Aspartylglucosaminuria. Aspartylglucosaminidase deficiency
Incidence
AR disease. It is a lysosomal enzyme deficiency. Most patients are reported from Finland with more than 200 patients by 1993. Can be seen in other countries, with 40 cases reported. The gene is located in chromosome X.
Clinical Characteristics
Children are mentally retarded from early childhood, having delayed speech or never developing speech. There are severe behavioral abnormalities with alternating hyperactivity and apathy. Psychotic symptoms are possible. Progressive mental regression slowly occur between ages 6 and 15 years. Motor clumsiness, mild pyramidal signs. Seizures may occur. Also failure to thrive, joint laxity, brachicephaly. The condition has a protracted course. Patients may reach adulthood. There are mild coarsening of the face. Mild dysostosis multiplex and mild cataracts.. There are some photosensitive and acne of skin. Patiens may have mitral valve insuficiency with heart murmur. Crystal-like lens opacity seen in some patients. There are subtle non neurological symptoms with gargoil-like appearance after age 10 years. Minimal skeletal changes similar to Hurler syndrome. Hepatomegaly and abdominal hernia may occur but rare. There is no splenomegaly. CSF is normal and EEG is non specific. Vacuolated lymphocytes in blood. There is neutropenia. Patients excrete large amounts of aspartylglucosamine in urine detected by thin layer chromatography or TLC (same test done to test aminoacids in urine).
Precipitants
no
Provocation Tests
no
Diagnostic Procedures
EB-F, EB-W. Patients excrete large amounts of aspartylglucosamine in urine detected by thin layer chromatography or TLC (same test done to test aminoacids in urine).