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

Abstract

Loss of imprinting (LOI) of insulin-like growth factor II gene (IGF2) is anepigenetic abnormality associated with human diseases. However, little is known about thecharacteristics of IGF2 imprinting in newborn cord blood cells. METHODS: A total of 923cord blood samples from term singletons and related clinical data were collected; IGF2imprinting status in 273 specimens were successfully analyzed using RT-PCR andrestriction 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 imprintinggroups were 3462.7 ± 460.2 g and 3363.7 ± 427.7 g, respectively. The abdominal perimetersin the LOI group tended to be larger than that in the normal imprinting group. Pregnancycomplications, delivery modes, newborn diseases, occurrences of malignant tumors ingrandparents, and other maternal factors were not associated with LOI of IGF2. 22.2% ofthe infants with IGF2 LOI also showed LOI in their father’s lymphocytes while 21.4% intheir mother’s lymphocytes. CONCLUSIONS: About 20% of Han Chinese newbornsindicated LOI of IGF2 in their cord blood lymphocytes that may represent the epigeneticcharacteristics 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.

Keywords

• IGF2
• genomic imprinting
• cord blood
• birth weight
• Han Chinese