Phenotypic characterization of retinitis pigmentosa associated with deafness / Caracterización fenotípica de la retinitis pigmentaria asociada a sordera

Introduction: There are several syndromes that associate retinitis pigmentosa with deafness or hearing loss. The most frequent is Usher syndrome, a genetic disorder of autosomal recessive inheritance, which, in some cases, is accompanied by vestibular dysfunction. However, there are cases of families that despite having retinitis pigmentosa associated with deafness, cannot be classified as Usher or other syndromes due to additional findings. Objective: To reassess the phenotypes of 103 families previously diagnosed as possible Usher syndrome and/or retinitis pigmentosa associated with deafness. Materials and methods: We conducted a descriptive and retrospective study by reviewing the medical records of 103 families with a probable clinical diagnosis of Usher syndrome and/or retinitis pigmentosa associated with deafness. Families whose clinical diagnosis did not correspond to the typical Usher syndrome were selected and evaluated ophthalmologically and audiologically. Demographic and clinical variables were analyzed. Results: We selected and then reevaluated 14 families and 55 individuals as they did not correspond to a clinical diagnosis of Usher syndrome; 13.6% of the families initially considered to have typical Usher syndrome were later diagnosed with retinitis pigmentosa associated with deafness, another ocular symptom associated with hearing loss, retinitis pigmentosa, or isolated hearing loss in the same family. Conclusions: Family studies are essential in cases where the symptoms do not match the typical Usher' syndrome. In the cases of retinitis pigmentosa associated with deafness, a correct clinical diagnosis allows for focusing on the molecular analyses to establish a differential diagnosis. The need for nomenclature guidelines on these atypical findings is relevant to aid physicians and researchers in the best approach to these cases.

Introducción. El síndrome de Usher es una alteración genética caracterizada por la asociación de retinitis pigmentaria y sordera. Sin embargo, hay casos con familias en las cuales, a pesar de presentarse dicha asociación, no se puede diagnosticar un síndrome de Usher ni ninguno otro. Objetivo. Reevaluar fenotípicamente a 103 familias con diagnóstico previo de posible síndrome de Usher o retinitis pigmentaria asociada con sordera. Materiales y métodos. Se revisaron las historias clínicas de 103 familias con un posible diagnóstico clínico de síndrome de Usher o retinitis pigmentaria asociada con sordera. Se seleccionaron las familias cuyo diagnóstico clínico no correspondía a un síndrome de Usher típico. Los afectados fueron valorados oftalmológica y audiológicamente. Se analizaron variables demográficas y clínicas. Resultados. Se reevaluaron 14 familias cuyo diagnóstico clínico no correspondía al de síndrome de Usher. De las familias con diagnóstico inicial de síndrome de Usher típico, el 13,6 % recibieron uno posterior de "retinitis pigmentaria asociada con sordera", de "otro síntoma ocular asociado con hipoacusia", o en forma aislada en una misma familia, de "retinitis pigmentaria" o "hipoacusia". Conclusiones. Es fundamental el estudio familiar en los casos en que la clínica no concuerda con el diagnóstico de síndrome de Usher típico. En los pacientes con retinitis pigmentaria asociada con sordera, el diagnóstico clínico acertado permite enfocar los análisis moleculares y, así, establecer un diagnóstico diferencial. Es necesario elaborar guías de nomenclatura en los casos con estos hallazgos atípicos para orientar a médicos e investigadores en cuanto a su correcto manejo.

Caracterización fenotípica de la retinitis pigmentaria asociada a sordera / Phenotypic characterization of retinitis pigmentosa associated with deafness

Introducción. El síndrome de Usher es una alteración genética caracterizada por la asociación de retinitis pigmentaria y sordera. Sin embargo, hay casos con familias en las cuales, a pesar de presentarse dicha asociación, no se puede diagnosticar un síndrome de Usher ni ninguno otro. Objetivo. Reevaluar fenotípicamente a 103 familias con diagnóstico previo de posible síndrome de Usher o retinitis pigmentaria asociada con sordera. Materiales y métodos. Se revisaron las historias clínicas de 103 familias con un posible diagnóstico clínico de síndrome de Usher o retinitis pigmentaria asociada con sordera. Se seleccionaron las familias cuyo diagnóstico clínico no correspondía a un síndrome de Usher típico. Los afectados fueron valorados oftalmológica y audiológicamente. Se analizaron variables demográficas y clínicas. Resultados. Se reevaluaron 14 familias cuyo diagnóstico clínico no correspondía al de síndrome de Usher. De las familias con diagnóstico inicial de síndrome de Usher típico, el 13,6 % recibieron uno posterior de "retinitis pigmentaria asociada con sordera" de "otro síntoma ocular asociado con hipoacusia',' o en forma aislada en una misma familia, de "retinitis pigmentaria" o "hipoacusia'.' Conclusiones. Es fundamental el estudio familiar en los casos en que la clínica no concuerda con el diagnóstico de síndrome de Usher típico. En los pacientes con retinitis pigmentaria asociada con sordera, el diagnóstico clínico acertado permite enfocar los análisis moleculares y, así, establecer un diagnóstico diferencial. Es necesario elaborar guías de nomenclatura en los casos con estos hallazgos atípicos para orientar a médicos e investigadores en cuanto a su correcto manejo.

