Jervell and Lange-Nielsen Syndrome in deaf school children population

To identify the patients of Jervell and Lange-Nielsen syndrome [JLNS] amongst congenitally deaf children. This was a cross-sectional study, conducted at Hamza Foundation Academy for the Deaf, and Combined Military Hospital Lahore over a period of 4 months from February to May 2012. A total of 379 children with congenital sensorineural hearing loss were included in this study. Echocardiographs of all children [ages 4-18 years] were obtained. The corrected QT [QTc] intervals of all 379 ECGs were calculated using the Bazett's formula. Using the Schwartz's criteria, patients with long QTc intervals were further evaluated for Jervell and Lange-Nielsen Syndrome. Out of 379 children, 84 [22.1%] were found to have QTc intervals equal to or longer than 0.44 seconds. As per Schwartz's criteria, 31 [36.9%] out of 84 children with Long QTc [8.17% in sample population], scored high points [4.0 to 6.0], proving presence of JLNS. A sizable proportion of congenitally deaf children had Jervell and Lange-Nielsen Syndrome in our study

[Long QT in children with congenital deafness: a brief report]

Long QT syndromes [LQT] are genetic abnormalities of ventricular repolarization, with an estimated incidence of about one per 10000 births. It is characterized by prolongation of the QT interval in electrocardiogram [EKG] and associated with a high risk for syncope and sudden death in patients. Type of this syndrome is association with congenital deafness. Our objective was to evaluate QT interval in children with congenital deafness. For 219 patients referred to Imam Khomeini Hospital audiometric clinic in 2011, questionnaire were completed. A total of 23 congenitally deaf children were included. All patients' examinations were done by a pediatric cardiologist. Electrocardiogram is conducted in all children [23 patients] with sever and deep congenital deafness. Then the QT interval was measured based on Bazett's formula. Echocardiography was also performed in these children to assess left ventricular function and the presence of mitral valve prolapse. The overall patients were two hundred and nineteen children. A total of twenty three congenitally deaf children were included and electrocardiogram was obtained. Three children had obviously prolonged QTc [0.48 +/- 0.02] second. The median age of them was 6.1 +/- 5 year, the median weight was 18 +/- 11.3 kilogram and the median of QT interval was 0.48 +/- 0.02 second. The QT interval obtained 0.48 +/- 0.02 second. In the present study we found prolonged QT in congenital deafness, thus we recommend to evaluate the electrocardiogram of children with congenital deafness.

Frecuencia de la mutación p. Q829X del gen Otoferlina (otof) en población colombiana con sordera no sindrómica / Frequency of p. Q829X Mutation in Otoferlin Gene in Colombian Population with non Syndromic Deafness

Introducción: Las pérdidas auditivas son heredables en un 50-60% de los casos. Dentro de estas, las sorderas no sindrómicas predominan y se han descrito más de 40 genes asociados. Uno de los más frecuentemente implicados es el gen de Otoferlina(OTO F). Objetivo: Determinar la frecuencia de la mutación p.Q829X en el gen OTO F en 649 individuos colombianos con sordera no sindrómica. Materiales y métodos: Se seleccionó una población de 649 individuos para realizar la búsqueda de la mutación p.Q829X por medio de la técnica PCR-RFLP. Resultados: Se identificaron 12 individuos con la mutación p.Q829X (12/649), quecorresponden a una frecuencia del 1,8%. Conclusiones: La mutación p.Q829X es la más frecuente en el gen OTO F, y la tercera luego de las mutaciones S199F y 35delG en el gen GJB2, causantes de sordera en la población analizada. Se observó variabilidad en el grado de pérdida auditiva en los individuos homocigotos para la mutación y presencia deneuropatía auditiva en el 62,5% de estos casos...

