Prepubertal gynecomastia: a rare manifestation of myotonic dystrophy type 1 / Ginecomastia pré-púbere: uma manifestação rara da distrofia miotônica tipo 1

ABSTRACT Objective: To present a case of bilateral gynecomastia in a prepubertal boy with autism spectrum disorder, diagnosed with myotonic dystrophy type 1. Case description: A 12-year-old boy with autism spectrum disorder presented at a follow-up visit with bilateral breast growth. There was a family history of gynecomastia, cataracts at a young age, puberty delay, and myotonic dystrophy type 1. The physical examination showed that he had bilateral gynecomastia with external genitalia Tanner stage 1. Neurologic examination was regular, without demonstrable myotonia. The analytical study revealed increased estradiol levels and estradiol/testosterone ratio. After excluding endocrine diseases, the molecular study of the dystrophia myotonica protein kinase gene confirmed the diagnosis of myotonic dystrophy type 1. Comments: A diagnosis of prepubertal gynecomastia should include an investigation for possible underlying diseases. This case report highlights the importance of considering the diagnosis of myotonic dystrophy type 1 in the presence of endocrine and neurodevelopmental manifestations.

RESUMO Objetivo: Apresentar o caso de um adolescente pré-púbere com ginecomastia bilateral e transtorno do espectro autista, diagnosticado com distrofia miotônica tipo 1. Descrição do caso: Adolescente do sexo masculino de 12 anos, com transtorno do espectro autista, observado em consulta de seguimento por crescimento mamário bilateral. O paciente tinha antecedentes familiares de ginecomastia, catarata em idade jovem, atraso pubertário e distrofia miotônica tipo 1. À observação física, apresentava ginecomastia bilateral estádio 1 de Tanner. O exame neurológico era normal, sem miotonia aparente. O estudo analítico mostrou níveis elevados de estradiol e da relação estradiol/testosterona. Após exclusão de causas endócrinas, o estudo molecular do gene DMPK confirmou o diagnóstico de distrofia miotônica tipo 1. Comentários: Perante um quadro de ginecomastia pré-púbere, deve-se excluir doenças subjacentes. Este caso reforça a importância de considerar o diagnóstico de distrofia miotônica tipo 1 na presença de manifestações endócrinas e do neurodesenvolvimento.

Taquicardia ventricular como expresión de distrofia miotónica tipo 1 / Type I myotonic dystrophy presenting with ventricular tachycardia

Abstracts: A 48-year-old woman was brought to the emergency room with ventricular tachycardia that was eventually terminated by cardioversion. Clinical and neurologic evaluation, including electromyography were highly suggestive of type I Myotonic Dystrophy and genetical studies confirmed the diagnosis. A discussion about the diagnostic procedures and management of the disease, especially the associated ventricular tachycardia, is included.

Múltiplas causas de síncope em pacientes com distrofia miotônica tipo I / Multiple causes of syncope in patients with myotonic dystrophy type I

A distrofia miotônica é a doença neuromuscular mais frequente na população adulta. Embora tenha caráter multissistêmico, apresenta especial predileção pelo sistema de condução cardíaco, manifestando-se tanto com bloqueios atrioventriculares como com taquiarritmias ventriculares e supraventriculares. O foco deste trabalho é apresentar, através do relato de um caso, a importância de uma investigação mais detalhada dos casos de síncope em pacientes portadores de distrofia miotônica, pois alterações inaparentes e potencialmente graves podem passar despercebidas

Myotonic dystrophy is the most frequent neuromuscular disease in the adult population. Although it is a multisystem disease, it usually has a special preference for the cardiac conduction system manifesting itself as atrioventricular conduction block and as ventricular and supraventricular tachyarrhythmias. The focus of this work is to use a case report to demonstrate the importance of a more detailed investigation of syncope in patients with myotonic dystrophy, since unapparent and potentially serious changes may go by unnoticed

Distrofa miotónica congénita en una Unidad de Cuidados Intensivos Neonatales: serie de casos / Congenital myotonic dystrophy in a Neonatal Intensive Care Unit: case series

