Immunodeficiency due to a unique protracted developmental delay in the B-cell lineage

A unique immune deficiency in a 24-month-old male characterized by a transi ent but protracted developmental delay in the B-cell lineage is reported. S ignificant deficiencies in the number of B cells in the blood, the concentr ations of immunoglobulins in the serum, and the titers of antibodies to T-d ependent and T-independent antigens resolved spontaneously by the age of 39 months in a sequence that duplicated the normal development of the B-cell lineage: blood B cells followed by immunoglobulin M (IgM), IgG, IgA, and sp ecific IgG antibodies to T-independent antigens (pneumococcal polysaccharid es). Because of the sequence of recovery, the disorder could have been conf used with other defects in humoral immunity, depending on when in the cours e of disease immunologic studies were conducted. Investigations of X-chromo some polymorphisms suggested that the disorder was not X linked in that the mother appeared to have identical X chromosomes. An autosomal recessive di sorder involving a gene that controls B-cell development and maturation see ms more likely. In summary, this case appears to be a novel protracted dela y in the development of the B-cell lineage, possibly due to an autosomal re cessive genetic defect.