Project description:Genes involved in distinct diabetes types suggest shared disease mechanisms. We show that rare ONECUT1 coding variants cause monogenic recessive diabetes (neonatal or very early-onset, syndromic) in two unrelated patients, and monogenic dominant diabetes (early adult-onset) in heterozygous relatives of these and 13 additional unrelated cases. Patients heterozygous for rare ONECUT1 coding variants define a subgroup of T2D with early-onset diabetes and other features. In addition, common regulatory ONECUT1 variants are associated with multifactorial T2D. Directed differentiation of human pluripotent stem cells to the pancreatic lineage revealed that loss of ONECUT1 impairs pancreatic progenitor formation and a subsequent endocrine program. We uncovered that ONECUT1 activates the pro-endocrine genes NKX6.1 and NKX2.2 through binding to their cis-regulatory elements. Globally, ONECUT1-directed gene transcription occurs in association with major islet transcription factors, at clusters of pancreas- and endocrine-specific enhancers within open chromatin. ONECUT1 regulates a transcriptional and epigenetic machinery critical for proper endocrine pancreatic development, involved in a spectrum of diabetes, monogenic recessive and dominant, and multifactorial.
Project description:Obesity is considered a multifactorial disorder with high heritability (50-75%), probably higher in early-onset and severe cases. Although rare monogenic forms and several genes and regions of susceptibility, including CNVs, have been defined, the genetic causes underlying the disease still remain largely unknown. We aimed to identify novel genetic and genomic abnormalities in a cohort of Spanish children with severe non-syndromic early-onset obesity (EOO). We obtained molecular karyotypes of 157 children with EOO. Large and rare CNVs were validated and segregated in the family. A higher burden of duplication-type CNVs was detected in EOO patients versus controls (OR=1.85, p-value=0.008).
Project description:FAMIN (LACC1, C13orf31) loss-of-function causes systemic juvenile idiopathic arthritis and very early-onset inflammatory bowel disease, while a common I254V substitution results in hypomorphic function and increases susceptibility to Crohn’s disease and leprosy. In this study, we compare the mRNA transcriptional profiles of M0, M1 and M2-polarised bone marrow-derived macrophages from mice engineered at their endogenous locus to express human non-risk (Faminp.254I), risk (Faminp.254V) and monogenic (Faminp.284R) disease variants.
Project description:Diabetes is a complex genetic disease affecting millions of people worldwide. A common monogenic form of diabetes is glucokinase (GCK) maturity-onset diabetes of the young (GCK-MODY), which is caused by heterozygous inactivating variants in the gene encoding GCK. GCK catalyzes the phosphorylation of glucose and is known as the pancreatic glucose sensor. Patients with GCK-MODY, in contrast to other diabetics, often do not require treatment but are frequently misdiagnosed and treated unnecessarily. Genetic testing can prevent this, but is hampered by the challenge of interpreting genetic variants. To address this challenge, we generated a comprehensive map of human GCK variant activity. The activity map includes 97% of the possible missense and nonsense variants and correlate with in vitro catalytic efficiency, fasting glucose levels in patients and evolutionary conservation analysis. Activity scores include both hyper- and hypoactive variants.
Project description:Background & Aims: Most inflammatory bowel diseases (IBDs) are classic polygenic disorders represented by common alleles. However, multiple determinants of very early-onset IBD characterized by a more extensive disease course remain largely unknown. The present study aimed to define the genetic architecture of pediatric and adult-onset IBDs in the Polish population. Results: Of 82 SNPs validated/replicated for association with IBD, a novel BRD2 (rs1049526) association was found in both pediatric (OR= 2.35) and adult (OR= 2.66) patients. Thirty SNPs were shared between pediatric and adult patients; 22 and 30 were unique to adult-onset and pediatric-onset IBD, respectively. WES identified numerous rare/infrequent, potentially deleterious variants in IBD-associated or innate immunity-associated genes. Both groups of variants were over-represented in affected children. Two highly deleterious homozygous variants, HLA-DRB1 c.565_566insC and NCF4 p.Arg8Trp, were found in two affected children, and WAS p.Glu131Lys was found in one child and one adult patient. Conclusions: Our GWAS revealed differences in the polygenic architecture of pediatric- and adult-onset IBD. A significant accumulation of rare/low frequency deleterious variants in affected children suggests a contribution by yet unexplained genetic components.