Genetic analysis, ultrasound phenotype, and pregnancy outcomes of fetuses with Xp22.33 or Yp11.32 microdeletions.

ABSTRACT

OBJECTIVES: The phenotypes of Xp22.33 or Yp11.32 microdeletions comprising the short-stature homeobox (SHOX) gene have been extensively described in adults and children. Herein, the prenatal ultrasound phenotype and pregnancy outcomes of fetuses with Xp22.33/Yp11.32 microdeletions were analyzed to improve our understanding, diagnosis, and monitoring of this genetic condition in the fetal stage. METHODS: A total of 9,100 pregnant women referred to tertiary units for prenatal diagnosis were evaluated by chromosomal microarray analysis(CMA). RESULTS: Seven (0.08 %) fetuses had Xp22.33/Yp11.32 microdeletions, ranging from 243 kb to 1.1 Mb, that comprised SHOX. The ultrasonic phenotypes differed among these fetuses, with three fetuses presenting abnormal bone development, one had labial-palatal deformity and strawberry head, two had an abnormal ultrasonic soft marker, and one had no abnormalities. After genetic counseling, only one couple underwent pedigree assessment, which confirmed the paternal origin of the microdeletion. This infant presented delayed speech development, whereas other three infants showed a typical postnatal development. In three cases, the parents chose to terminate the pregnancy. CONCLUSIONS: The ultrasonic phenotype of fetuses with Xp22.33/Yp11.32 microdeletions resulting in SHOX heterozygosity loss is variable. Prenatal CMA can quickly and effectively diagnose Xp22.33/Yp11.32 microdeletions and SHOX loss, which may help prenatal counseling.