La distrofia miotónica de Steinert es una enfermedad multisistémica, autosómica dominante, con un amplio espectro de gravedad y manifestaciones clínicas. La forma más grave es aquella que se manifesta en el periodo neonatal, llamada distrofa miotónica congénita. Se destaca la hipotonía global al nacer y el compromiso de la función respiratoria. Las complicaciones son frecuentes, principalmente, retraso del desarrollo psicomotor, del crecimiento pondoestatural, difcultades alimentarias y constipación. Se asocia a un mal pronóstico, con una mortalidad global de hasta un 50% de los niños gravemente afectados. Presentamos cinco casos de distrofa miotónica congénita con el objetivo de describir manifestaciones clínicas, métodos diagnósticos, tratamiento y pronóstico. Los datos existentes en la literatura sobre el desarrollo psicomotor, complicaciones y pronóstico de los supervivientes con distrofa miotónica congénita son pocos. En nuestra serie de casos, las limitaciones psicomotoras presentadas son signifcativas.

Steinert myotonic dystrophy is a multisystemic disease, autosomal dominant, with a wide spectrum of severity and clinical manifestations. The most severe form is one that manifests in the neonatal period, called congenital myotonic dystrophy. This condition is distinguished by overall hypotonia at birth and respiratory function compromise. Complications are frequent, mainly psychomotor development delay, growth failure, food diffculties and constipation. It is associated with a poor prognosis, with an overall mortality of up to 50% of severely affected children. We present fve patients with congenital myotonic dystrophy in order to describe clinical manifestations, diagnosis, treatment and prognosis. Existing data in the literature on psychomotor development, complications and prognosis of survivors withcongenital myotonic dystrophy are scarce. In our case studies, we have found signifcant chronic psychomotor limitations.

Efectos orales y en la articulación temporomandibular del fenómeno de anticipación en pacientes con distrofia muscular de Steinert / Oral effects and also in the temporomandibular joint for the anticipatory phenomenon in patients with Steinert's muscular dystrophy

La distrofia muscular de Steinert tipo 1 afecta frecuentemente a los músculos de la masticación y puede causar debilidad muscular y alteraciones bucofaciales. Esta enfermedad se caracteriza por presentar el fenómeno de anticipación, en el cual la descendencia de una persona afectada desarrolla la enfermedad de manera más precoz. El objetivo de este trabajo fue reportar 2 casos de una madre y su hija con diagnóstico de distrofia muscular de Steinert. Se realizó un análisis de las características clínicas bucales y los efectos del fenómeno de anticipación de esta enfermedad mediante el examen odontológico, la medición de la fuerza masticatoria y la resonancia magnética nuclear de la articulación temporomandibular. La expresión clínica de la enfermedad fue más precoz en la hija que en la madre, lo que se relacionó con un mayor número de estructuras dentarias perdidas y de cambios degenerativos en la articulación temporomandibular, asociados a una menor fuerza masticatoria(AU)

ABSTRACT The Steinert's muscular dystrophy type 1 involves frequently the masticatory muscle causing muscular weakness and orofacial alterations; this entity is characterized by to present the anticipatory phenomenon where la offspring of a involved person develops the disease in an early way. The aim of present paper is to report 2 cases in mother and daughter diagnosed with the DM1 and to analyze the oral clinical features and the effects of anticipatory phenomenon of disease by stomatologic examination, measurement of masticatory strength and magnetic nuclear resonance of temporomandibular joint. The clinical expression of this disease was earlier in the daughter than in the mother, which was related to a greater number of lost teeth and of degenerative changes en la TMJ associated with a lesser masticatory strength(AU)

Distrofia miotônica de Steinert e hipersonia primária: relato de caso / Myotonic dystrophy of Steinert and primary hypersomnia: case report

Este artigo apresenta o caso de uma paciente com distrofia miotônica tipo 1 (DM1) (doença de Steinert) e faz a revisão de literatura sobre sonolência excessiva diurna (SED) nestes pacientes. Paciente de 36 anos, portadora de (DM1), apresenta SED e testes múltiplos de latência com média de latências de 1 minuto e 22 segundos. DM1 e SED podem ter várias etiologias, a ressaltar as devidas à disfunção no sistema nervoso central ou à miopatia. No caso da paciente, provavelmente predomina a SED de origem central.

