Abstract: Objective The clinical and molecular genetic characteristics of Kabuki syndrome (KS). Methods The clinical data of 2 children with KS who were treated with growth retardation was analyzed etrospectively. Using the nextgeneration sequencing technology, the children and their parents were sequenced with short stature-related genome or whole exome and whole genome copy number variation (CNV) detection. Results Two female children aged 36 months and 3 months old went to the doctor due to feeding difficulties and growth retardation. The clinical manifestations are special appearance, the length and weight Z scores for age are less than -2 . 5 , developmental delay, scoliosis, and abnormal head MRI. Case 1 has an ectopic right kidney, and case 2 has atrial septal defect. The results of genetic testing and analysis show KMT 2 D gene exon34 c. 10139 delA (p.K 3380 Sfs* 12 ) heterozygous mutation. KDM 6 A gene exon 16 c. 1909 - 1912 delTCTA (p.Ser 637 Thrfs* 53 ) heterozygous mutation. All are frameshift mutations. They are new and pathogenic mutations. Conclusions It is suggesting that children with growth retardation, feeding difficulties with growth retardation and special facial features should undergo genetic examination as soon as possible to confirm the diagnosis.

Key words: Kabuki syndrome genetic characteristics; KMT 2 D gene; KDM 6 A gene