Naga deficiency (Schindler disease, Kanzaki disease)

Introduction

3 types:

• type 1, Schindler disease (most severe form)
• type 2, Kanzaki disease (mild form)
• type 3, Schindler disease type 3 (intermediate form)

Genetics

• autosomal recessive
• associated with defects in NAGA

Clinical manifestations

• early (type 1) to late (type 2) onset
• neuroaxonal dystrophy & neurological signs
• convulsion during fever
• epilepsy
• psychomotor retardation
• hypotonia
• angiokeratoma corporis diffusum

Laboratory

• increased urinary excretion of glycopeptides & oligosaccharides containing alpha-N-acetylgalactosaminyl moieties
• alpha-galactosidase B in fibroblasts
• alpha-galactosidase B in leukocytes
• alpha-galactosidase B in dried blood spot
• alpha-galactosidase B in serum/plasma

More general terms

• carbohydrate inborn error of metabolism

Additional terms

• alpha-galactosidase B or alpha-N-acetylgalactosaminidase