A Rare Cause of Congenital Neutropenia: SRP54 Variant

Severe congenital neutropenia (SCN) is a heterogeneous disease characterized by maturation arrest in the granulopoiesis stage of the myelocytic lineage, accompanied by early-onset bacterial infections. Absolute neutrophil count in the peripheral blood in SCN patients is typically below 500/mm3. In humans, the signal recognition particle (SRP) complex consists of six proteins located on the 7S ribonucleoprotein (RNA) molecule. The signal recognition particle 54 (SRP54) protein forms the basic element of this complex with its guanosine triphosphatase (GTPase) activity, regulating this whole physiological process. This case report features a three-year-old girl with isolated severe congenital neutropenia with a heterozygous mutation in the SRP54 gene.