BACKGROUND: Spondyloepimetaphyseal dysplasias (SEMD) are a large group of skeletal disorders represented by abnormalities of vertebrae in addition to epiphyseal and metaphyseal areas of bones. Several genes have been identified underlying different forms. ACAN gene mutations were found to cause Aggrecan-related bone disorders (spondyloepimetaphyseal dysplasias,spondyloepiphyseal dysplasias, familial osteochondritis dissecans and short stature syndromes). This study aims to find the disease causing variant in Egyptian patient with SEMD using whole exome sequencing.
METHODS: Whole-exome sequencing was performed for an Egyptian male patient who presented with short stature, clinical and radiological features suggestive of unclassified SEMD.
RESULTS: The study identified a novel de novo heterozygous ACAN gene variant (c.7378G>A; p.Gly2460Arg) in G3 domain. Mutations in ACAN gene have been more commonly associated with short stature than SEMD. The phenotype of our patient was intermediate in severity between spondyloepiphyseal dysplasia presentation; Kimberley type(SEDK) and Spondyloepimetaphyseal dysplasias Aggrecan (SEMDAG) CONCLUSIONS: Whole exome sequencing revealed a novel de novo ACAN gene variant in patient with SEDK. The clinical and skeletal phenotype of our patient was much severe than those reported originally and showed more metaphyseal involvement. To the best of our knowledge, two previous studies reported a heterozygous variant in ACAN with spondyloepiphyseal dysplasia presentation; Kimberley type.

Cleidocranial dysplasia (CCD), also known as Marie-Sainton syndrome, is a rare disorder of autosomal dominant type that presents specific characteristics at the skeletal and dental level. The diagnosis of CCD is based on clinical and radiographic findings. Panoramic, cephalometric and anterior poster radiographs have been used for its diagnosis in dentistry. However, these radiological techniques have limitations, and advances in technology with new imaging studies such as magnetic resonance imaging (MRI) and ultrasound have emerged, contributing to the diagnosis of CCD. Therefore, the aim of this review was to identify and describe current imaging studies that contribute to both the diagnosis and adequate and efficient treatment planning of CCD, and describe the clinical and radiographic characteristics of patients with this syndrome.
La displasia cleidocraneal (DCC), también conocida como síndrome de Marie-Sainton, es un trastorno poco común de tipo autosómico dominante, que presenta características específicas a nivel esquelético y dental. El diagnóstico de DCC se basa en hallazgos clínicos y radiográficos. Las radiografías panorámicas, cefalométricas y posteroanteriores se han utilizado para su diagnóstico en el área de la odontología, pero con los avances de la tecnología y debido a las limitaciones de estas técnicas radiológicas han surgido nuevos estudios de imagen como la resonancia magnética (RM) y la ecografía, que contribuyen al diagnóstico de DCC. Por lo tanto, el propósito de esta revisión fue identificar y describir los estudios de imagen actuales que aportan tanto al diagnóstico como a la planificación del tratamiento adecuado y eficiente de la DCC, y permiten describir las características clínicas y radiográficas de los pacientes con este síndrome.

Progressive pseudorheumatoid dysplasia (PPD) is a rare disorder of postnatal skeletal and cartilage development that often presents with similar clinical findings to juvenile idiopathic arthritis. Patients with PPD display findings of progressive cartilage loss and secondary osteoarthritis over serial imaging studies and have an absence of elevation of inflammatory markers. Awareness of the imaging features of PPD on radiographs and magnetic resonance imaging (MRI) may be important for early diagnosis and surveillance of the disease.