Genetic analysis and prenatal diagnosis of a Chinese pedigree affected with Usher syndrome due to novel compound heterozygous variants of PCDH15 gene / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical features and genetic variant in a patient with Usher syndrome.@*METHODS@#Whole exome sequencing was carried out for the patient. Suspected variants were validated by Sanger sequencing of her parents and fetus.@*RESULTS@#The proband was found to harbor compound heterozygous variants c.17_18insA (p.Tyr6Ter*) and c.4095_4096insA (p.Arg1366Lys fs*38) of the PCDH15 gene (NM_033056), which were respectively inherited from her father and mother. The same variants were not detected in 100 healthy controls. Based on the guidelines of the American Society of Medical Genetics and Genomics, both variants were predicted to be pathogenic (PVS1+PM2+PP4). By prenatal diagnosis, her fetus was found to carry the c.4095_4096insA variant. After birth, the child has passed neonatal hearing screening test, and no abnormal auditory and visual function was found after the first year.@*CONCLUSION@#The compound heterozygous variants c.17_18insA (p.Tyr6Ter*) and c.4095_4096insA (p.Arg1366Lys fs*38) of the PCDH15 gene probably underlay the Usher syndrome is this proband.

Variation analysis of genes associated with Usher syndrome type 1 in 136 Chinese deafness families / 中华耳鼻咽喉头颈外科杂志

Objective: To investigate the variation of genes associated with Usher syndrome type 1(USH1)in 136 Chinese deafness families from Henan province. Methods: The data of 136 deafness families tested by next-generation sequencing(NGS) which identified in the center of genetics and prenatal diagnosis of the First Affiliated Hospital of Zhengzhou University from November 2016 to December 2019 were analysized and the variation frequency of six genes related to Usher syndrome type 1(MYO7A, USH1C, CDH23, PCDH15, USH1G, CIB2) were summarized. Results: Five deafness families were detected nine pathogenic or likely pathogenic variations in two genes, accounting for 3.7% of all families. Among them, four families were caused by MYO7A variations and one family was caused by CDH23 variation. Meanwhile, seven variations of two genes were reported for the first time. They were c.313delG, c.5257dupA, c.5435A>T, c.5636G>C, c.5722T>G of MYO7A, and c.155_166del, c.4802delA of CDH23. The patients' vision of family 2 and family 3 had no obvious abnormality at present, but according to genetic diagnosis and walking dealy, they were considered to be USH1. Conclusions: MYO7A is the most common caustive gene associated with USH1 in Henan deafness patients, the application of next-generation sequencing technology can make USH1 patients diagnosed earlier before the visual symptoms appear.

Analysis of pathogenic variants of USH2A gene in a child with Usher syndrome type II / 中华医学遗传学杂志

OBJECTIVE@#To detect pathogenic variant in a child featuring Usher syndrome type II.@*METHODS@#Peripheral blood samples of the child and his parents were collected for the analysis of variants of hearing impairment-related genes. The findings were verified in 100 individuals with normal hearing.@*RESULTS@#The child was found to harbor compound heterozygous variants of the USH2A gene, namely c.8224-1G>C in intron 41 and c.5678C>G(p.Ser1893X) in exon 28, which were inherited respectively from his mother and father. Based on the American College of Medical Genetics and Genomics standards and guidelines, both c.8224-1G>C and c.5678C>G(p.Ser1893X) variants of USH2A gene were predicted to be pathogenic(PVS1+PM2+PM3).@*CONCLUSION@#The compound heterozygous variants c.8224-1G>C and c.5678C>G of the USH2A gene probably underlay the disease in this child. Above finding has enriched the spectrum of USH2A gene variants.

