[2] This disorder was discovered in two unrelated Israeli boys 3 and 5 years of age, each the offspring of consanguineous parents.

Both had severe mental retardation, short stature, a distinctive facial appearance, and the Bombay (hh) blood phenotype, and both were secretor- and Lewis-negative.

They both had had recurrent severe bacterial infections similar to those seen in patients with LAD1, including pneumonia, periodontitis, otitis media, and localized cellulitis.

Similar to that in patients with LAD1, their infections were accompanied by pronounced leukocytosis (30,000 to 150,000/mm3) but an absence of pus formation at sites of recurrent cellulitis.

Because the genes for the red blood cell H antigen and for the secretor status encode for distinct α1,2-fucosyltransferases and the synthesis of Sialyl-LewisX requires an α1,3-fucosyltransferase, it was postulated that a general defect in fucose metabolism is the basis for this disorder.