On the significance of craniosynostosis in a case of Kabuki syndrome with a concomitant KMT2D mutation and 3.2 Mbp de novo 10q22.3q23.1 deletion

Craniosynostosishas rarely been described in patients with Kabuki syndrome. We report here a boy with facial asymmetry due to combined premature synostosisof the right coronal and sagittal suturesas well as several symptoms reminiscentof Kabuki syndrome(KS). Our case supports previous observations and suggests that craniosynostosisis a part of the KS phenotype. The uniqueness of our case is the sporadic co-occurrenceof two genetic disorders, that is, a de novo frameshift variant in the KMT2D gene and a de novo 3.2 Mbp 10q22.3q23.1 deletion. Our findings emphasize the importance of the initial clinical assessment of children with craniosynostosisand that genomic and monogenicdisorders, such as Kabuki syndrome, should be considered among the differential diagnoses of syndromic forms of craniosynostosis.