Introduction: Hearing loss is 50-60 % heritable. Among this, non-syndromic hearing loss is predominant and more than 40 genes have been reported. One of the most frequently involved is OTO F gene. Objective: To identify the frequency of mutation p.Q829X in OTO F gene, in 649 Colombian individuals with non-syndromic deafness. Materials and Methods: A total of 649 individuals were selected and screened for p.Q829X mutation using PCR-RFLP analysis. Results: p.Q829X mutation was identified in 12 deaf individuals (12/649) corresponding to a frequencyof 1,8%. Conclusions: p.Q829X mutation is the most common in OTO F gene, and the third cause after S199F and 35delG mutations in GJB2 gene, ofdeafness in the analyzed population. Variability is observed in the degree of hearing loss in individuals homozygous for the mutation and auditoryneuropathy is present in 62,5% of these cases...

Tamizaje universal de hipoacusia en el recién nacido / Universal screening of newborn hypoacusis

Neonatal hearing loss affects 1-3 from every 1000 live newborns. For optimal language and social development, proper diagnosis and treatment must be established before the first 6months of age. In Chile, screening for hearing loss is only performed on high-risk newborns weighting less than 1500 grams. However, about half of the newborns with hearing loss have no risk factors. Given the importance of this disability and the fact that it can be effectively diagnosed, a universal detection program for hearing loss becomes necessary. Further more, effective treatments for hearing loss, like hearing aids and cochlear implants are available in several institutions of our country, including the Clinical Hospital of the University of Chile. Worldwide, the most used screening methods are otoacoustic emissions and auditory brainstem evoked responses, the former, a test that detects the acoustic energy generated by the outer hair cells of the cochlea in response to a brief sound, and the latter a test that measures neural responses of the central auditory pathway. Both are objective and non-invasive techniques. Here we review evidences that support the need of creating a universal newborn hearing screening program in Chile.

Long QT syndrome in children with congenital deafness.

The Jervell and Lange-Nielson syndrome(JLN) is an infrequent form of long QT syndrome (LQTS) in which prolonged QT interval and congenital deafness exist together. We attempted to identify patients with LQTS among 127 children (age 1.2-10 years) with congenital hearing loss. The corrected QT interval was measured from 12 lead electrocardiogram(ECG) , using Bazette’s and Friedricia formulae.The QT interval was considered prolonged when it exceeded the upper limit of 440ms and 450ms, respectively. Ten children with congenital deafness had a corrected QT interval longer than 440ms. Although these children did not meet the definite criteria according to Schwartz parameters, all the 10 children could be defined as having intermediate probability of LQTS according to revised criteria. We advise that children with congenital deafness be screened for long QT syndrome .

Detecção precoce e intervenção em crianças surdas congênitas inseridas em escolas especiais da cidade de Salvador / BA / Early detection and intervention in congenital deaf children inserted in special schools of the city of Salvador / BA

Introdução: A privação auditiva interfere no desenvolvimento linguístico da criança, prejudicando sua inserção na sociedade e produzindo consequências cognitivas e emocionais, caso ela não seja inserida em um programa educacional e terapêutico precoce e adequado. Objetivo: Caracterizar o processo de detecção precoce e intervenção de crianças com perda auditiva inseridas em escolas especiais da cidade de Salvador-BA. Métodos: Foram avaliados os prontuários e realizada entrevista com as mães de 22 crianças surdas congênitas, com idade entre seis e oito anos. Resultados: A média de idade quando houve a suspeita da surdez foi de 1.2 anos e quando foram inseridas em um programa de atendimento educacional e/ou terapêutico foi de 3.5 anos. 46% das crianças usam aparelho de amplificação sonora e tiveram um acesso à prótese auditiva com 3.6 anos, em média. Apenas 37.5% fazem terapia fonoaudiológica e 9.1% é oralizada. Conclusão: As crianças surdas avaliadas tiveram acesso à linguagem de maneira tardia, sendo que algumas não utilizam um sistema de amplificação sonora ou passaram a utilizar em idades mais avançadas e poucas fazem terapia fonoaudiológica. Dessa maneira, é necessário atuar na implementação das políticas públicas direcionadas à saúde auditiva na população pediátrica e neonatal, possibilitando a atenção integral, universal e de qualidade.