Genetic diagnosis of a pedigree affected with Usher syndrome type 1D/F / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a pedigree affected with congenital sensorineural deafness.@*METHODS@#High-throughput sequencing was carried out to analyze the coding regions of 415 genes associated with hereditary deafness in the proband. Suspected variants were verified by PCR amplification and Sanger sequencing of her parents and sister.@*RESULTS@#The proband was found to have carried a heterozygous c.5131G>A (p.Val1711Ile) variant of the CDH23 gene and a heterozygous c.2884C>T(p.Arg962Cys) variant of the PCDH15 gene, which were respectively inherited from her mother and father. Her sister (with normal hearing) was also heterozygous for the c.5131G>A (p.Val1711Ile) variant of the CDH23 gene but not the c.2884C>T (p.Arg962Cys) variant of the PCDH15 gene. Based on the guidelines of the American College of Medical Genetics and Genomics, both variants were predicted to be likely pathogenic (PS1+PM2+PP3+PP4).@*CONCLUSION@#The c.5131G>A (p.Val1711Ile) variant of the CDH23 gene and c.2884C>T (p.Arg962Cys) variant of the PCDH15 gene probably underlay the pathogenesis of Usher syndrome type 1D/F in this pedigree.

Caracterización clínica del síndrome de Usher. Provincia Holguín / Usher syndrome clinical characterization. Holguin province

Fundamento: El síndrome de Usher es una enfermedad determinada genéticamente, con una gran heterogeneidad clínica y genética; está caracterizada por hipoacusia neurosensorial de moderada a severa, retinosis pigmentaria progresiva y puede acompañarse de alteración vestibular. Por la alta prevalencia de esta enfermedad en la provincia de Holguín, se considera necesario este estudio. Objetivo: Caracterizar clínicamente todos los enfermos con diagnóstico clínico de síndrome de Usher en la provincia Holguín, en el período de enero del 2009 a enero del 2016. Metodología: Se realizó un estudio descriptivo, retrospectivo, tipo serie de casos, a los 53 pacientes con diagnóstico clínico de síndrome de Usher en la provincia Holguín. La muestra estuvo formada por los 53 enfermos residentes en la provincia. Se revisaron los registros del Centro Provincial de Retinosis Pigmentaria y las historias clínicas de estos pacientes; se recogieron los datos de interés en un instrumento que se confeccionó para ello. Las variables estudiadas fueron el sexo, la edad, edad del diagnóstico de la hipoacusia y severidad, edad del diagnóstico de la retinosis pigmentaria y los resultados de las pruebas audiológicas, lo que permitió conocer la función vestibular. Resultados: Se caracterizó clínicamente el 100 % de los enfermos estudiados. Predominó el sexo masculino (60,37 %). El 80 % presentó la retinosis pigmentaria en la primera infancia y la hipoacusia congénita profunda en 67,92 %. Las pruebas vestibulares demostraron que el 71,70 % presenta síndrome de Usher tipo II y el 28,30 % tiene el tipo I. Conclusiones: Predominó el sexo masculino, la hipoacusia precedió a la alteración visual. Se logró caracterizar clínicamente a estos afectados. Prevaleció el síndrome de Usher tipo II.

Background: Usher syndrome is a genetically determined disease with great clinical and genetic heterogeneity. This disease is characterized by sensorineural hearing loss of moderate to severe, progressive pigmentosa retinitis and may be accompanied by vestibular alteration. At the high prevalence of this disease in the province of Holguin, this study is considered necessary. Objective: To characterize all patients clinically with clinical diagnosis of Usher syndrome in Holguin province, in the period from January 2009 to January 2016. Methodology: A series types of retrospective cases, descriptive study with 53 patients with clinical diagnosis of Usher syndrome in Holguin province was conducted. The sample consisted of 53 patients residing in the province. Provincial records Pigmentosa Retinitis Pigmentosa Center and the medical records of these patients were reviewed, the data of interest are collected in an instrument that was drawn up for these. The variables studied were sex, age, age at diagnosis of hearing loss and severity, age of diagnosis of pigmentosa retinitis and the results of the audiological tests, allowing knowing the vestibular function. Results: It was possible to clinically characterize 100 % of the patients studied, predominantly male in a 60.37 %. 80 % had pigmentosa retinitis in early childhood and profound congenital hearing loss in 67.92 %. Vestibular tests showed that 71. 70 % have Usher syndrome type II and 28.30 % have the type I. Conclusions: mainly males, hearing loss preceded visual impairment. It was possible to clinically characterize those affected. It prevailed Usher syndrome type II.

