Analysis of clinical and genetic characteristics of a child with ring chromosome 4 syndrome

OBJECTIVE To explore the genetic basis for a child featuring short stature. METHODS G-banded karyotyping, chromosomal microarray analysis (CMA) and high-throughput sequencing were carried out on peripheral blood sample from the child. RESULTS The karyotype of the child was ascertained as 45,XY,-4[3]/46,XY,r(4)(p16q35)[84]/47,XY,-4,r(4)(p16q25)*2[7]/48,XY,-4,r(4)(p16q35)*3[1]/46,XY,dic r(4;4)(p16q35;p16q35)[2]/46,XY,add(4)(p16)[3]. A 647 kb deletion at 4p16.3 was identified by CMA, which encompassed 6 OMIM genes including ZNF141, PIGG, PDE6B, ATP5I, PCGF3 and MYL5. High-throughput sequencing has identified no pathogenic/likely pathogenic variants consistent with the clinical symptoms. CONCLUSION A rare ring chromosome 4 syndrome was identified by combined chromosomal karyotyping, CMA and high-throughput sequencing. Conventional cytogenetic analysis and genetic testing in combine have enabled the diagnosis in this case.