ABSTRACT

Objective: To investigate the morbidity and distribution of 35 inherited metabolic diseases in high risk children by LC-MS/MS in northern China.

Methods: The dry blood on filter papers, collected from 2760 children clinically suspected to have inherited metabolic diseases from more than sixty hospitals in north China, was tested by LC-MS/MS. The specimen was extracted out of the dry blood on filter paper, derivatized before being injected into LC-MS/MS. The LC-MS/MS methodology used in the study was transferred from Pediatrix Medical Group (1301 Concord Terrace, Sunrise, FL 33323), validated in our lab and further compared with United States CDC standard. The positive results were further confirmed by gas chromatography-mass, other laboratory tests and clinical symptoms.

Results: 249 of the 2760 children (9%) were diagnosed with one or more of twenty-one disorders. Out of 249 patients, there are 41 (16.5%) fatty acid disorders, 71 (28.5%) amino acid diseases, and 137 (55%) organic acidemias. 48 of the 249 patients (19.3%) were neonates, including 11 (22.9%) with fatty acid disorders, 15 (31.3%) with amino acid diseases, and 22 (45.8%) with organic acidemias. 201 of the 249 patients were elder than 28 days, and was composed of 30 (14.9%) with fatty acid disorders, 56 (27.9%) with amino acid diseases, 115 (57.2%) with organic acidemias.

Conclusions: The LC-MS/MS technology can be used to detect over 30 inherited metabolic disorders for Chinese pediatric clinic in a single collection of blood. The morbidity of IMD (9%) is relatively high among high risk children, thus we highly suggest that we shall provide initial screening of over 30 IMDs for the high risk children in China using the technology of LC-MS/MS.