18 February 2009
The UK Clinical Molecular Genetics Society (CMGS) has recently completed the latest annual audit of National Health Service genetics laboratories. The 2007-8 figures show a significant rise in the total number of samples processed for NHS services (as opposed to research), increasing by 40% to a total of 152,593 for the 26 out of a total of 28 laboratories that provided audit data.
For postnatal reports there was a 20% increase on the previous year to more than 99,000 in total (excluding leukaemia and DNA storage samples), and a 15% increase in single gene disorder reports. The most frequently performed tests were for cystic fibrosis (12%), Fragile X syndrome (11.6%) and familial cancer BRCA gene mutations (10%). This order is the same as for 2005-6 (see previous news), but the proportion of cystic fibrosis and Fragile X tests has fallen and that of BRCA tests increased since then. The fourth most common category of postnatal reports was for DNA bank samples (6.2%), ahead of hereditary haemochromatosis HFE gene mutations (5.7%). Factor V Leiden mutation testing has fallen from 3.6% of all postnatal reports in 2005-6, to 1.1% for 2007-8. In all, more than 400 different categories of postnatal report were recorded.
The total number of prenatal reports was similar to the previous year at more than 7500; the majority of these were for common aneuploidies (79%). The total for indications other than aneuploidy testing was 11% higher than the previous year at 1347; of these, the most common category was cystic fibrosis tests (27%), followed by cell-free fetal DNA samples for analysis (11%) – see previous news for more information about this emerging form of early non-invasive prenatal diagnosis, which may account for much of the total rise in test numbers. Sickle-cell anaemia was the third most common test indication (10%).
Numbers of predictive and confirmatory tests are now being assessed for the Genetics and Insurance Committee (GIAC) report, with a similar total number of tests recorded as for the previous year (5874). The most common test was for BRCA 1/2 mutations associated with familial breast and ovarian cancer (more than 2000 in total), followed by the most common forms of familial colorectal cancer, HNPCC (~750) and FAP (~250). Huntington’s disease, Marfan syndrome, long QT syndrome and familial hypercholersterolaemia each accounted for around 250 tests.