Survival is reduced in GBA carriers compared to noncarriers; this seems to be partially independent from the increased risk for early dementia. The risk for dementia is strongly modulated by type of mutation. In the clinical continuum between PD and DLB, patients with GBA mutations seem to localize midway, with carriers of severe mutations closer to DLB than to idiopathic PD. Ann Neurol 2016;80:662-673.

Several diseases have been clinically or genetically related to cystic fibrosis (CF), but a consensus definition is lacking. Here, we present a proposal for consensus guidelines on cystic fibrosis transmembrane conductance regulator (CFTR)-related disorders (CFTR-RDs), reached after expert discussion and two dedicated workshops. A CFTR-RD may be defined as "a clinical entity associated with CFTR dysfunction that does not fulfil diagnostic criteria for CF". The utility of sweat testing, mutation analysis, nasal potential difference, and/or intestinal current measurement for the differential diagnosis of CF and CFTR-RD is discussed. Algorithms which use genetic and functional diagnostic tests to distinguish CF and CFTR-RDs are presented. According to present knowledge, congenital bilateral absence of vas deferens (CBAVD), acute recurrent or chronic pancreatitis and disseminated bronchiectasis, all with CFTR dysfunction, are CFTR-RDs.

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Progressive familial intrahepatic cholestasis type 3 (PFIC3) is an autosomal-recessive disorder due to mutations in the ATP-binding cassette, subfamily B, member 4 gene (ABCB4). ABCB4 is the liver-specific membrane transporter of phosphatidylcholine, a major and exclusive component of mammalian bile. The disease is characterized by early onset of cholestasis with high serum c-glutamyltranspeptidase activity, which progresses into cirrhosis and liver failure before adulthood. Presently, about 20 distinct ABCB4 mutations associated to PFIC3 have been described. We report the molecular characterization of 68 PFIC3 index cases enrolled in a multicenter study, which represents the largest cohort of PFIC3 patients screened for ABCB4 mutations to date. We observed 31 mutated ABCB4 alleles in 18 index cases with 29 distinct mutations, 25 of which are novel. Despite the lack of structural information on the ABCB4 protein, the elucidation of the three-dimensional structure of bacterial homolog allows the three-dimensional model of ABCB4 to be built by homology modeling and the position of the mutated amino-acids in the protein tertiary structure to be located. In a significant fraction of the cases reported in this study, the mutation should result in substantial impairment of ABCB4 floppase activity. The results of this study provide evidence of the broad allelic heterogeneity of the disease, with causative mutations spread along 14 of the 27 coding exons, but with higher prevalence on exon 17 that, as recently shown for the closely related paralogous ABCB1 gene, could contain an evolutionary marker for mammalian ABCB4 genes in the seventh transmembrane segment.

Objective: Diabetes frequently complicates cystic fibrosis (CF) without fasting hyperglycemia or despite spontaneous hypoglycemia (anecdotally ascribed to malnutrition), whose prevalence, clinical meaning, and relationship with glucose tolerance and clinical/nutritional status were not previously investigated. The relationship of CF genotype with insulin secretion control is also unclear. Design and methods: A total of 129 CF patients without stable diabetes received 188 oral glucose tolerance tests. Distribution of fasting plasma glucose (FPG), glucose, insulin and C-peptide responses, clinical/nutritional variables, and their relationships were analyzed. Results: FPG!60 mg/dl (3.3 mmo/l) was detected in 14% of studies and reactive hypoglycemia (PG!50 mg/dl (2.8 mmo/l)) in 15%. OGTT-based diabetes frequency was similar in the lowest quartile (Q1) and Q2-3 for FPG (10 and 8%), with higher glucose increment and area under the curve in Q1. Insulin and C-peptide levels were similar among FPG quartiles. Class I cystic fibrosis transmembrane conductance regulator mutation carriers had higher insulin concentrations than class II, especially in Q1 for FPG. Age, sex, nutritional, and anthropometric parameters including fat and lean body mass were unrelated to FPG. Lower FPG was associated with more frequent hospitalization rates (PZ0.002) and lower Shwachman scores (PZ0.041). Steroids weaning was accurately evaluated but then excluded as a possible cause of hypoglycemia. Conclusions/interpretation: Fasting asymptomatic hypoglycemia is frequent and possibly related to inappropriate insulin secretion control in class I mutation carriers. Low FPG does not exclude impaired glucose tolerance (IGT) and diabetes in CF and reflects worse clinical status.

