TABLE 2.

Inborn errors of metabolism associated with neutropenia

Disorder	Clinical features	Infections and causes
α-Mannosidosis	Dysostosis multiplex, hepatomegaly, facial coarsening, developmental delay	Recurrent bacterial infections due to neutrophil chemotaxis defect
Glycogen storage disease 1b/c	Hepatomegaly, hypoglycemia, seizures	Recurrent mucous membrane ulcers, recurrent infections due to neutropenia and neutrophil dysfunction
Transcobalamin II deficiency	FTT,a vomiting, megaloblastic anemia, increasing neurologic dysfunction	Oral ulcers, frequent infections; pancytopenia and hypogammaglobulinemia
Branched-chain organic acidurias	16 types with variable clinical features; typically include acidosis, neurologic signs, and cardiomyopathy; may present with a Reye's-like syndrome	Accumulation of toxic metabolites diminishes leukocyte function; 3-methylglutaconic aciduria type II (Barth syndrome) is associated with neutropenia

^aFTT, failure to thrive.