Introduction: The hearing loss interferes with the child's linguistic development, impairs its insertion in the society and produces cognitive and emotional consequences in case he or she is not inserted in an early and suitable educational and therapeutic program. Objective: To characterized the early detection process and intervention in children with hearing loss inserted in special schools of the city of Salvador - BA. Method: We evaluated the records and carried out interview with mothers of 22 congenital deaf children aged from six to eight years. Results: The mean age in case of deaf suspicion was of 1.2 years and when inserted to an educational and/or therapeutic treatment program it achieved 3.5 years. 46% of the children use hearing aid and had access to the device aged 3.6 year on average. Only 36.5% undergo phonoaudiologic therapy and 9.1% maintain oral function. Conclusion: The deaf children evaluated had a late access to language and some don't use a hearing aid system or began to use it at more advanced ages and only a few follow phonoaudiological therapy. Therefore, it's necessary to promote the implementation of the public policies intended for the hearing health in the pediatric and neonatal population which enable the integral, universal and quality attention.

Sensorineural hearing impairment is a common feature of consanguineous marriage

Sensorineural hearing loss [SNHL] accounts for about 60% of all hearing loss. This is sometimes also called [Nerve deafness]. The term [Sensorineural] is used to indicate that there is either a cochlear or an eight nerve lesion. The diagnosis of Sensorineural hearing loss is made through audiometry, which shows a significant hearing loss without [The air-bone gap] that is characteristic of conductive hearing disturbances. Among various risk factors described for deafness, consanguinity is an established high risk. This work was carried out to study the prevalence of sensorineural hearing loss in offsprings of consanguineous marriage, who attended the Medical Genetics Center, Ain Shams University. The study was performed on 950 children with congenital hearing loss. Consanguineous marriage was present in 71.2% of studied cases, 47.3% of these cases, parents were 1st cousin, in 36.7% parents were 2nd cousin, 16% had remote consanguinity. 28.8% of cases were the offspring of non-consanguinous marriage. Also, the results showed that 44.2% of cases had severe degree of Sensorineural hearing loss [71-90 dBHL], 24.3% had profound hearing loss [>90 dBHL]. Autosomal dominant inheritance [AD] hearing loss was detected in 40% of cases. Autosomal recessive inheritance hearing loss was discovered in 27% of cases, and in 18.7% of study cases the hearing loss was associated with genetic syndromes, where 88.8% of these cases were associated with Down syndrome. The incidence of hereditary hearing impairement is commoner in developing counteries compared to developed counteries, so, prevention is essential to reduce the incidence of genetic hearing loss. Premarital and antenatal screening should be applied whenever possible, at least for those at risk of developing genetic diseases including hearing impairement

[Screening of DFNB4 locus in Iranian families with hereditary hearing impairment]

Mutations in the SLC26A4 gene in the DFNB4 locus is responsible for syndromic [Pendred syndrome] and non-syndromic hereditary hearing loss [HHL]. In many populations, mutations in this gene have been reported as a second cause of HHL. The objective of this study was to investigate the prevalence of SLC26A4 mutations in our HHL consanguineous families. After completing clinical evaluation and obtaining signed consent forms from each family, we included 80 families with two or more affected individuals, referred to the Genetics Research Center [GRC]. All families that previously tested negative for the DFNB1 locus were candidates for homozygosity mapping using STRs for DFNB4 locus. Families localized to this region were subjected to complete DMA sequencing. Twelve out of 80 families were mapped to DFNB4. Sequence analysis of 12 linked families revealed 10 mutations in 8 families. [T420I, 1197delT, G334V, R409H, T721M, R79X, S448L, L597S, 965insA, and L445W]. The T420I, G334V, L597S and R79X were novel mutations; we did not find any mutation in the four linked families, nor did we detect any nonsyndromic families with mutation in the SLC26A4 gene. We have been able to identify mutation in the SLC26A4 gene in only 8 of 80 families. In 12 families, we detected some degree of diffuse or nodular goiter; three out of 12 families showed thyroid function impairment and in five of 12 families there were positive prechlorate discharge tests. Eight families that showed mutation had normal temporal bone scan. This investigation, demonstrated that the SLC26A4 gene mutation is the most prevalent syndromic hereditary hearing loss in Iran, a finding in accordance with reports from other countries

