Learning disability is a significant impairment of the cognitive and adaptive function with onset before the age of 18 years. Around 1.2 to 1.5 million people in England and Wales have a learning disability according to the British Institute of Learning Disabilities and Mencap. This estimate is in agreement with figures of 1-3% of the population worldwide. Genetic factors are known to be a significant etiological factor. Technological advances including the use of genome-wide high-resolution microarray comparative genomic hybridisation (array CGH) have led to improved diagnostic capability. Despite compelling evidence of the diagnostic benefits of using array CGH to diagnose learning disability the introduction of array CGH into routine first-line testing of learning disability has been hindered by the perceived high cost and complexity of the test and a lack of consensus on NHS service configuration across laboratories. This is despite the UKGTN approving the first-line use of array CGH for diagnosing learning disability, developmental delay and congenital anomalies for NHS use in 20102.
This briefing presents the results of an economic evaluation comparing the costs and benefits, as applicable to a NHS clinical genetics service, of using array CGH in a first-line setting with using it as a second-line test following a negative karyotype as the most appropriate comparator.
A paper from this work on the cost effectiveness of using array CGH for diagnosing learning disability has been published and is available at PubMed