Abstract: Objective To explore the clinical features and diagnosis of the type Ⅸ glycogen accumulation disease (phosphoglyceric acid kinase 1 deficiency) resulted from PGK 1 mutation. Methods Clinical traits, laboratory test results, and gene mutation screening by next-generation sequencing of a pediatric case with phosphoglyceric acid kinase 1 deficiency admitted to our hospital were retrospectively analyzed. Results A 3 years and 11 months old boy firstly came to our hospital for a sudden twitching onset, followed by rapid progression. He was attacked by recurrent twitching along with hemolytic anemia. During the third hospitalization, the boy developed the symptom of severe rhabdomyolysis, accompanied by obvious retardation of intelligence and motor developments. Genetic screening found a novel missense mutation (c.150 C>G, p.Cys 50 Trp) in PGK 1 which was inherited from his mother. According to ACMG guideline, the mutation can be classified as “likely pathogenic”. The boy was diagnosed with PGK 1 deficiency based on the clinical traits and genetic test results. Conclusion The phosphoglycerate kinase deficiency was a kind of rare X-linked recessive genetic disease caused by PGK 1 mutation, which can be confirmed by clinical features combing the result of PGK 1 gene mutation. To our knowledge, this mutation is first reported and meaningful for expanding the genetic mutation spectrum of PGK 1.

Key words: Phosphoglycerate kinase 1 deficiency; PGK 1 gene; gene mutation