Indication and surgical consideration of cochlear implantation at Ramathibodi Hospital.

OBJECTIVES: To demonstrate selection criteria for cochlear implant candidates as well as the outcome of quality of life (QoL) after cochlear implant surgery. MATERIAL AND METHOD: Retrospective review was performed of all cochlear implants at Ramathibodi Hospital. A total number of 33 cochlear implantations were performed during the period of 10 years from December 1995 to December 2005. Inclusion criteria were established and the audiological criteria were then evaluated using the electrical promontory stimulation test. The etiology of severe sensory neural hearing loss was detected. The CT scan and MRI of the inner ear were studied in the different causes of deafness. RESULTS: The main cause of deafness in the present study (16 adults and 17 children) was suffering from pregnancy rubella. The second one was familial congenital deafness. The CT scan studied in the rubella cases showed anatomical normal cochlea and the hereditary cause of deafness showed abnormal cochlea that caused a strong perilymphatic gusher in a 14 year- old boy. There were 16 cases of adolescent and adult patients who all had good response in the promontory stimulation test. The QoL post implantation was evaluated in regards to improvement in education and communication. CONCLUSION: Multi-channel cochlear implantation in severe profound hearing loss patients could improve the hearing in both normal and abnormal cochlea, congenital rubella deafness and the familial cause of deafness. The outcomes of the QoL after surgery were better in hearing detection, speech perception, school performance, communication and return to work.

Genética molecular da deficiência auditiva não-sindrômica / Molecular genetics of non-syndromic deafness

Aproximadamente 1/1000 recém-nascidos apresentam deficiência auditiva congênita, sendo 60 por cento dessas de etiologia genética. Na maioria dos casos, a deficiência auditiva é uma doenca multifatorial causada por ambos os fatores, genéticos e ambientais. A genética molecular da deficiência auditiva tem apresentado grandes avancos na última década, pois os genes responsáveis pela deficiência auditiva hereditária vêm sendo progressivamente mapeados e clonados. Esta revisão enfatiza a deficiência auditiva não-sindrômica, uma vez que, os genes envolvidos nesse tipo de deficiência foram identificados recentemente.

Clinical study and genetics of non syndromic congenital deafness

Hearing impairment affects 1/1000 infants. Congenital deafness is inherited or apparently sporadic. DFNB1 on chromosome 13 is a major locus for recessive deafness in about 80% of Mediterranean families and the connexin-26 gene gap junction protein b2 [GJB2] is mutated in DFNB1 families. We acquired DNA samples from 38 families of Moroccan children with recessive non-syndromic deafness and 95 unrelated participants with apparently sporadic congenital deafness. Therefore, we analysed the coding region of the GJB2 gene for mutations. Findings: 31.5% of participants with recessive deafness and 21.5% of sporadic deafness had mutations in the GJB2 gene. The 35delG mutation represented 24.1% of GJB2 mutations. GJB2 gene mutation is a major cause of inherited congenital deafness. 35delG mutation is the most common mutation for inherited congenital deafness. This study shows that 35delG mutation prevalence is important in Morocco with a prevalence of 31.5%, while it is inexistent in Asian population, and very rare in Africa [2.2%]. Such prevalence disparity may reflect an anthropological history of human travels. So, 35delG mutation has a Mediterranean origin. In conclusion, the mutation in the connexion-26 GJB2 gene is the most common cause of non syndromic autosomal recessive deafness in Morocco. More studies are needed to confirm these findings

