Genotyping with DNA probes in combined immunodeficiency syndrome with defective expression of HLA

We performed HLA genotyping by using restriction-enzyme fragments hybridized with specific HLA probes instead of traditional immunologic methods in two patients whose lymphocytes expressed so few HLA antigens on the cell surface that serologic methods failed. Segregation of restriction-fragment-length polymorphism permitted identification of the genotypes. In addition, known correlations between serologically determined antigens and restriction-fragment-length polymorphism were confirmed. We applied this approach in making therapeutic decisions regarding bone marrow transplantation.