Introduction: There are several syndromes that associate retinitis pigmentosa with deafness or hearing loss. The most frequent is Usher syndrome, a genetic disorder of autosomal recessive inheritance, which, in some cases, is accompanied by vestibular dysfunction. However, there are cases of families that despite having retinitis pigmentosa associated with deafness, cannot be classified as Usher or other syndromes due to additional findings. Objective: To reassess the phenotypes of 103 families previously diagnosed as possible Usher syndrome and/or retinitis pigmentosa associated with deafness. Materials and methods: We conducted a descriptive and retrospective study by reviewing the medical records of 103 families with a probable clinical diagnosis of Usher syndrome and/or retinitis pigmentosa associated with deafness. Families whose clinical diagnosis did not correspond to the typical Usher syndrome were selected and evaluated ophthalmologically and audiologically. Demographic and clinical variables were analyzed. Results: We selected and then reevaluated 14 families and 55 individuals as they did not correspond to a clinical diagnosis of Usher syndrome; 13.6% of the families initially considered to have typical Usher syndrome were later diagnosed with retinitis pigmentosa associated with deafness, another ocular symptom associated with hearing loss, retinitis pigmentosa, or isolated hearing loss in the same family. Conclusions: Family studies are essential in cases where the symptoms do not match the typical Usher' syndrome. In the cases of retinitis pigmentosa associated with deafness, a correct clinical diagnosis allows for focusing on the molecular analyses to establish a differential diagnosis. The need for nomenclature guidelines on these atypical findings is relevant to aid physicians and researchers in the best approach to these cases.

An update on Fanconi anemia: Clinical, cytogenetic and molecular approaches (Review).

Fanconi anemia is a genetic syndrome clinically characterized by congenital malformations that affect several human systems, leads to progressive bone marrow failure and predisposes an individual to cancer, particularly in the urogenital area as well as the head and neck. It is commonly caused by the biallelic compromise of one of 22 genes involved in the FA/BRCA repair pathway in most cases. The diagnosis is based on clinical suspicion and confirmation using genetic analysis, where the chromosomal breakage test is considered the gold standard. Other diagnostic methods used include western blotting, multiplex ligation-dependent probe amplification and next-generation sequencing. This genetic condition has variable expressiveness, which makes early diagnosis difficult in certain cases. Although early diagnosis does not currently allow for improved cure rates for this condition, it does enable healthcare professionals to perform a specific systematic follow-up and, if indicated, a bone marrow transplantation that improves the mobility and mortality of affected individuals. The present review article is a theoretical revision of the pathophysiology, clinical manifestations and diagnosis methods intended for different specialists and general practitioners to improve the diagnosis of this condition.

CNVs in the 22q11.2 Chromosomal Region Should Be an Early Suspect in Infants with Congenital Cardiac Disease.

BACKGROUND: Congenital heart disease (CHD) is the most common congenital malformation, it is frequently found as an isolated defect, and the etiology is not completely understood. Although most of the cases have multifactorial causes, they can also be secondary to chromosomal abnormalities, monogenic diseases, microduplications or microdeletions, among others. Copy number variations (CNVs) at 22q11.2 are associated with a variety of symptoms including CHD, thymic aplasia, and developmental and behavioral manifestations. We tested CNVs in the 22q11.2 chromosomal region by MLPA in a cohort of Colombian patients with isolated CHD to establish the frequency of these CNVs in the cohort. METHODS: CNVs analysis of 22q11.2 by MLPA were performed in 32 patients with apparently isolate CHD during the neonatal period. Participants were enrolled from different hospitals in Bogotá, and they underwent a clinical assessment by a cardiologist and a clinical geneticist. RESULTS: CNVs in the 22q11.2 chromosomal region were found in 7 patients (21.9%). The typical deletion was found in 6 patients (18.75%) and atypical 1.5 Mb duplication was found in 1 patient (3.1%). CONCLUSIONS: CNVs in 22q11.2 is a common finding in patients presenting with isolated congenital cardiac disease, therefore these patients should be tested early despite the absence of other clinical manifestations. MLPA is a very useful molecular method and provides an accurate diagnosis.

Encefalopatía epiléptica infantil en un paciente colombiano con una variante patogénica de novo en el gen STXBP1 / Infantile epileptic encephalopathy in a colombian child with a pathogenic de novo STXBP1STXBP1gene variant

El desarrollo de los estudios moleculares ha permitido identificar la etiología genética de diversas enfermedades como las encefalopatías epilépticas infantiles, las cuales se han asociado con variantes patogénicas en diferentes genes, entre ellos el STXBP1. La encefalopatía con epilepsia STXBP1 es una enfermedad genética con un patrón de herencia autosómico dominante, donde están alterados los mecanismos reguladores de la liberación de neurotransmisores por parte de las vesículas sinápticas, con alteración del neurodesarrollo. La edad de presentación del trastorno es temprano, con convulsiones en los primeros dos meses de vida. Los pacientes presentan dificultades en la alimentación, trastornos del movimiento y alteración del espectro autista. En este artículo presentamos el caso clínico de un paciente colombiano con encefalopatía epiléptica STXBP1 revisando los aspectos clínicos de la enfermedad, dirigido a profesionales de la salud para sensibilizarlos y así lograr el diagnóstico temprano. Esta es la primera publicación en el país de un paciente con esta etiología

The development of molecular studies has allowed identifying the genetic cause of various diseases such as infantile epileptic encephalopathy. Several pathogenic variants of different genes have been implicated including the STXBP1 gene. STXBP1 encephalopathy with epilepsy is inherited in an autosomal dominant pattern with disrupted liberation of regulatory mechanisms of neurotransmitters in the synaptic vesicles associated with neurodevelopmental impairments. This condition is characterized by early onset with seizures in the first two months of life. Affected patients may have eating problems, movement disorders and autism spectrum disorders. Herein we present a case of a Colombian infant with STXBP1 encephalopathy with epilepsy. We describe the clinical aspects of the disease to sensitize health care professionals for them to identify this condition and achieve an early diagnosis. This is the first publication in Colombia on a patient featuring this type of etiology.