Molecular Genetics
Genome-wide association studies (GWAS) for Crohn’s disease (CD) have identified loci explaining ~20% of the total genetic risk of CD. Part of the other genetic risk loci is probably partly hidden among signals discarded by the multiple testing correction needed in the analysis of GWAS data. Strategies for finding these hidden loci require large replication [...]
The discovery of ‘high-risk’ de novo copy number variants (CNVs) associated with neuropsychiatric disorders such as schizophrenia offers the opportunity to translate these findings into useful tools for clinical geneticists. However, this will require estimation of penetrance for these variants, which has not yet been properly considered. To facilitate this process, we estimated the penetrance [...]
Genetic variation in both innate and adaptive immune systems is associated with Crohn’s disease (CD) susceptibility, but much of the heritability to CD remains unknown. We performed a genome-wide association study (GWAS) in 896 CD cases and 3204 healthy controls all of Caucasian origin as defined by multidimensional scaling. We found supportive evidence for 21 [...]
Gli3 is a zinc-finger transcription factor whose activity is dependent on the level of hedgehog (Hh) ligand. Hh signaling has key roles during endochondral ossification; however, its role in intramembranous ossification is still unclear. In this study, we show that Gli3 performs a dual role in regulating both osteoprogenitor proliferation and osteoblast differentiation during intramembranous [...]
Several neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), are characterized by the presence of misfolded proteins, thought to trigger neurotoxicity. Some familial forms of ALS (fALS), clinically indistinguishable from sporadic ALS (sALS), are linked to superoxide dismutase 1 (SOD1) gene mutations. It has been shown that the mutant SOD1 misfolds, forms insoluble aggregates and impairs [...]
F1Fo-ATP synthase is a key enzyme of mitochondrial energy provision producing most of cellular ATP. So far, mitochondrial diseases caused by isolated disorders of the ATP synthase have been shown to result from mutations in mtDNA genes for the subunits ATP6 and ATP8 or in nuclear genes encoding the biogenesis factors TMEM70 and ATPAF2. Here, [...]
Many neurodegenerative diseases exhibit protein accumulation and increased oxidative stress. Therapeutic strategies include clearing aggregate-prone proteins by enhancing autophagy or decreasing oxidative stress with antioxidants. Many autophagy-inducing stimuli increase reactive oxygen species (ROS), raising concerns that the benefits of autophagy up-regulation may be counterbalanced by ROS toxicity. Here we show that not all autophagy inducers [...]
Complexin 2 is a protein modulator of neurotransmitter release that is downregulated in humans suffering from depression, animal models of depression and neurological disorders such as Huntington’s disease in which depression is a major symptom. Although complexin 2 knockout (Cplx2–/–) mice are overtly normal, they show significant abnormalities in cognitive function and synaptic plasticity. Here [...]
Deficiency of the transcription factor Cited2 in mice results in cardiac malformation, adrenal agenesis, neural tube, placental defects and partially penetrant cardiopulmonary laterality defects resulting from an abnormal Nodal->Pitx2c pathway. Here we show that a maternal high-fat diet more than doubles the penetrance of laterality defects and, surprisingly, induces palatal clefting in Cited2-deficient embryos. Both [...]
Turner syndrome (TS) results from whole or partial monosomy X and is mediated by haploinsufficiency of genes that normally escape X-inactivation. Although a 45,X karyotype is observed in half of all TS cases, the most frequent variant TS karyotype includes the isodicentric X chromosome alone [46,X,idic(X)(p11)] or as a mosaic [46,X,idic(X)(p11)/45,X]. Given the mechanism of [...]
Huntington’s disease (HD) is a polyglutamine (polyQ) disease caused by an expanded CAG tract within the coding region of Huntingtin protein. Mutant Huntingtin (mHtt) is ubiquitously expressed, abundantly in neurons but also significantly in glial cells. Neuron-intrinsic mechanism and alterations in glia-to-neuron communication both contribute to the neuronal dysfunction and death in HD pathology. However, [...]
Huntington’s disease (HD) is an incurable autosomal-dominant neurodegenerative disorder initiated by an abnormally expanded polyglutamine domain in the huntingtin protein. It is proposed that abnormal mitochondrial Ca2+ capacity results in an increased susceptibility to mitochondrial permeability transition (MPT) induction that may contribute significantly to HD pathogenesis. The in vivo contribution of these hypothesized defects remains [...]
Many epidemiologic studies have associated human mitochondrial haplogroups to rare mitochondrial diseases like Leber’s hereditary optic neuropathy or to more common age-linked disorders such as Parkinson’s disease. However, cellular, biochemical and molecular-genetic evidence that is able to explain these associations is very scarce. The etiology of multifactorial diseases is very difficult to sort out because [...]
Heterozygous mutations in PAX6 are causative for aniridia, a condition that is frequently associated with juvenile glaucoma. Defects in morphogenesis of the iridocorneal angle, such as lack of trabecular meshwork differentiation, absence of Schlemm’s canal and blockage of the angle by iris tissue, have been described as likely causes for glaucoma, and comparable defects have [...]
Human amniotic fluid stem cells (hAFSCs) can be grown in large quantities, have a low risk for tumour development and harbour a high differentiation potential. They are a very promising new fetal stem cell type for cell-based therapy approaches and for studying differentiation processes without raising the ethical concerns associated with embryonic stem cells. Recently, [...]
Autosomal recessive polycystic kidney disease (ARPKD) is a significant hereditary renal disease occurring in infancy and childhood, which presents with greatly enlarged echogenic kidneys, ultimately leading to renal insufficiency and end-stage renal disease. ARPKD is caused by mutations in a single gene PKHD1, which encodes fibrocystin/polyductin (FPC), a large single transmembrane protein generally known to [...]
