Genomic technologies have enabled the sequencing of childhood cancer patients to investigate genetic predisposition. This review compares 6 studies of selected cohorts of childhood cancer patients reporting clinically relevant pathogenic germline variants in a broad spectrum of genes associated with susceptibility to both adult and paediatric cancers. We identified differences in the reported incidence of […]
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Mosaicism and incomplete penetrance of PCDH19 mutations
Point mutations or rearrangements involving the PCDH19 gene located on Xq22.1 cause epilepsy and mental retardation mainly in females. However, affected males with mosaic PCDH19 mutations have also been reported. It is hypothesized that cellular interference mechanism is the main pathogenic mechanism. In our 42 PCDH19-related epilepsy families, five mosaic individuals, four males and one female, […]
Leveraging the Power of New Molecular Technologies in the Clinical Setting Requires Unprecedented Awareness of Limitations and Drawbacks: Experience of One Diagnostic Laboratory
Although new molecular technologies and computational prediction tools offer wide-raging opportunities in genetic diagnostic settings, they have many limitations. We contextualize these limitations by investigating incorrect variant detection in genomic regions of high sequence similarities and from inappropriate computational analysis. For instance, we observed a 5% false positive rate in MYH7 variant detection due to […]
Long-read sequencing identified intronic repeat expansions in SAMD12 from Chinese pedigrees affected with familial cortical myoclonic tremor with epilepsy
Familial cortical myoclonic tremor with epilepsy (FCMTE) is an autosomal inherited disease mainly characterized by adult-onset cortical myoclonus and infrequent epilepsy. Over the past a few decades, we have used a number of genomic technologies to examine its genetic etiology but failed to identify likely pathogenic mutations. In the current study, we used long-read sequencing […]
Non-HFE mutations in haemochromatosis in China: combination of heterozygous mutations involving HJV signal peptide variants
Hereditary hemochromatosis (HH) caused by a homozygous p.C282Y mutation in hemochromatosis (HFE) gene has been well-documented in Caucasian patients with HH. However, the morbidity of HH is less reported in Asian countries. Little is known about the general patterns of mutation of HH-related gene in Chinese patients. The present study by Lv et al. provided […]
Perturbations of BMP/TGF-β and VEGF/VEGFR signalling pathways in non-syndromic sporadic brain arteriovenous malformations (BAVM)
Brain arteriovenous malformations (BAVM) represent a congenital anomaly of the cerebral vessels with a prevalence of 10–18/100,000. BAVM is the leading etiology of intracranial hemorrhage in children. To identify gene variants potentially contributing to disease, we sequenced the DNA of 100 families with a BAVM phenotype. Pathogenic variants were then studied in vivo using a […]
Homozygous variants in KIAA1549, encoding a ciliary protein, are associated with autosomal recessive retinitis pigmentosa
Retinitis pigmentosa (RP) is a genetically inherited eye disease, and is the most frequent cause of inherited blindness worldwide. More than 80 genes have been identified in which defects can cause RP, although in approximately 20-40% of the patients still no genetic explanation can be found. In this study, we have associated genetic defects in […]
Whole-genome sequencing analysis of CNV using low-coverage and paired-end strategies is efficient and outperforms array-based CNV analysis
Stanford researchers show that whole-genome sequencing (WGS) can replace microarrays for detecting copy-number variants (CNVs) in the human genome – by sequencing the samples at low coverage using benchtop next-generation DNA sequencers. Microarrays are the current standard for CNV detection in clinical diagnostics for birth defects, brain disorders, or cancer, and also in stem cell […]
Rapid Paediatric Sequencing (RaPS): comprehensive real-life workflow for rapid diagnosis of critically ill children
To enable optimal care, critically ill children on intensive care units (ICU)s may benefit from rapid genetic diagnosis. We developed a workflow incorporating whole genome sequencing and causal variant identification in as little as 4 days. We investigated 24 individuals with suspected rare diseases on ICU at Great Ormond Street Hospital using this workflow. We […]
XRCC2 mutation causes meiotic arrest, azoospermia and infertility
In most eukaryotes, meiotic homologous recombination (HR) is mediated by two recombinase systems, namely, the ubiquitous RAD51 and meiosis-specific DMC1. In the RAD51-mediated HR system, five paralogs are essential for normal RAD51 function. Meanwhile, given the embryonic lethality of RAD51 or any RAD51 paralog knockouts, the role of RAD51 in mammalian meiosis is unclear. This […]