Ultrasonographic findings and prenatal diagnosis of complete trisomy 17p syndrome: A case report and review of the literature.

BACKGROUND: Trisomy of the short arm of chromosome 17 is a rare genomic disorder. The clinical features of complete trisomy 17p syndrome have been described. Most cases of this syndrome have been found in infants and children, but only a few cases were found by ultrasound in the prenatal period.

METHODS: We report a case of complete trisomy 17p syndrome, which was inherited from paternal balanced translocation t(15;17)(q11.2;q11.2). A pregnant woman underwent an ultrasound examination at 24 weeks of gestation. Amniotic fluid was collected by amniocentesis. Cytogenetic and single nucleotide polymorphism array analyses were performed. We further reviewed the relationship between duplication regions and the clinical phenotype.

RESULTS: Ultrasonographic evaluation showed intrauterine growth retardation and a right choroid plexus cyst, but the gallbladder was not observed. The fetal karyotype was 46,XX,der(17)t(15;17)(q11.2;q11.2)pat. The father's karyotype was 46,XY,t(15;17)(q11.2;q11.2). The single nucleotide polymorphism array results showed arr[GRCh37] 17p13.3q11.1(525-25309337)×3, which indicated a 25.309-Mb duplication.

CONCLUSION: Complete trisomy 17p syndrome shows severe malformations. Intrauterine growth retardation is the most typical manifestation of this syndrome as shown by ultrasonography in the second trimester of pregnancy. The genotype-phenotype relationships of complete trisomy 17p syndrome are not completely consistent. To further determine these relationships, additional cases are necessary to provide more information from ultrasonographic findings during pregnancy.