We report on four individuals in one kindred with relative or absolute short stature; increased upper/lower segment ratio with decreased arm span; mandibular prognathism and dental abnormalities; fractures following minimal trauma; mild to moderate anemia with extramedullary hematopoiesis; and radiographic changes of osteopetrosis, including sclerosis of the cranial base, generally increased bone density, sclerosis of the vertebral end plates, and transverse bands and poor diaphyseal modelling of the long bones.