X-linked hyper IgM syndrome: a novel sequence variant associated with an atypical mild phenotype.
X-linked hyper IgM syndrome is associated with abnormalities in the gene encoding CD40 ligand (CD40LG). A typical phenotype evolves during infancy in affected males. This phenotype includes neutropenia, dysgammaglobulinemia, bacterial sinopulmonary infections, and opportunistic infections. In the absence of the typical phenotypic features, clinicians must maintain a high level of suspicion for X-linked hyper IgM syndrome. We describe a unique hemizygous CD40LG mutation which was discovered in a 12-year-old boy with chronic severe neutropenia, a normal IgG level, and absence of sinopulmonary or opportunistic infections. The clinical implications of this mutation and associated atypical phenotype are discussed.
Division of Hematology, CHOC Children's Hospital, Orange, CA 92868, USA. dbuchbinder@choc.org
David
D
Buchbinder
Sang
S
Park
Diane
D
Nugent
D023201:CD40 Ligand / Q000235:genetics*; D002648:Child; D006801:Humans; D053307:Hyper-IgM Immunodeficiency Syndrome, Type 1 / Q000235:genetics*; D008297:Male; D009154:Mutation; D009503:Neutropenia / Q000209:etiology; D010641:Phenotype
D023201:CD40 Ligand