Ehlers-Danlos syndrome versus cleidocranial dysplasia

Dear Sir, The early identification of hereditary syndromes is essential for planning medical and surgical interventions for reducing the risk of complications [1]. Unfortunately, clinical phenotypes of hereditary syndromes in the first years of life and in mild cases are often poorly characterized. Some disease symptoms are also common to several different genetic conditions. Cleidocranial dysplasia (CCD, OMIM #119600) is a genetic condition that predominantly affects the skeletal system. Typical CCD features include persistently open skull sutures, clavicular hypoplasia/aplasia, and dental anomalies [2,3]. CCD is caused by a heterozygous loss-of-function mutation in the RUNX2 gene [2,3]. However, the abnormal shoulder and arm mobility commonly observed in CCD is also typical of other syndromes, particularly hypermobile Ehlers-Danlos syndrome (EDS-HT). EDS-HT is marked by joint laxity with minimal skin changes and no skin fragility [4] but does not have additional specific clinical features and cannot be diagnosed through laboratory tests. The child characterized in this report was initially misdiagnosed with EDS-HT when the correct diagnosis was CCD. CCD was confirmed by genetic findings but not until several years later. The male proband was the second child born to healthy, non-consanguineous Caucasian parents. The family history was unremarkable and did not indicate a history of mental retardation, genetic diseases, or birth defects. The child was born at 35 weeks of gestational age as the result of a premature membrane rupture after an uneventful pregnancy. At birth, he weighed 2,700 gr and had a body length of 45.5 cm, occipital frontal diameter of 30 cm, and an APGAR score of 9/10. The patient’s medical history after reaching school age was unremarkable, and he had normal body and