20 February 2006
Results from the most recent Clinical Molecular Genetics Society (CMGS) annual audit of activity in UK National Health Service laboratories are now available. The 2004-5 report records a very similar number of postnatal tests as last year (63,500 as opposed to 65,000 for 2003-4); this excludes the figures for aneuploidy and leukaemia testing which contributed a further 7,000 (a rise of 2000 from the previous year).
However, there has been some shift in the proportions of different tests performed; cystic fibrosis tests now outnumber those for Fragile X, respectively representing 21% and 19% of the total number of tests, as compared with 17% and 18% last year. The next most common test indications were familial cancer BRCA gene mutations (9%) and hereditary haemochromatosis HFE gene mutations (7%), followed by tests for the Factor V Leiden mutation, MMR gene mutations (for HNPCC), spinocerebellar ataxias and thalassaemia, each accounting for around 4% of the total. In all, over 300 different types of test were performed.
Prenatal testing levels rose slightly since the previous year, with a total of 1327 reports (excluding those for aneuploidy) compared with 1260 the previous year. Cystic fibrosis was once again the most common indication, accounting for 32% of all tests (2003-4 figure 34%), but the proportion of haemoglobin disorders has risen, with sickle-cell anaemia and beta-thalassaemia tests accounting for at 21% and 9% of the total, respectively, compared with 18% and 7% in 2003-4. The proportion of Duchenne muscular dystrophy tests remained level at 8%.
The audit also reports on predictive and confirmatory testing performed by the CMGS laboratories over the last year, information requested by the Department of Health to include in the Genetics and Insurance Committee (GAIC) report. A total of 2586 such reports are recorded, of which 2109 were classed as predictive, for over 50 different disorders. By far the most common predictive test was for familial breast cancer (BRCA1/2 genes), followed by Huntington