Molecular markers of predictive value associated with low birth weight

Sub-optimal fetal development is associated with an increased risk of developing cardiovascular disease, type 2 diabetes (T2D) and adiposity later in life. However, definitions of intrauterine growth restriction (IUGR) and small for gestational age (SGA) are based on simple statistical approaches that may misclassify infants with a normal developmental profile and vice versa. We used an unbiased global profiling approach to identify gene expression patterns in umbilical cord tissue from 38 infants and identified a set of 466 genes which separated the subjects into 2 distinct groups – one biased towards lower birth weight and one biased towards normal birth weight. The data suggest that approximately 30% of children of normal size have a molecular profile more typical of impaired fetal development and who may be on a programmed trajectory. Differences in expression between the two groups encompassed 384 upregulated and 82 downregulated genes. Molecular profiling at birth may have utility in identifying markers that potentially reflect antenatal developmental and may be predictive of future phenotypic development after birth. Importantly, it may provide an alternative to the current classification of infants using birth weights. RNA from umbilical cord tissue from full term neonates was extracted and hybridized. Separation into 2 distinct groups, independent of birth weight, but based solely on gene expression levels was analysed by Genespring. After appropriate statistical analysis, one group was keenly associated with a higher birth weight (22 samples) while the other was associated with a lower birth-weight (18 samples). Technical replicates were included for all 40 samples.