[Genetic analysis of a child with cleidocranial dysplasia and 6q21-q22.31 microdeletion].

Objective To carry out genetic analysis on a child with developmental delay and multiple malformation. Methods The karotypes of the child and her parents were analyzed with routine chromosomal G-banding. Their genomic DNA was analyzed with array comparative genomic hybridization (aCGH). Results The karyotype of the proband was determined as 46, XX, del(6)(q22), inv(6)(p21.1q21), while no karyotypic abnormality was detected in her parents. aCGH has identified in the child a de novo 800 kb deletion encompassing the RUNX2 gene at 6p21.1 and a de novo 11.79 Mb deletion at 6q21-q22.31. Conclusion Both of the de novo deletions are pathogenic. Deletion of the RUNX2 gene probably underlies the cleidocranial dysplasia in the patient, while the 6q21-q22.31 deletion may result in malformation of the brain. Key words: Cleidocranial dysplasia; RUNX2 gene; Array comparative genomic hybridization