Abstract: Objective To analyze the clinical and molecular genetic characteristics of a patient with glycogen storage disease Ⅰb (GSDⅠb). Methods Clinical profile and laboratory data were collected. Genomic DNA was extracted from leukocytes of peripheral blood of the patient. All nine exons and the exon-intron boundaries of the SLC37A4 gene were amplified by PCR. The mutations were identified by bidirectional sequencing of the PCR products. Results The patient was diagnosed as GSDⅠb according to the clinical presentations and laboratory examinations, SLC37A4 mutation was identified as a homozygous C>T transition at nucleotide position 527 of the cDNA. The missense mutation is located in exon 3, at codon 191, changing proline to leucine, which changes the conformation of the glucose-6-phosphate translocase (G6PT). Conclusion Through SLC37A4 gene mutation analysis, the clinical diagnosis of GSDⅠb was confirmed. The alternation of G6PT structure caused by SLC37A4 gene mutation is the molecular genetic mechanism to explain clinical manifestation of the patient. To our knowledge, this is the first report of P191L as a cause of GSD1b in Han China mainland. In the future, GSDⅠb could be diagnosed through genomic DNA mutation analysis.

Key words: glycogen storage disease Ⅰb, glucose-6-phosphate translocase, SLC37A4, mutation