOGRAPHIC DIAGNOSIS IN 2 CASES

Meckel-Gruber syndrome is an autosomal recessive disorder which compri ses a characteristic triad of major abnormalities: renal cystic dyspla sia, occipital encephalocele, and postaxial polydactyly. Because of th e recessive inheritance, prenatal sonographic diagnosis is paramount f or informed genetic counselling of affected pregnancies. However, Meck el-Gruber syndrome may demonstrate variation in phenotypic expression when some malformations are different from those traditionally accepte d and cases may be evaluated as a different syndrome. The aim of this paper is to emphasise the phenotypic variability in Meckel-Gruber synd rome, and the importance of the prenatal sonography in the diagnosis. We also suggest that Dandy-Walker malformation or Dandy-Walker variant be accepted as one of the malformations which occur in the central ne rvous system as a part of the syndrome.