Glycogenosis Type 1B, also called glycogen storage disease type 1B, is a type of glycogenosis due to Glucose 6-phosphate deficiency. The disease is caused by a dysfunction of the G6P system, a key in glucose regulation step. The cause is the presence of mutations in the gene SLC37A4 (11q23), which causes a deficit of translocase G6-P protein. Its transmission is autosomic recessive. The prevalence is unknown but the annual incidence at birth is approximately 1/100,000. Type 1B is the less frequent type, affecting about 20% of patients.
The clinical picture is similar to glycogenosis due to G6P deficiency type 1A, but also neutropenia and neutrophil dysfunction, responsible for a tendency towards infections, recurrent aphthous gingivostomatitis and inflammatory bowel disease.
Management is similar in both types of glucogenosis. However, in type 1B, periodic antibiotic therapy may be necessary, as well as the administration of granulocyte colony stimulating factor, which allows for correction of neutropenia, reducing infections and inflammatory bowel disease.