This article presents the case of a myotonic dystrophy type 1 - Steinert's disease (DM1) patient and reviews the literature on excessive daytime sleepiness (EDS) in these patients. Patient of 36 years of age, with DM1, presents EDS and mean multiple sleep latency test of 1 minute and 22 seconds. DM1 and EDS can have some etiologies, mainly due to central nervous system dysfunction or to the myopathy. In the present case, probably predominate the SED of central origin.

Enfermedad de Steinert y embarazo: caso clínico / Steinert's disease and pregnancy: a case report

La enfermedad de Steinert es una enfermedad genética que se hereda con un patrón autosómico dominante, resultado de la expansión de la repetición de trinucleótidos CTG gen en el cromosoma 19, que codifica una proteína quinasa. Es una forma grave de distrofia muscular caracterizada por debilidad generalizada y degeneración muscular. El debut puede ocurrir en cualquier momento desde el nacimiento hasta la edad madura. Las complicaciones durante el embarazo son el aborto espontáneo, parto prematuro, el hidramnios, atonía uterina posparto, distocias intraparto y accidentes anestésicos. Presentamos el caso de una gestante de 37 años, asintomática con una anamnesis familiar sin patología de interés. Fue diagnosticada de diabetes gestacional y polihidramnios inespecífico en la semana 30 de embarazo. Acudió a nuestro centro en semana 35 de gestación por dinámica uterina y metrorragia. Se realizó una cesárea extrayéndose un feto masculino, con graves dificultades respiratorias y miotonía generalizada. Posteriormente, el neonato fue diagnosticado de enfermedad congénita de Steinert. El análisis genético de la madre reveló que ella padecía la misma enfermedad. El diagnóstico de enfermedad congénita de Steinert es muy difícil, sobretodo cuando los padres no son conscientes de la enfermedad. Nuestro objetivo es enfatizar en la importancia de una buena anamnesis y los marcadores que se pueden encontrar por ultrasonidos, como hidramnios, reducción del tono fetal y los movimientos activos, artrogriposis, micrognatia, que nos puede proporcionar al menos una sospecha prenatal.

Steinert's disease is a genetic condition, which is inherited in an autosomal dominant pattern, result from expansion of CTG trinucleotide repeat gene on chromosome 19, enconding a putative protein kinase. It is a severe form of muscular dystrophy marked by generalised weakness and muscular wasting. The onset can be any time from birth to middle age. The complications during pregnancy are miscarriage, premature labour, hydramnios, atonic postpartum hemorrhage, difficulties during delivery, anesthetic accidents. We report the case of a healthy 37 years old pregnant, with an ordinary family anamnesis. She was diagnosed of gestational diabetes and inespecific polyhydramnios during her 30 week of pregnancy. Due to labour contractions and metrorrhagia in the 35 week she came to our emergency department. She underwent a cesarean section delivery of a male baby, who suffered severe breathing difficulties and generalized myotonia. Afterwards, the baby was diagnosticated with Steinert's congenital disease. Following genetic analysis of the mother revealed that she also suffers Steinert's disease. The diagnosis of the congenital Steinert's disease is really difficult, when the parents are unaware of the disease. Our objective is to emphasize in the importance of a good anamnesis and the characters that can be found out by ultrasound like hydramnios, reduction of fetal tone and active movements, micrognathia, arthrogryposis, that can bring us at least to a prenatal suspicion.

