BACKGROUND
Cleidocranial dysplasia (CCD) is a rare (1: 1 000 000) autosomal dominant congenital skeletal dysplasia characterized by widely patent calvarial sutures, clavicular hypoplasia, supernumerary teeth, and short stature. Only a minority of the cases are diagnosed early after birth. We present another case of proven CCD presenting with typical neonatal phenotype to promote awareness of this rare disorder.
CASE REPORT
A male term neonate presented clinically with unusual soft skull, extremely large fontanels, and palpable right clavicular discontinuity. Cranial computed tomography revealed severe calvarian ossification defect leading to widely enlarged sutures. Right-sided clavicular dysplasia with discontinuity in the middle part were shown on a chest X-ray. Whole-exome sequencing and Sanger sequencing of the RUNX2 gene confirmed the diagnosis of CCD following a single-nucleotide mutation (NM_001024630.3: c.569G>A) in the child as well as in his mother. His additional family members in the maternal line had also different degrees of clavicular and cranial hypoplasia or multiple dental anomalies.
CONCLUSIONS
In clinical practice, in a newborn presenting with severe defects in ossification of the skull and widely enlarged sutures and/or hypoplasia or aplasia of the clavicles, CCD should be considered based on a combination of clinical and radiological genetic criteria. Family history and genetic testing are crucial since the mutation follows autosomal dominant inheritance.

Keywords: Cleidocranial Dysplasia; Neonatology