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

Abstract

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. ANKH 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 ANKH 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; ANKH:c.1122-4delCTC, p.Ser375del), which has already been described in patients with AD-CMD.