Distrofia miotónica tipo I (enfermedad de steinert) y embarazo: descripción de un caso clínico / Myotonic distrophy type I (steinert disease) and pregnancy: a clinical case description

Type I myotonic dystrophy or Steinert's disease (DM1, OMIM 160900), is an autosomal dominant mulsystem disease of variable expresión caused by a (CTG)n, expansion mutation in the gene encoding for the myotonic dystrophy protein kinase (DMPK) in 19ql3. The disease is characterized by a phenomenon of anticipation, resulting in a more severe expression of the disease in successive generations, in correlation with the size of the triplet expansion. The congenital form of the disease, ussually of maternal transmisión, may cause polyhidramnios, foetal or neonatal death, or a sever neonatal floppy infant syndrome charaterized by facial diplegia, dysphagia, respiratory distress syndrome and a variable degree of mental retardation in 60 percent of the cases. The aim of this report is to describe a DM1 affecting a 35 years old woman and her fetus of 28 weeks of gestation at the moment of diagnosis. We describe the evolution of the pregnancy and her neonate, we discuss the reciprocal influence between pregnancy and the disease, enhacing the antenatal and neonatal complications.

La distrofia miotónica de Steinert o tipo I (DM1, OMIM 160900), es una enfermedad multisistémica, autosómica dominante de penetrancia variable, causada por la expansión del tupíete (CTG)n, en el gen que codifica para la proteína kinasa de la distrofia miotónica (DMPK) en el cromosoma 19ql3. La enfermedad se caracteriza por un fenómeno de anticipación, producto del cual su expresión es mayor en generaciones sucesivas y correlaciona con la talla de la expansión. La forma congénita de la enfermedad, habitualmente de transmisión materna puede producir polthidramnios, muerte fetal o neonatal o un síndrome hipotónico neonatal severo con diplegia facial, disfagia, distress respiratorio y retardo mental de grado variable en un 60 por ciento de los casos. El presente reporte tiene por objeto comunicar un caso de DM1 en una mujer de 35 años y en su feto de 28 semanas de gestación al momento del diagnóstico. Describimos la evolución del embarazo y del neonato, se discute la influencia recíproca entre la enfermedad y el embarazo, con énfasis en las complicaciones antenatales y neonatales.

Molecular and Clinical Characteristics of Myotonic Dystrophy Type 1 in Koreans / 대한진단검사의학회지

BACKGROUND: Myotonic dystrophy type 1 (DM1) is an autosomal-dominant muscular dystrophy caused by expansion of cytosine-thymine-guanine (CTG) trinucleotide repeats in the myotonic dystrophy protein kinase (DMPK) gene. The clinical features of DM1 are multisystemic and highly variable, and the unstable nature of CTG expansion causes wide genotypic and phenotypic presentations. The aim of this study was to characterize the molecular and clinical spectra of DM1 in Koreans. METHODS: The CTG repeats of 283 Korean individuals were tested by PCR fragment analysis and Southern blot. The following characteristics were assessed retrospectively: spectrum of CTG expansions, clinical findings, genotype-phenotype correlation, anticipation, and genetic instability. RESULTS: One-hundred twenty-four patients were confirmed as DM1 by molecular tests, and the CTG expansions ranged from 50 to 2,770 repeats (median 480 repeats). The most frequent clinical features were myotonia, muscular weakness, and family history. Patients with muscular weakness or dysfunction of the central nervous system harbored larger CTG expansions than those without each symptom (P<0.05). The age of onset was inversely correlated with the size of the CTG expansion (gamma=-0.422, P<0.001). The instability of CTG expansion representing as the maximum difference between sibships was observed from 50 to 700 repeats in nine families. Clinical anticipation and the increase in CTG repeat were significantly higher in maternally transmitted alleles (P=0.002). CONCLUSIONS: Molecular genetic tests are not only essential for diagnosis, but also helpful for suggesting the spectrum and relationship between genotype and phenotype in Korean DM1 patients.

Myotonic dystrophy with pregnancy.

Myotonic dystrophy is a rare heredodegenerative muscular disorder in which pregnancy is unusual. Because of the autosomal dominant inheritance of the disease, 50% of children of an affected parent may have the disease; 20% of them are asymptomatic at birth. Foetal involvement may be manifested by polyhydramnios, arthrogryposis multiplex in utero, respiratory difficulties, and floppiness at birth. A case of myotonic dystrophy with pregnancy is presented here.

(CTG)n expansion at DMPK locus seen only in muscle tissue: a novel case.

