Two of the genes in the deleted region were of particular interest to researchers because of their potential role in the heart and limb anomalies in the children. TBX2 and TBX4 are members of a closely related gene family, the T-box genes, that is involved in development. Mutations of TBX4 have been identified in individuals with small patella syndrome, characteristic features of which include delayed tissue formation of the pelvic bones and femur and foot anomalies. Several other genetic disorders for which heart and limb defects are characteristic features have been associated with disruption of T-box genes, which led the researchers to suggest the newly reported disorder is a similar heart-hand syndrome.

In a substantial proportion of children with mental retardation and developmental delays, the genetic basis is unknown, said Dr. Blake C. Ballif, Director of Product Development and Research at Signature Genomic Laboratories and lead author of the study. Therefore, the identification of a previously unknown genetic aberration sheds further light on the genetic basis of human disease, in addition to providing an answer for these children and their families.

Said Dr. Ballif, In addition, this report represents a collaborative academic effort by several otherwise competing diagnostic laboratories to disseminate important clinical and molecular information that significantly contributes to our understanding of the molecular basis of human genetic disease.

Source Signature Genomic Laboratories