CHOP Gene Experts Can Discuss New Study on Low Birth Weights, Type 2 Diabetes


A new international gene study has discovered two gene variants on chromosome 3 that predispose babies to having a lower birth weight. The genes also are linked to the development of type 2 diabetes later in life, based on research by the Early Growth Genetics Consortium on DNA from more than 10,000 individuals in three European countries. Dr. Mark McCarthy, of the Wellcome Trust Centre for Human Genetics at the University of Oxford in the U.K., led the study, published today in Nature Genetics.

The genes have a modest but measurable effect, reducing a newborn’s birthweight by an average of about four ounces. The researchers said the impact on birthweight is comparable to that of a mother smoking four to five cigarettes daily in the last three months of pregnancy. Lower birthweight is already known to increase a person’s risk of later disease — including type 2 diabetes.

Two leading genetics researchers at The Children’s Hospital of Philadelphia participated in this study by analyzing large sample sets that supported the gene finding. Hakon Hakonarson, MD, PhD, and Struan F. A. Grant, PhD, are the director and associate director, respectively, of the Center for Applied Genomics at Children’s Hospital, and can discuss the significance of the study.

Hakonarson and Grant analyzed 5,300 samples from children at CHOP in one of the replication studies that reinforced the findings of the study. The overall study also confirmed the 2009 discovery by Hakonarson and Grant that another gene, CDKAL1, is associated with both low birthweight and the risk of type 2 diabetes. Both researchers will continue to collaborate with the European consortium to discover additional genes associated with birth weight and other growth parameters in developing children.

The Center for Applied Genomics is one of the world’s largest programs for analyzing genes in pediatric diseases. Since its launch in 2006, it has discovered genes with important roles in autism, asthma, obesity, ADHD, inflammatory bowel disease, diabetes and the childhood cancer, neuroblastoma. Hakonarson led a 2009 study that located the first common gene site that predisposes people to autism spectrum disorders. Grant has a special interest in metabolic disease, and was a lead author of a 2006 study that uncovered a gene implicated in 20 percent of all cases of type 2 diabetes. Both scientists are part of an ongoing project at Children’s Hospital seeking genes associated with childhood obesity.

To arrange an interview with Dr. Hakonarson or Dr. Grant, contact Joey McCool Ryan at The Children’s Hospital of Philadelphia
at 267-426-6070. (email: