Highlighting the importance of X-ray diagnostics for targeted molecular genetic analysis in the diagnosis of rare autosomal dominant craniometaphyseal dysplasia

Autosomal dominant craniometaphyseal dysplasia (AD-CMD) is a rare condition defined by the occurrence of progressive diffuse hyperostosis of cranial bones and abnormal metaphyseal widening of the tubular bones. <i>ANKH</i> is known to be the only gene associated with AD-CMD. We present a case of a toddler boy with macrodolichocephaly, asymmetry of the skull, wide bulging forehead, gingival hypertrophy and irregular teeth. Physical examination, X-ray and DNA analysis were performed. All exons and flanking intron regions of <i>ANKH</i> were amplified by PCR and directly sequenced using the Sanger method. X-ray images showed diffuse osteosclerosis in the area of facial skeleton and skull base. Limbs exhibited club-shaped enlargement of the distal metaphysis of the femur and the proximal metaphysis of the tibia were described. The DNA analysis showed that the patient is a heterozygous carrier of the known pathogenic in-frame deletion (rs121908406; <i>ANKH</i>:c.1122-4delCTC, p.Ser375del), which has already been described in patients with AD-CMD.