Auditory reception relies on the perception of mechanical stimuli by stereocilia and its conversion to electrochemical signal. Mechanosensory stereocilia are abundant in actin, which provides them with structural conformity necessary for perception of auditory stimuli. Out of three major classes of actin-bundling proteins, plastin 1 encoded by PLS1, is highly expressed in stereocilia and is necessary for their regular maintenance.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2019
We have identified a variant (c.311A>T; p.Gln104Leu) cosegregating with autosomal recessive nonsyndromic deafness in two unrelated families.
View Article and Find Full Text PDFMolecular mechanisms governing the development of the human cochlea remain largely unknown. Through genome sequencing, we identified a homozygous FOXF2 variant c.325A>T (p.
View Article and Find Full Text PDFRIPOR2 (previously known as FAM65B) localizes to stereocilia of auditory hair cells and causes deafness when its function is disturbed by mutations. Here, we demonstrate that during the morphogenesis of the hair cell bundle, absence of Ripor2 affects the orientation of this key subcellular structure. We show that Ripor2 interacts with Myh9, a protein encoded by a known deafness gene.
View Article and Find Full Text PDFWhile recent studies have revealed a substantial portion of the genes underlying human hearing loss, the extensive genetic landscape has not been completely explored. Here, we report a loss-of-function variant (c.72delA) in MPZL2 in three unrelated multiplex families from Turkey and Iran with autosomal recessive nonsyndromic hearing loss.
View Article and Find Full Text PDFThe genetics of both syndromic (SHL) and non-syndromic hearing loss (NSHL) is characterized by a high degree of genetic heterogeneity. We analyzed whole exome sequencing data of 102 unrelated probands with apparently NSHL without a causative variant in known NSHL genes. We detected five causative variants in different SHL genes (SOX10, MITF, PTPN11, CHD7, and KMT2D) in five (4.
View Article and Find Full Text PDFHair cells of the inner ear, the mechanosensory receptors, convert sound waves into neural signals that are passed to the brain via the auditory nerve. Little is known about the molecular mechanisms that govern the development of hair cell-neuronal connections. We ascertained a family with autosomal recessive deafness associated with a common cavity inner ear malformation and auditory neuropathy.
View Article and Find Full Text PDFPurpose: Autosomal recessive nonsyndromic deafness (ARNSD) is characterized by a high degree of genetic heterogeneity, with reported mutations in 58 different genes. This study was designed to detect deafness-causing variants in a multiethnic cohort with ARNSD by using whole-exome sequencing (WES).
Methods: After excluding mutations in the most common gene, GJB2, we performed WES in 160 multiplex families with ARNSD from Turkey, Iran, Mexico, Ecuador, and Puerto Rico to screen for mutations in all known ARNSD genes.
Next-generation sequencing (NGS) technologies have played a central role in the genetic revolution. These technologies, especially whole-exome sequencing, have become the primary tool of geneticists to identify the causative DNA variants in Mendelian disorders, including hereditary deafness. Current research estimates that 1% of all human genes have a function in hearing.
View Article and Find Full Text PDFHearing loss (HL) is a major public health issue. It is clinically and genetically heterogeneous.The identification of the causal mutation is important for early diagnosis, clinical follow-up, and genetic counseling.
View Article and Find Full Text PDFMutations in ANKRD11 have recently been reported to cause KBG syndrome, an autosomal dominant condition characterized by intellectual disability (ID), behavioral problems, and macrodontia. To understand the pathogenic mechanism that relates ANKRD11 mutations with the phenotype of KBG syndrome, we studied the cellular characteristics of wild-type ANKRD11 and the effects of mutations in humans and mice. We show that the abundance of wild-type ANKRD11 is tightly regulated during the cell cycle, and that the ANKRD11 C-terminus is required for the degradation of the protein.
View Article and Find Full Text PDFGenetic variants account for more than half of the cases with congenital or prelingual onset hearing loss. Autosomal recessive nonsyndromic hearing loss (ARNSHL) is the most common subgroup. Whole-exome sequencing (WES) has been shown to be effective detecting deafness-causing single-nucleotide variants (SNVs) and insertion/deletions (INDELs).
