Segregation of HLA in families with oral clefts: evidence against linkage between isolated cleft palate and HLA.

In an earlier study of families with two or more sibs affected with a cleft of the lip with or without clefts of the palate, we found no evidence for close linkage of HLA with this malformation. In the present study, we confine our attention to isolated cleft palate, an entity that is genetically distinct from cleft palate associated with cleft lip. In 15 sibships with two or more affected sibs, cleft palate, and parental HLA haplotypes assorted independently in the affected sibs, providing evidence against close linkage of this phenotype.