GENETIC-HETEROGENEITY OF MECKEL-SYNDROME

Meckel syndrome (MKS) is a lethal, autosomal recessive condition chara cterised by an occipital meningo encephalocele, enlarged kidneys with multicystic dysplasia, fibrotic changes of the liver in the portal are a with ductal proliferation, and postaxial polydactyly. Recently, a MK S gene has been mapped to chromosome 17q21-q24 in Finnish families, wi th no evidence of locus heterogeneity in this population. Here, we rep ort the exclusion of chromosome 17q21-q24 in eight typical MKS familie s of North African and Middle Eastern ancestry and provide evidence fo r genetic heterogeneity of this condition.