A new case of alpha-N-acetylgalactosaminidase deficiency with angiokeratoma corporis diffusum, with Meniere's syndrome and without mental retardation

alpha -N-acetylgalactosaminidase (alpha -NAGA) deficiency is a rare heredit ary lysosomal storage disease, and only three alpha -NAGA-deficient patient s with angiokeratoma corporis diffusum (Kanzaki) have been described. We re port a further case in a 47-year-old Japanese woman, the product of a consa nguineous marriage. The remarkable findings in this patient were her normal intelligence, Meniere's syndrome, disturbance of peripheral sensory nerves , hearing loss and cardiac hypertrophy alpha -NAGA enzyme activity in her p lasma was 0.77% of the normal value. Other enzyme activities, such as alpha -galactosidase, beta -galactosidase, alpha -L-fucosidase, beta -mannosidas e and aspartylglucosaminidase, were within normal limits. A large quantity of amino acid O-glycans was detected in her urine. Gene analysis revealed a novel point mutation (G-->A transition) at nucleotide 11018 (986 in the cD NA) resulting in an Arg-329-Gln substitution. Kanzaki disease has the same enzyme defect as Schindler disease, but the manifestations are quite differ ent.