Clinical and molecular evaluation of insulin autoimmune syndrome in a woman with Graves' disease who subsequently became pregnant: A case report.

Insulin autoimmune syndrome or Hirata's disease is a rare condition characterized by hypoglycemia associated with endogenous autoimmune hyperinsulinism. This report concerns the case of a 28-year-old Latin American woman with Graves' disease who developed insulin autoimmune syndrome and then subsequently became pregnant. She displayed symptoms related to severe hypoglycemia due to hyperinsulinemia, elevated C-peptide, and anti-insulin antibodies. Prior to pregnancy she was treated with corticosteroids and had ablative treatment with iodine-131. During follow-up of both conditions, the patient became pregnant, and clinically and biochemically hyperthyroid, for which total thyroidectomy was performed during the second trimester of pregnancy. Anti-insulin antibodies, blood glucose, and C-peptide remained normal throughout pregnancy. At 40 weeks of gestation she gave birth to a healthy female newborn with normal blood glucose values. Molecular genetic analysis determined the following genotypes: HLA-DRB1*03:01 / HLA-DRB1*04:01 in the mother; and HLA-DRB1*04:01 / HLA-DRB1*08:02 in the daughter. Because some HLA-DRB1*04 alleles are associated with susceptibility to insulin autoimmune syndrome induced by environmental factors, the patient was advised regarding the future use of drugs with a sulfhydryl group and possible triggering factors for insulin autoimmune syndrome. At 6-month follow-up the daughter presented normal growth and development, as well as normal plasma glucose values, and this remained the case at five-year follow-up.

A multicenter study on the prevalence and spectrum of mutations in the otoferlin gene (OTOF) in subjects with nonsyndromic hearing impairment and auditory neuropathy.

Autosomal recessive nonsyndromic hearing impairment (NSHI) is a heterogeneous condition, for which 53 genetic loci have been reported, and 29 genes have been identified to date. One of these, OTOF, encodes otoferlin, a membrane-anchored calcium-binding protein that plays a role in the exocytosis of synaptic vesicles at the auditory inner hair cell ribbon synapse. We have investigated the prevalence and spectrum of deafness-causing mutations in the OTOF gene. Cohorts of 708 Spanish, 83 Colombian, and 30 Argentinean unrelated subjects with autosomal recessive NSHI were screened for the common p.Gln829X mutation. In compound heterozygotes, the second mutant allele was identified by DNA sequencing. In total, 23 Spanish, two Colombian and two Argentinean subjects were shown to carry two mutant alleles of OTOF. Of these, one Colombian and 13 Spanish subjects presented with auditory neuropathy. In addition, a cohort of 20 unrelated subjects with a diagnosis of auditory neuropathy, from several countries, was screened for mutations in OTOF by DNA sequencing. A total of 11 of these subjects were shown to carry two mutant alleles of OTOF. In total, 18 pathogenic and four neutral novel alleles of the OTOF gene were identified. Haplotype analysis for markers close to OTOF suggests a common founder for the novel c.2905_2923delinsCTCCGAGCGCA mutation, frequently found in Argentina. Our results confirm that mutation of the OTOF gene correlates with a phenotype of prelingual, profound NSHI, and indicate that OTOF mutations are a major cause of inherited auditory neuropathy.

Program for the conservation and promotion of hearing among adolescents.

PURPOSE: We describe a program for the promotion of hearing conservation aimed at the adolescent population. The intent of our program is to (a) detect hearing disorders early, as well as to establish their relation to psychosocial and acoustic factors; (b) devise a follow-up procedure to study relevant variables; (c) evaluate the relation between hearing disorders and genetic factors, and (d) raise the social awareness of the effects of noise and its consequences. METHOD: This program, designed to be carried out over a 7-year period, focuses on participants from technical schools in the city of Cordoba, Argentina. Every student will be examined at age 14-15 years and will be reexamined at age 17-18. There will be a yearly follow-up in those cases in which disorders are detected. RESULTS AND CONCLUSIONS: We discuss the organization and planning of this program, together with its launching in the first of the selected schools. We also describe the findings on the following topics: (a) the hearing data on adolescents (age 14-15 years); (b) their recreational habits, personality traits, and attitudes; and (c) the sound immision characteristics these individuals are exposed to during recreational activities.

[Genetic study of hearing loss in families from Argentina]. / Estudio genético de hipoacusia en familias de Argentina.

Recent advances in molecular genetics as well as improved strategies for the prevention and control of non-syndromic hearing loss (NSHL) have contributed to the rising importance of their inherited causes. In this study we report 32 families from Argentine with one (sporadic) or more (familial) individuals affected. All the families were initially screened for mutations in three autosomal nuclear genes and one mutation in mitochondrial DNA. These genes have been found in a great number of familial or sporadic cases of congenital deafness in Caucasians. The mutant allele 35 del G of connexin 26 (GJB2, locus DFNB1 on 13q12) was present in three families. We have investigated the gene encoding otoferlin (OTOF, locus DFNB9 on 2p22-p23) and we found the Q829X mutation in heterocigosity in two families. We have also identified in heterocigosity the 342-kb deletion of connexin 30 (GJB6, locus DFNB1 on 13q12) in one family. On the other hand, we have not found any patient with mitochondrial mutation. Since the screening for other mutations is very expensive, our main goal is to investigate the most frequent mutations in each separate gene in the argentine population and to develop simple and specific tests for each frequent mutations.

Estudio genético de hipoacusia en familias de Argentina / Genetic study of hearing loss in families from Argentina

Los últimos avances en genética molecular como así también el desarrollo de estrategias para la prevención y control de las hipoacusias no sindrómicas (HNS), han contribuido al esclarecimiento de las causas hereditarias de las mismas. En este estudio, se seleccionaron 32 familias argentinas con uno (esporádico) o más (familiar) individuos afectados. El análisis genético consistió en la búsqueda de tres genes autosómicos nucleares y uno en el ADN mitocondrial. Estos genes se localizaron en un gran número de casos familiares o esporádicos de sorderas congénitas en Caucásicos. El alelo mutado 35 del G de la conexina 26 (GJB2, locus DFNB1 en 13g12) se presentó en tres familias. Además se investigó el gen que codifica otoferlina (OTOF locus DFNB9 en 2p22-23) encontrándose en dos familias la mutación Q829X en heterocigocidad. También se identificó en una familia portadora heterocigota la deleción de 342 Kb en la conexina 30 (GJB6, locus DFNB1 en 13g12). Por otro lado, no encontramos ningún paciente con la mutación mitocondrial. Debido a que la búsqueda de otras mutaciones es demasiado costosa, nuestro principal objetivo es investigar aquellas mas frecuentes en la población argentina, a fin de desarrollar test simples y específicos para cada una de ellas.