[Identification of a de novo interstitial 21q22.12q22.13 deletion in a patient with intellectual disability].

OBJECTIVE:To explore the genetic basis of a child featuring intellectual disability, developmental delay and epilepsy. METHODS:Cytogenetic and molecular analysis including chromosomal karyotyping analysis, single nucleotide polymorphism array (SNP array) and qPCR were performed. RESULTS:The karyotype of the child was determined as 46, XX; SNP array: arr [19]21q22.12q22.13(36 860 195-38 801 482)×1 dn. A heterozygous 1.9 Mb microdeletion was detected at 21q22.12q22.13. qPCR has confirmed deletion of exon 1 of the DYRK1A gene, which has occurred de novo. CONCLUSION:A 21q22 deletion was diagnosed with multiple genetic methods. Genotype-phenotype correlation suggested DYRK1A to be a candidate for intellectual disability.