[Kleefstra syndrome 1 and ring chromosome 9 in a case].

ABSTRACT

OBJECTIVE: To analyze the clinical and molecular genetic characteristics of patient with Kleefstra syndrome 1. METHODS: Clinical data, chromosomal karyotype and whole genome copy number variations (CNVs) of the patient were analyzed. RESULTS: The patient was found to have a karyotype of 45,XX,-9[4]/46,XX,r(9)(p24q34)[56]. Whole-genome CNVs detection revealed that she has carried a heterozygous deletion of approximately 670 kb at 9q34.3, which encompassed the entire EHMT1 gene. The region is strongly associated with Kleefstra syndrome (1/9q telomere deletion). In addition, the patient also had heterozygous deletion of 9pter, which may predispose to formation of ring chromosome 9. CONCLUSION: The child was diagnosed with Kleefstra syndrome type 1 in conjunct with ring chromosome 9.