Aspectos médicos, genéticos y psicosociales del síndrome Usher / Medical, genetic, and psychosocial aspects of Usher´s syndrome

El síndrome Usher es una enfermedad genética, que se caracteriza por hipoacusia neurosensorial progresiva bilateral congénita, pérdida de visión debida a la retinosis pigmentaria y en ocasiones presenta también trastornos vestibulares. Objetivo: describir los principales aspectos médicos, genéticos y psicosociales presentes en los pacientes con síndrome Usher. Método: se realizó un estudio descriptivo transversal en 14 pacientes con diagnóstico de síndrome Usher atendidos en el Centro de Retinosis Pigmentaria de Camagüey, desde 1991 hasta 2008. Resultados: los 14 pacientes provenían de familias diferentes y seis de ellos tenían antecedentes patológicos familiares. Se encontró consanguinidad entre los padres de las personas afectadas en el 35,72 % de las familias, el principal grado de parentesco fue el de primos hermanos. El síndrome Usher tipo II fue la forma más frecuente. La mayoría de los pacientes eran procedentes de zonas urbanas; los que portaban el síndrome levemente aspiraban a alcanzar un mayor nivel de escolaridad, así como aquellos procedentes de las áreas urbanas. Tenían ocupación laboral nueve; algunos con trabajos riesgosos. De los nueve, cuatro no trabajaban y sólo dos eran del sexo femenino. Conclusiones: las manifestaciones clínicas del síndrome Usher provocan una doble limitación (visual y auditiva), que son responsables de los trastornos psicológicos y sociales que se asocian al mismo. Las personas afectadas necesitan de una atención especial que contribuya a mejorar la calidad de sus vidas.

Usher´s syndrome is a genetic disease that is characterized by congenital bilateral progressive neurosensory hypoacusis, loss of vision due to retinitis pigmentosa and occasionally also presents vestibular disorders. Objective: to describe the main medical, genetic, and psychosocial aspects present in patients with Usher´s syndrome. Method: a cross-sectional descriptive study was conducted in 14 patients with Usher´s syndrome diagnosis treated at the pigmentary retinosis Center in Camagüey, from 1991 to 2008. Results: fourteen patients came from different families and six of them had family pathological history. Found consanguinity among parents of persons affected by 35,72 % of families, cousins was the main degree of kinship. Usher´s syndrome type II was the most common form. The majority of patients were from urban areas; which carried the syndrome slightly aspired to achieve a higher level of schooling, as well as those from urban areas. Nine of them had jobs, some risky works. Four out of nine, did not work and only two were female. Conclusions: clinical manifestations of Usher´s syndrome cause a double constraint (visual and auditory), which are responsible for the psychological and social disorders that are associated to it. Affected persons need a special care to help improve the quality of their lives.

Síndrome de Usher de tipo II: caracterización oftalmológica, auditiva y genética de una familia consanguínea / Type II Usher syndrome: ophthalmological, auditory, and genetic characterization of a consanguineous family

Se caracterizó a una familia consanguínea de 25 miembros, 3 de los cuales padecían el síndrome de Usher de tipo II, a través del estudio auditivo, oftalmológico y genético en el Centro de Retinosis Pigmentaria de Santiago de Cuba. Los pacientes (2 varones y 1 fémina) tenían en común: aparición de la enfermedad en la etapa juvenil, mala visión nocturna, campos visuales reducidos, hipoacusia neurosensorial y resultados normales en las pruebas vestibulares; asimismo, en genética molecular, la electroforesis en gel de poliacrilamida reveló la presencia del marcador D1S237, estrechamente ligado al gen USH2 en el cromosoma 1. Esa caracterización permitirá aplicar la terapia génica y los implantes, tanto de células madre como cocleares, según corresponda.