Triplet repeat expansion in 3 untranslated region of myotonic dystrophy protein kinase (DMPK) gene has been implicated as causative in myotonic dystrophy (DM). In cases of DM, high levels of somatic instability have been reported, in which inter-tissue repeat length differences as large as 3000 repeats have been observed. This study highlights the inter-tissue (CTG)n expansion variability at the DMPK locus. Molecular analysis of DMPK gene, encompassing the triplet repeat expansion, was carried out in 31 individuals (11 clinically identified DM patients, 20 controls). All controls showed a 2.1kb band (upto 35 CTG repeats), while four cases exhibited an expansion (>50 repeats). A novel observation was made in one case, wherein the DNA from lymphocytes showed a normal 2.1kb band while the muscle tissue DNA from the same patient was heterozygous for normal and 4.3 kb band (>700 repeats). Our results suggested that because inter-tissue variability existed in the (CTG)n repeat number at DMPK locus, an attempt should be made to evaluate affected tissue along with blood wherever possible prior to making a final diagnosis. This is important not only for diagnosis and prenatal analysis, but also while providing genetic counseling to families.

Disabilities caused by unstable mutations in Costa Rica

Myotonic dystrophy and fragile X syndrome are two genetically determined relatively common disabilities. Both are examples of a new type of mutation mechanism called unstable or dynamic mutations, triple repeats expansions or DNA amplification. Fragile X syndrome is recognized as the main cause of hereditary mental retardation and myotonic dystrophy is considered the most common muscular dystrophy of adults. This is a prospective non randomized study of clinically affected people, in order to confirm the diagnosis with molecular techniques (Southern blot and PCR) and to perform cascade screening of the rest of the family to offer them adequate genetic counseling. We were able to corroborate the initial diagnosis in most clinical cases of myotonic dystrophy, but in the cases of mental retardation more than half studies were negative for fragile X syndrome, stressing the difficulties encountered by medical practitioners to diagnose this syndrome. The reasons for this are several; probable the main culprit is the subtle and unspecific clinical picture affected individuals exhibit, particularly children before puberty. Cascade screening, genetic counseling and selective abortion are the only tools available to prevent these disabling diseases for the moment.

Diagnóstico molecular de la distrofia miotónica (DM) en Costa Rica / Molecular diagnostic of the myotonic dystrophy (MD) in Costa Rica

La Distrofía Miotónica es una enfermedad multisistémica de herencia autosómica dominante. El defecto molecular es una expansión del trinucleótico CTG presente en la región 3`no codificante (3ÙTR) del gen DMPK, localizado en el cromosoma 19q13.3. El objetivo del estudio fue implementar el diagnóstico molecular de la DM con el fin de contribuir a mejorar el manejo clínico de los pacientes afectados y a que el consejo genético sea más certero y preciso. El estudio se realizó en pacientes con diagnóstico clínico de DM y sus familiares, a los cuales se les confirmó el diangóstico mediante el uso de técnicas moleculares, a saber, la hibridación de Southern y la PCR. Se obtuvo el diagnóstico molecular de 84 pacientes de 21 diferentes familias; en 34 se diagnosticó el defecto molecular. En 21 personas de familias no se encontró la mutación. Se observó una correlación positiva entre la severidad de la enfermedad y el número de repeticiones CTG. Aquellos casos que resultaron negativos probablemente sean pacientes con mutaciones en otros genes, ya sea PROMM/DM2 u otras miotonias hereditarias. El diagnóstico molecular debe usarse como herramienta para lograr la clasificación clínica de los pacientes. El abordaje correcto de la enfermedad debido a que todavía no existe tratamiento, debe incluir, además del manejo clínico interdisciplinario, la prevención mediante el consejo genético basado en el diagnóstico molecular preciso de la condición de portador o portadora. Descriptores: Distrofia miotónica, mutaciones inestables, anticipación genética, Costa Rica, Hibridación de Southern, PCR, PROMM, consejo genético

Electrophysiological evaluation in myotonic dystrophy: correlation with CTG length expansion

