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PurposeIn addition to environmental causes such as TORCH infection, trauma and drug or chemical exposure, childhood cataracts (CC) frequently have a genetic basis. They may be isolated or syndromic and have been associated with mutations in over 110 genes. We have recently demonstrated that next-generation sequencing (NGS), a high throughput sequencing technique that enables the parallel sequencing of multiple genes, is ideally suited to the investigation of bilateral CC. This study assesses the diagnostic outcomes of traditional routine investigations and compares this with outcomes of NGS testing.MethodsA retrospective review of the medical records of 27 consecutive patients with bilateral CC presenting in 2010–2012 was undertaken. The outcomes of routine investigations in these patients, including TORCH screen, urinalysis, karyotyping, and urinary and plasma organic amino acids, were collated. The success of routine genetic investigations undertaken over 10 years (2000–2010) was also assessed.ResultsBy April 2014, the underlying cause of bilateral CC had been identified in just one of 27 patients despite 44% (n=12) receiving a full ‘standard’ investigative work-up and 22% (n=6) investigations in addition to the standard work-up. Fifteen of these patients underwent NGS testing and nine (60%) of these received a diagnosis for their CC.ConclusionThe frequency of patients receiving a diagnosis for their CC after standard care and the time taken to diagnosis was disappointing. NGS testing improved diagnostic rates and time to diagnosis, as well as changing clinical management. These data serve as a baseline for future evaluation of novel diagnostic modalities.

3-M syndrome is an autosomal recessive disorder characterised by pre- and post-natal growth restriction, facial dysmorphism, normal intelligence and radiological features (slender long bones and tall vertebral bodies). It is known to be caused by mutations in the genes encoding cullin 7, obscurin-like 1 and coiled-coil domain containing 8. The mechanisms through which mutations in these genes impair growth are unclear. The aim of this study was to identify novel pathways involved in the growth impairment in 3-M syndrome. RNA was extracted from fibroblast cell lines derived from four 3-M syndrome patients and three control subjects, hybridised to Affymetrix HU 133 plus 2.0 arrays with quantitative real-time PCR used to confirm changes found on microarray. IGF-II protein levels in conditioned cell culture media were measured by ELISA. Of the top 10 downregulated probesets, three represented IGF2while H19was identified as the 23rd most upregulated probeset. QRT-PCR confirmed upregulation of H19(P<0.001) and downregulation of IGF2(P<0.001). Levels of IGF-II secreted into conditioned cell culture medium were higher for control fibroblasts than those for 3-M fibroblasts (10.2±2.9 vs 0.6±0.9 ng/ml, P<0.01). 3-M syndrome is associated with a gene expression profile of reduced IGF2expression and increased H19expression similar to that found in Silver–Russell syndrome. Loss of autocrine IGF-II in the growth plate may be associated with the short stature seen in children with 3-M syndrome.