Osteopenia / Fractures
STAT3 Deficiency (Hyper IgE syndrome) - Patients have osteopenia and pathologic fractures. Other musculoskeletal abnormalities include joint hypermobility, scoliosis, and retained primary teeth. Of note, these musculoskeletal abnormalities are not features of DOCK8 deficiency.
X-linked hyper IgM Syndrome - Patients can develop osteopenia and increased fractures. A regulatory role for CD40L in bone mineralization through T cell priming and RANKL signaling has been reported.
Shwachman-Diamond Syndrome - Patients develop bone marrow failure (with neutropenia), pancreatic insufficiency, and metaphyseal chondrodysplasia. Other skeletal abnormalities include short stature and osteopenia.