[Clinical and genetic analysis of a fetus with 17q12 microdeletion syndrome].

OBJECTIVE

To explore the clinical phenotype and genetic characteristics of a fetus with 17q12 microdeletion syndrome.

METHODS

A fetus with 17q12 microdeletion syndrome who was diagnosed at Huzhou Maternal & Child Health Care Hospital in June 2020 was selected as the study subject. Clinical data of the fetus was collected. The fetus was subjected to chromosomal karyotyping and chromosomal microarray analysis (CMA). To determine the origin of fetal chromosomal abnormality, its parents were also subjected to CMA assay. The postnatal phenotype of the fetus was also investigated.

RESULTS

Prenatal ultrasound revealed polyhydramnios and fetal renal dysplasia. The fetus was found to have a normal chromosomal karyotype. CMA has detected a 1.9 Mb deletion in the 17q12 region, which has encompassed five OMIM genes including HNF1B, ACACA, ZNHIT3, CCL3L1 and PIGW. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the 17q12 microdeletion was predicted as pathogenic copy number variation (CNV). CMA analysis has detected no pathogenic CNV in both parents. After birth, the child was found to have renal cysts and abnormal brain structure. Combined with the prenatal findings, the child was diagnosed with 17q12 microdeletion syndrome.

CONCLUSION

The fetus has 17q12 microdeletion syndrome presenting as abnormalities of the kidney and central nervous system, which are strongly correlated with functional defects of the deletion region involving the HNF1B and other pathogenic genes.