LACK OF LINKAGE DISEQUILIBRIUM BETWEEN TRANSFORMING-GROWTH-FACTOR-ALPHA TAG-I POLYMORPHISM AND CLEFT-LIP WITH OR WITHOUT CLEFT-PALATE IN FAMILIES FROM NORTHEASTERN ITALY

Cleft lip with or without cleft palate (CL +/- P) is the most frequent craniofacial malformation in different human populations and its caus e is largely unknown, Several studies based on population associations have suggested that an allele mapping in the transforming growth fact or alpha locus could be responsible, as a risk factor, for the develop ment of the defect. Our investigation of the Tag I polymorphism at the transforming growth factor alpha locus, performed in 40 CL +/- P fami lies, did not find evidence for linkage disequilibrium with particular alleles. Moreover, tight linkage was excluded with the traditional LO D score method, (C) 1998 Wiley-Liss, Inc.