RESUMO
ObjectiveTo discuss the diagnostic methods of global developmental delay caused by 10q24.3 heterozygous loss. MethodsA retrospective analysis was conducted on the clinical data of one child with global developmental delay， and the results of low depth whole-genome copy number variation sequencing （CNVseq） and family whole exome sequencing （WES） of the child and his parents. ResultsThe patient was a 10-month-old male with developmental retardation in four areas， with some special features （ocular hypertelorism， strabismus， flat nose bridge， protruding forehead， cleft palate， high palatal arch， etc.） and hypotonia of limbs. The CNVseq and WES test showed that the patient had new 10q24.3 heterozygosis loss. Because this region contains the gene SUFU associated with basal cell nevus syndrome and the gene CNNM2 associated with hypomagnesemia， seizures， and mental retardation， and the gene TRIM8 associated of Focal segmental glomerulosclerosis with neurodevelopmental syndrome， we speculated that the cause of the disease in the child was highly related to the heterozygosity deletion of SUFU gene and CNNM2 gene and TRIM8 gene. ConclusionGenetic testing should be improved as soon as possible for children with global developmental delay and special facial manifestations， so as to make clear diagnosis and to judge prognosis.