Imprinting Status of IGF2 in Cord Blood Cells of Han Chinese Newborns

Loss of imprinting (LOI) of insulin-like growth factor II gene (IGF2) is an epigenetic abnormality associated with human diseases. However, little is known about the characteristics of IGF2 imprinting in newborn cord blood cells. METHODS: A total of 923 cord blood samples from term singletons and related clinical data were collected; IGF2 imprinting status in 273 specimens were successfully analyzed using RT-PCR and restriction fragment length polymorphism. RESULTS: LOI of IGF2 was detected in 20.9% of informative samples. The mean birth weights (BW) in the LOI and the normal imprinting groups were 3462.7 ± 460.2 g and 3363.7 ± 427.7 g, respectively. The abdominal perimeters in the LOI group tended to be larger than that in the normal imprinting group. Pregnancy complications, delivery modes, newborn diseases, occurrences of malignant tumors in grandparents, and other maternal factors were not associated with LOI of IGF2. 22.2% of the infants with IGF2 LOI also showed LOI in their father’s lymphocytes while 21.4% in their mother’s lymphocytes. CONCLUSIONS: About 20% of Han Chinese newborns indicated LOI of IGF2 in their cord blood lymphocytes that may represent the epigenetic characteristics in this ethnic group. While IGF2 LOI tends to be weakly inherited between parents and offspring, abnormal imprinting seems to be statistically unrelated with phenotypes of newborns, although it might have an association with later phenotypes of infants.