Differential diagnosis of microcephalic osteodysplastic primordial dwarfism (MOPD).

Purpose: While the rare Seckel-Syndrome is defined by clear criteria, clini cal and radiologic findings for microcephalic osteodysplastic primordial dw arfism (MOPD) make an exact diagnosis and classification difficult. By comp aring our patients to previously described cases of MOPD we evaluate the hy pothesis that this disorder has a greater heterogeneity than has been belie ved up until now. Furthermore the differential diagnosis of the MOPD-comple x is discussed. Results: Two cases that show typical growth retardation, mi crocephalus and facial anomalies as well as osteodysplastic deformities inc luding hip dysplasia are presented. The parents of both children are consan guineous and of Arabic race. In one of the children growth homone levels we re noticeably decreased. In discrepancy to the Seckel-syndrome both childre n showed no signs of mental retardation, therefore the classification into the heterogeneous group of microcephalic osteodysplastic primordial dwarfis m (MOPD) is the most likely diagnosis. Conclusion: It is suggested that mic rocephalic osteodysplastic primordial dwarfism (MOPD) has a greater clinica l and radiological expression than has been assumed up until now. Whether o ur results are merely a variant or suggest a new subtype of the MOPD can on ly be resolved by further cases. The exact pathogenesis of the disease curr ently remains unknown but the most probable cause is an autosomal recessive inheritance.