Cystic fibrosis (CF) is a monogenic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, with lung and liver manifestations. Because of pitfalls of gene therapy, novel approaches for reconstitution of the airway epithelium and CFTR expression should be explored. In the present study, human amniotic mesenchymal stem cells (hAMSCs) were isolated from term placentas and characterized for expression of phenotypic and pluripotency markers, and for differentiation potential towards mesoderm (osteogenic and adipogenic) lineages. Moreover, hAMSCs were induced to differentiate into hepatocyte-like cells, as demonstrated by mixed function oxidase activity and expression of albumin, alpha1-antitrypsin, and CK19. We also investigated the CFTR expression in hAMSCs upon isolation and in coculture with CF airway epithelial cells. Freshly isolated hAMSCs displayed low levels of CFTR mRNA, which even decreased with culture passages. Following staining with the vital dye CM-DiI, hAMSCs were mixed with CFBE41o- respiratory epithelial cells and seeded onto permeable filters. Flow cytometry demonstrated that 33–50% of hAMSCs acquired a detectable CFTR expression on the apical membrane, a result confirmed by confocal microscopy. Our data show that amniotic MSCs have the potential to differentiate into epithelial cells of organs relevant in CF pathogenesis and may contribute to partial correction of the CF phenotype.

Cystic fibrosis (CF) is the most frequent lethal genetic disorder among Caucasians. It depends on alterations of a chloride channel expressed by most epithelial cells and encoded by CFTR gene. Also using scanning techniques to analyze the whole coding regions of CFTR gene, mutations are not identified in up to 10% of CF alleles, and such figure increases in CFTR-related disorders (CFTR-RD). Other gene regions may be the site of causing-disease mutations. We searched for genetic variants in the 1500 bp of CFTR 3′ untranslated region, typical target of microRNA (miRNA) posttranscriptional gene regulation, in either CF patients with the F508del homozygous genotype and different clinical expression (n = 20), CF (n = 32) and CFTR-RD (n = 43) patients with one or none mutation after CFTR scanning and in controls (n = 50). We identified three SNPs, one of which, the c.*1043A>C, was located in a region predicted to bind miR-433 and miR-509-3p. Such mutation was peculiar of a CFTR-RD patient that had Congenital Bilateral Absence of Vas Deferens (CBAVD), diffuse bronchiectasis, a borderline sweat chloride test and the heterozygous severe F508del mutation on the other allele. The expression analysis demonstrated that the c.*1043A>C increases the affinity for miR-509-3p and slightly decreases that for the miR-433. Both miRNAs cause in vitro a reduced expression of CFTR protein. Thus, the c.*1043A>C may act as a mild CFTR mutation enhancing the affinity for inhibitory miRNAs as a novel pathogenetic mechanism in CF.

in 57%, duplications in 11% and small mutations in 32%. In BMD, we found deletions in 78%, duplications in 9% and small mutations in 13%. In BMD, there are a higher number of deletions, and small mutations are more frequent than duplications. Among small mutations that are generally frequent in both phenotypes, 44% of DMD and 36% of BMD are nonsense, thus, eligible for stop codon read-through therapy; 63% of all out-of-frame deletions are eligible for single exon skipping. Patients were also assigned to Italian regions and showed interesting regional differences in mutation distribution. The full genetic characterization in this large, nationwide cohort has allowed us to draw several correlations between DMD/BMD genotype landscapes and mutation frequency, mutation types, mutation locations along the gene, exon/intron architecture, and relevant protein d o m a i n , w i t h e ff e c t s on p o p u l a t i o n ge n e t i c c h a r a c t e r i s t i c s a n d ne w personalized therapies.