Hereditary non-syndromic hearing loss: influence of different variables

Non-syndromic hearing loss [NSHL] was studied in twenty-five patients using a clinical, audiological, cytogenetic and neurobiochemical evaluation. The study group was divided into five subgroups according to severity of hearing loss. Positive parental consanguinity was present in 84% of cases and similarly affected family members were present in 76%. All patients had no congenital malformations and were not dysmorphic. Patients possibly exposed to environmental factors were excluded from the study. Abnormal karyotyping was present in three cases, one case showed chromosome 15p 4, another case showed chromosomal del 11q22.1 and in the third case [47,XY] there was marker chromosome 15. Fluorescence in situ Hybridization [FISH] technique was performed on the case which showed marker. The study group showed significant lowering of five plasma amino acid levels [glutamic acid, aspartic acid, histidine, 3-methylhistidine and carnosine]. There was significant correlation between severity of hearing loss and each of the following: patient's age, glutamic acid, aspartic acid, 3-methylhistidine and carnosine. Identification of NSHL early after birth, as well as, amino acid screening is essential, to allow for faster therapeutic intervention and proper genetic counseling

La sordera congénita en México / Congenital deafness in Mexico

Objetivo: contribuir a definir a la sordera congénita (SC) como problema de salud pública para actualizar sus políticas de prevención y control en México. Se discute su definición, etiología, diagnóstico y clasificación; así como la utilidad de los estudios sobre la respuesta acústica del tallo cerebral, emisiones otoacústicas y la audiometría en el diagnóstico del problema auditivo. Se comenta la información disponible sobre la frecuencia de la SC en México. En la experiencia clínica del Instituto Nacional de la Comunicación Humana al parecer el problema está en ascenso de acuerdo a un período estudiado de 5 años (37.2 vs 52 por ciento). La explotación de un grupo de sordomudos mexicanos en la ciudad de Nueva York, entre otros es comentada como ejemplo de la trascendencia social de la SC. Se comentan los resultados de algunos programas preventivos en otros países que han logrado coberturas de 95 por ciento de todos los recién nacidos y detectado a 100 por ciento de la SC, y otros que han evaluado el impacto de la inmunización contra la rubéola y la parotiditis en la disminución de la prevalencia de la SC. Se concluye que es conveniente completar la definición de la SC como problema de salud pública en México. Para lo cual es necesario promover, ejecutar y evaluar estudios epidemiológicos, cuyos resultados contribuyan a actualizar las políticas de salud y sus consecuentes programas en beneficio de las personas con SC en el país.

Severe congenital hypoacusia in a patient with mosaic ring chromosome 7

Hipoacusia severa congénita en un paciente con mosaico del cromosoma siete en anillo. Introducción. Los cromosomas en anillo son aberraciones cromosómicas que pueden encontrarse como hallazgo en pacientes con talla baja, dismorfias menores e inteligencia normal. Los anillos del cromosoma 7 son raros. Los allazgos mas frecuentes en estos casos incluyen: talla baja, microcefalia y alteraciones dermatológicas. Caso Clínico. En este artículo presentamos a un niño con mosaico del cromosoma siete en anillo, quien tuvo hipoacusia y manchas hiprómicas en la piel. Presentó otras manifestaciones clínico similares a las descritas previamente en pacientes con la misma aberración cromosómica: talla, peso y perímetro cefálico bajos, retraso mental, anomalías dermatológicas y algunas dismorfias. Discusión. Aunque la mayoría de las manifestacione presente en este paciente se han descrito con anterioridad, este es el primer caso en el que se encuentra hipoacusia, y el segundo con manchas hipocrómicas. Nosotros proponemos que esta manifestación dérmica quede incluida entre la variabilidad de expresiones dermatológicas del cromosoma siete en anillo. Además, recomendamos realizar búsqueda intencionada de alteraciones auditivas en pacientes con anomalías de cromosoma siete que involucren regiones subteloméricas

