Craniometaphyseal dysplasia with severe maxillary hypoplasia due to ANKH gene mutation: A case report

Craniometaphyseal dysplasia (CMD) is characterized by metaphyseal dysplasia, sclerosis of the skull base, and craniofacial bone overgrowth. The autosomal dominant form of CMD (OMIM: 123000) is associated with features such as mandibular prognathism, dental misalignment, and bony paranasal bossing. In contrast, the autosomal recessive form (OMIM: 218400) can result in severe distortion of the craniofacial structure, accompanied by complications such as cranial nerve compression, facial palsy, deafness, and visual impairment. Mutations causing CMD have been linked to the ANKH gene sequence variants. This case report describes a 11-year-old male diagnosed with CMD based on clinical and genetic findings. The patient presented with facial asymmetry, mandibular prognathism, delayed intellectual response, and gradual visual impairment, culminating in optic nerve compression and partial blindness. Radiographic evaluation revealed mixed dentition, thickened skull bones, cranial suture fusion, and Chiari I malformation. Biochemical analysis indicated hyperdense bone with normal serum calcium and phosphorus levels. Genetic testing confirmed an autosomal dominant pathogenic variant of a heterozygous nonframeshift deletion mutation of the ANKH gene (c.1124_1126del, p.Ser375del).