In myotonic dystrophy (MD), disease severity has been correlated with expansion of CTG repeats in chromosome 19. The aims of this study were to evaluate efficacy of electromyography in the diagnosis of MD, access the frequency and the characteristics of peripheral involvement in the disease and to verify whether the CTG repeats correlated with the electrophysiological abnormalities. Twenty-five patients and six relatives at risk of carrying the MD gene were examined. Electrical myotonia (EM) was scored. Sensory and motor conduction velocity (CV) were studied in five nerves. Leukocyte DNA analysis was done in 26 subjects. Myopathy and myotonia were found in 27 cases. EM was most frequent in muscles of hand and in tibialis anterior. No significant correlation was found between EM scores and length of CTG expansions. EM scores correlated significantly with the degree of clinical myopathy, expressed by a muscular disability scale. Peripheral neuropathy was found in eight subjects and was not restricted to those who were diabetics

Disfagia orofaríngea na distrofia miotônica: avaliaçäo fonoaudiológica e análise nasofibrolaringoscópica / Oropharyngeal dysphagia in the myotonic dystrophy: phonoaudiological evaluation and nasofibrolaryngoscopical analysis

Apresentamos vinte pacientes com distrofia miotônica de Steinert, avaliados entre 1995 e 1999, pela análise fonoaudiológica e nasofibrolaringoscópica, com o objetivo de analisar e classificar as alteraçöes da deglutiçäo orofaríngea e funçöes do sistema estomatognático e considerar os fatores preditivos. A idade dos pacientes variou de 12 a 53 anos; 13 eram do sexo masculino e 7 do feminino. Os principais achados foram: (1) há relaçäo estatisticamente significante entre avaliaçäo fonoaudiológica e nasofibrolaringoscópica; (2) foram observadas alteraçöes do sistema estomatognático, em 100 por cento dos casos; (3) foram registradas alteraçöes de deglutiçäo em 95 por cento dos pacientes, à avaliaçäo fonoaudiológica, e em 70 por cento, à nasofibrolaringoscopia; (4) os pacientes têm maior dificuldade para deglutir alimentos consistentes; (5) os músculos estomatognáticos muito alterados, desordem da fase faringeal, tosse após deglutiçäo, antecedentes de pneumonia e queixas de mastigaçäo/ deglutiçäo apresentaram correlaçäo estatisticamente significante com maior gravidade da doença. Foram avaliadas, estática e funcionalmente, estruturas envolvidas na dinâmica da deglutiçäo. Esta avaliaçäo deve constar da rotina do atendimento aos pacientes com distrofia miotônica de Steinert

Aspectos genéticos y moleculares de la distrofía miotónica / Molecular and genetic aspects of myotonic distrophy

La distrofia miotónica es una enfermedad multisistémica, la cual afecta varios tejidos, como el músculo, el cerebro y algunos tejidos endocrinos. Presenta un patrón de herencia autosómico dominante con penetrancia incompleta y expresión variable. El defecto molecular es una expansión del trinucleótido CTG presente en la región 3 no codificante del gen DMPK, el cual codifica para una proteína quinasa. Existe una correlación positiva entre el número de repeticiones del trinocleótido CTG del alelo afectado y la severidad de la enfermedad y una correlación inversa entre la edad de expresión de la enfermedad y la longitud de la repetición. Se presenta inestabilidad de la repetición tanto mitótica como meióticamente, la primera provoca heterogeneidad somática la segunda causa aumento en el número de repeticiones con la trasmisión de padres a hijos. El mecanismo que conlleva a la expansión y su consecuencia a nivel celular no se conocen por el momento, aunque han surgido algunas hipótesis al respecto. La transmisión de la enfermedad en una familia dependerá tanto del sexo del padre que aporte la mutación como del tamaño de la repetición presente en los gametos. La forma congénita de la enfermedad ocurre casi exclusivamente por transmisión materna, mientras que las mutaciones negativas o contracciones ocurren por la vía paterna. Hasta el momento no existe tratamiento para la enfermedad, pues la fisiopatología de la misma no se conoce