Thanks to researchers working on the world’s largest diagnostic sequencing program, a total of 12 new genetic causes have been discovered for rare developmental disorders. These represent the initial findings of a long-term project that aims to sequence 100,000 genomes by 2017. Share on Pinterest The Deciphering Developmental Disorders program is the largest study of its kind in the world. According to the researchers in a paper published in Nature, up to half of children with severe developmental disorders of probable genetic origin go without a genetic diagnosis for their conditions. The Deciphering Developmental Disorders (DDD) program aims to remedy this and will analyze data from 12,000 families taken from across the UK and Republic of Ireland. It is the largest nationwide and genome-wide diagnostic sequencing program in the world. “Working at enormous scale, both nationwide and genome-wide, is critical in our mission to find diagnoses for these families,” explains Dr. Helen Firth, the clinical lead for the DDD program. The initial findings come from analysis of the first 1,133 samples of data and have resulted in a 10% increase in the proportion of patients that can be diagnosed.

How the program works The DDD began in 2010 and is a collaboration between the British National Health Service (NHS) and the Wellcome Trust Sanger Institute – a charitable foundation that supports medical research. Funding for the project is provided by the Wellcome Trust and the British Department of Health. Involving 180 clinicians from 24 different regional genetics services, the DDD project has so far comprehensively analyzed every gene in 1,133 children with rare developmental disorders. All the clinical information for these participants is compiled into a database alongside the genetic variants from each patient’s genome. The database allows the researchers to compare data for patients who live hundreds of miles apart. If patients with similar symptoms are found to have similar genomic mutations, the search for causative mutations for certain disorders becomes more focused. “This project would not have been possible without the nationwide reach of the UK National Health Service, which has enabled us to unite a number of families who live hundreds of miles apart but whose children share equivalent mutations and very similar symptoms,” explains Dr. Firth. Out of the 12 newly identified genetic causes for developmental disorders, four were discovered after observing identical mutations in two or more unrelated children living at great distance from each other. Elsewhere, a new, distinct dysmorphic syndrome was found by the researchers after assessing the similarity in symptoms and facial features of two unrelated children with identical mutations of a particular gene. PCGF2, the gene in question, is involved in the regulation of genes crucial to embryo development.