A consanguineous family of 25 members, 3 of whom suffered from type II Usher syndrome was characterized through the auditory, ophthalmologic, and genetic study in the Retinitis Pigmentosa Center from Santiago de Cuba. The patients (2 males and a female) had in common: occurrence of the illness during youth, bad night vision, reduced visual fields, neurosensorial hypoakusia, and normal results in the vestibular tests; also, in molecular genetics, electrophoresis in polyacrilamide gel revealed the presence of the D1S237 marker, closely linked to the gene USH2 in chromosome 1. That characterization will allow to apply the genic therapy and both implants, mother cells and cochlear, as it corresponds.

Frecuencia de mutaciones en el gen de la usherina (USH2A) en 26 individuos colombianos con síndrome de Usher, tipo II / Mutational frequencies in usherin (USH2A gene) in 26 Colombian individuals with Usher syndrome type II

Introducción. El síndrome de Usher se caracteriza por hipoacusia neurosensorial congénita, retinitis pigmentaria y disfunción vestibular. Es la causa más frecuente de sordo-ceguera en el mundo. Se divide en tres tipos clínicos y doce subtipos genéticos. El tipo II es la forma más común y cerca de 80 % de los casos corresponden al subtipo 2 del síndrome de Usher. Objetivo. Establecer la frecuencia de mutaciones en la isoforma corta del gen USH2A en individuos colombianos con síndrome de Usher, tipo II. Materiales y métodos. Se estudiaron 26 individuos colombianos con diagnóstico clínico de síndrome de Usher, tipo II. Se hizo análisis de SSCP para los 20 exones que codifican para la isoforma corta y se secuenciaron los patrones anormales. Además, se secuenció el exón 13 en todos los individuos, ya que allí se encuentra la mutación más frecuente de este gen. Resultados. La mutación más frecuente es la c.2299delG, correspondiente al 27 % de la población. La segunda mutación identificada es la p.R334W, con una frecuencia de 15 %. Se identificó un nuevo cambio, el g.129G>T,en la región 5’UTR del gen, correspondiente al 4 % de la población. Se identificaron cuatro cambios polimórficos, uno de ellos es una deleción nueva identificada en el exón 20. Conclusiones. Se logró establecer que, al menos, 38 % de la población analizada con síndrome de Usher, tipo II, presenta alguna mutación en la isoforma corta del gen de la usherina. El diagnóstico molecular se logró establecer en el 23 %.

Introduction. Usher syndrome is a disorder characterized by progressive retinitis pigmentosa, prelingual sensory hearing loss and vestibular dysfunction. It is the most frequent cause of deaf-blindness in humans. Three clinical types and twelve genetic subtypes have been characterized. Type II is the most common, and among these cases, nearly 80% have mutations in the USH2A gene. Objective. The aim of the study was to establish the mutational frequencies for the short isoform of USH2A gene in Usher syndrome type II. Materials and methods. Twenty-six Colombian individuals with Usher syndrome type II were included. SSCP analysis for 20 exons of the short isoform was performed and abnormal patterns were sequenced. Sequencing of exon 13 of the USH2A gene was performed for all the individuals because the most frequent mutation is located in this exon. Results. The most frequent mutation was c.2299delG, identified in the 27% (n=8) of the sample. The second mutation, p.R334W, showed a frequency of 15%. A new variant identified in the 5’UTR region, g.129G>T, was present in 1 individual (4%). Four polymorphisms were identified; one of them is a new deletion in exon 20, first reported in this study. Conclusions. Mutations in the usherin short isoform were identified in 38% of a sample of 26 USH2 cases. Molecular diagnosis was established in 7 of the 26.