Waardenburg's syndrome case report and review of the literature

A case of Waardenburg syndrome [WS] is described in a 16 year old boy who presented with hetero-chromic irides, congenital deafness, white forelock and piebaldism like hypopigmented macules on dorsum of this hands, forearms and upper right chest since birth

Electrocardiographic changes following exercise in the congenitally deaf school children: relationship with Jervell Lange Neilsen syndrome (the Long QT syndrome).

The present study was conducted to test the effects of exercise stress on the ECG of the congenitally deaf children from school for deaf, in view of the occurrence of the Jervell-Lange Neilsen (Surdo Cardiac) variant of the Long QT Syndrome (LQTS) in them. An ECG Lead II was recorded at rest and after two minutes of static jogging. For comparison, the same protocol was repeated in normal healthy children from another school. ECG were analysed for the calculation of corrected QT interval (QTc) by Bazett's equation QTc = QT/square root of R-R and also for the evidence for other abnormalities. Both in the normal and deaf children, exercise did not produce significant (P > 0.05) change in QTc from their resting values. However, when pre and post exercise QTc values of deaf children were compared with normal children, the female deaf had significantly longer QTc (P < 0.01) both at rest and after exercise than normal female children. Normal children did not show significant ECG abnormality either at rest or on exercise. On the contrary many of their counter part (deaf) exhibited occasional ECG abnormality at rest but plethora of abnormalities after exercise viz., sinus arrhythmias, sinus pauses, ST depression, T-inversion, biphasic-T, notched-T, T-alternans, nodal ectopics and junctional rhythm. These results lend credence to the hypothesis of sympathetic imbalance and repolarisation defects in deaf children's heart, which in more severe form could pass into frank Jervell-Lange Neilsen variant of the Long: QT Syndrome.

Estudio descriptivo: "Momento del período gestacional en que ocurre la rubeola materna y las secuelas que deja el virus rubeólico" Rosario, 1980-1996 / Description study: \"moment of the pregnancy period in that occur the maternal rubella and the secuelas that let go the virus rubella\". Rosario, 1980-1996

El presente estudio de tipo descriptivo, de corte transversal y retrospectivo tuvo como objetivo estudiar las secuelas más frecuentes concomitantes con la hipoacusia debido al virus rubeólico congénito, según la edad gestacional al contagio. La población investigada estuvo compuesta por 52 niños con hipoacusia que concurrieron a 3 Consultorios Fonoaudiológicos y 2 Escuelas de Sordos de la ciudad de Rosario. Se recolectaron los datos de fuentes secundarias: historias clínicas y legajos de los niños. Se comprobó que en el 50 por ciento de los niños la edad gestacional al contagio ocurrió entre el primer y segundo mes. De la población estudiada 31 niños (60,8 por ciento) presentaron hipoacusia de grado profundo, 15 niños (29,4 por ciento) hipoacusia severa y 5 niños (9,8 por ciento) hipoacusia moderada. 23 niños presentaron una o más secuelas concomitantes con la hipoacusia y en 29 niños (55,8 por ciento) la hipoacusia era la única secuela; de ellos en 18 niños el grado de la hipoacusia fue profundo. El tipo de secuela más frecuente con la hipoacusia fue la secuela visual observada en 13 niños (25 por ciento) y la secuela cardíaca en 11 niños (21 por ciento). 17 de los 52 niños que conforman la población en estudio nacieron en el año 1993, después de una epidemia de rubeola en la ciudad de Rosario en el año 1992; todos ellos presentaron algún tipo de secuela además de la hipoacusia. Los resultados anteriores demuestran la importancia del rol del Fonoaudiólogo en la prevención primaria, tratamiento y rehabilitación de niños nacidos con rubéola congénita