Congenital Neutropenia (HAX1-Related) (HAX1)
Congenital neutropenia (HAX1-related) is an autosomal recessive disorder caused by pathogenic variants in the gene HAX1, which has an increased incidence in Asia and the Middle East. This disorder is characterized by bone marrow failure with reduced neutrophils, presenting in infancy. Patients have multiple bacterial and fungal infections and are at risk for developing acute myeloid leukemia or myelodysplastic syndrome. Some patients develop neurological symptoms, such as psychomotor retardation and/or seizures. Life expectancy may be reduced due to sepsis or malignancy. A genotype-phenotype correlation has been proposed where pathogenic variants that affect only one of the two HAX1 isoforms may result in neutropenia without neurological symptoms.
For information about carrier frequency and residual risk, please see the residual risk table.