Male or female patient with isolated chronic neutropenia, defined as absolute neutrophile count (ANC)<0.5X10³/ml on at least 3 determinations over a period of 6 months, without cycling of ANC, and associated with one of the following:

1. Mutation in of the ELA2 gene
2. Mutation of the Gfi1 gene
3. avtivating mutation of the WASP gene

Isolated SCN can be inherited as an AD, AR (less common) or X-linked trait. Many cases represent sporadic presentations due to de novo mutations. The low ANC predispose to recurrent and severe infections since infancy. Infections are mainly bacterial of fungal. No other haematological abnormalities (anemia, thrombocytopenia) are present. Patients with isolated SCN are at high risk for myelodysplasia and acute myeloid leukaemia. Most patients respond to treatment with recombinant G-CSF, 3-5% fail to respond. A high incidence of sepsis and of myeloid transformation in patients on long treatment with high dose rhG-CSF.

1. Shwachman-Bodian-Diamond syndrome
2. Hermansky-Pudlak type 2 syndrome
3. Barth syndrome
4. Glycogenosis type 1b
5. WHIM syndrome
6. chronic neutropenia in reticular dysgenesis, SCID with maternal T-cell engraftment, CD40L deficiency, CD40 deficiency
7. transient neutropenia during infections (as in XLA)
8. autoimmune neutropenia in patients with common variable immunodeficiency or with autoimmune lymphoproliferative syndrome