View Article and Find Full Text PDFIn a large consanguineous Turkish kindred with recessive nonsyndromic, prelingual, profound hearing loss, we identified in the gene FAM65B (MIM611410) a splice site mutation (c.102-1G>A) that perfectly cosegregates with the phenotype in the family. The mutation leads to exon skipping and deletion of 52-amino acid residues of a PX membrane localization domain.
View Article and Find Full Text PDFMegacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is characterized by prenatal-onset distended urinary bladder with functional intestinal obstruction, requiring extensive surgical intervention for survival. While it is believed to be an autosomal recessive disorder, most cases are sporadic. Through whole-exome sequencing in a child with MMIHS, we identified a de novo mutation, p.
View Article and Find Full Text PDFObjective: Hypocomplementemic urticarial vasculitis syndrome (HUVS) is characterized by recurrent urticaria along with dermal vasculitis, arthritis, and glomerulonephritis. Systemic lupus erythematosus (SLE) develops in >50% of patients with HUVS, although the pathogenesis is unknown. The aim of this study was to identify the causative DNA mutations in 2 families with autosomal-recessive HUVS, in order to reveal the pathogenesis and facilitate the laboratory diagnosis.
View Article and Find Full Text PDFMyopia is by far the most common human eye disorder that is known to have a clear, albeit poorly defined, heritable component. In this study, we describe an autosomal-recessive syndrome characterized by high myopia and sensorineural deafness. Our molecular investigation in 3 families led to the identification of 3 homozygous nonsense mutations (p.
View Article and Find Full Text PDFIdentification of the pathogenic mutations underlying autosomal recessive nonsyndromic hearing loss (ARNSHL) is difficult, since causative mutations in 39 different genes have so far been reported. After excluding mutations in the most common ARNSHL gene, GJB2, via Sanger sequencing, we performed whole-exome sequencing (WES) in 30 individuals from 20 unrelated multiplex consanguineous families with ARNSHL. Agilent SureSelect Human All Exon 50 Mb kits and an Illumina Hiseq2000 instrument were used.
View Article and Find Full Text PDFHereditary hearing loss is characterized by a high degree of genetic heterogeneity. Here we present OTOGL mutations, a homozygous one base pair deletion (c.1430 delT) causing a frameshift (p.
View Article and Find Full Text PDFType 1 diabetes (T1D) results from the interaction of genetic and environmental factors. Previous studies indicate an association between detection of Enterovirus (EV) genome in blood and the clinical onset of T1D. Insulin resistance can also represent a risk factor for progression to clinically overt T1D.
View Article and Find Full Text PDFAim: To determine the frequency of metabolic syndrome (MS) and insulin resistance (IR) in first-degree relatives of type 1 diabetic patients (FDR1) and to study the relationship between these two disorders and some clinical, biochemical and immunological characteristics.
Subjects And Methods: We studied 289 persons, of which 193 were children/adolescents and 96 were adults. Weight, height, waist and hip circumference, blood pressure, blood glucose, insulin, cholesterol, triglycerides, high-density lipoprotein-cholesterol, glutamic acid decarboxylase autoantibodies (GADA) and tyrosine phosphatase autoantibodies were determined.
Background: Incidence of type 1 diabetes varies widely around the world, probably due to ethnic differences across populations among other factors.
Aims: To determine whether there is an association between disease and ancestry proportions; and to control disease-HLA associations for possible confounding by admixture or population stratification.
Subjects And Methods: 100 cases and 129 controls participated in the study.
Background: The Cuban population is essentially a result of the admixture between Spanish, West African and, to a lesser degree, Amerindian tribes that inhabited the island.
Aim: The study analysed the genetic structure of the three principal ethnic groups from Havana City, and the contribution of parental populations to its genetic pool.
Subjects And Methods: According to genealogical information and anthropological traits, 206 subjects were classified as Mulatto, of Spanish decent or of African descent.