Immune defects in subjects with dysmorphic disorders

Patients with dysmorphic disorders seem to have frequent respiratory infections that may be attributed to associated anatomic or neurological abnormalities, but immune defects may contribute to their susceptibility to infections. We screened subjects with dysmorphic conditions for major hematologic, B-cell and T-cell defects. We studied 84 subjects with dysmorphic disorders: 29 with chromosomal disorders, 27 with single gene disorders, and 28 with unclassified dysmorphic disorders. They were evaluated by physical examination; medical history suggestive of possible immune deficiency; complete blood count; serum immunoglobulin G (IgG), IgA, and IgM levels; and lymphocyte subsets. Low laboratory values (less than fifth percentile for age) were detected in 54.8%; was highest in the chromosomal disorder group (79.3%) followed by the single gene disorder group (55.6%) and was lowest in the unclassified dysmorphic disorder group (28.6%). The most common low values were in the CD19 and CD16/56 lymphocyte subpopulations followed by IgG and IgA levels. None of the subjects had neutropenia or thrombocytopenia. History of significant recurrent infections was noted in five subjects, all of whom had abnormal laboratory values. The highest frequency of abnormal laboratory values was in Down syndrome followed by Turner syndrome and chromosome deletions. We concluded that patients with dysmorphic disorders, particularly those with chromosomal disorders, have a high frequency of various B-cell and T-cell defects that may be contributing to their susceptibility to infection. Studies are needed to further delineate the immunologic defects in that population and to investigate a possible genetic basis at the molecular level.