Localization in Two-Dimensional Quasicrystalline Lattices.

We investigate the emergence of localization in a weakly interacting Bose gas confined in quasicrystalline lattices with three different rotational symmetries: five, eight, and twelve. The analysis, performed at a mean field level and from which localization is detected, relies on the study of two observables: the inverse participation ratio (IPR) and the Shannon entropy in the coordinate space. Those physical quantities were determined from a robust statistical study for the stationary density profiles of the interacting condensate. Localization was identified for each lattice type as a function of the potential depth. Our analysis revealed a range of the potential depths for which the condensate density becomes localized, from partially at random lattice sites to fully in a single site. We found that localization in the case of five-fold rotational symmetry appears for (6ER,9ER), while it occurs in the interval (12ER,15ER) for octagonal and dodecagonal symmetries.

Multi-institutional experience of genetic diagnosis in Ecuador: National registry of chromosome alterations and polymorphisms.

BACKGROUND: Detection of chromosomal abnormalities is crucial in various medical areas; to diagnose birth defects, genetic disorders, and infertility, among other complex phenotypes, in individuals across a wide range of ages. Hence, the present study wants to contribute to the knowledge of type and frequency of chromosomal alterations and polymorphisms in Ecuador. METHODS: Cytogenetic registers from different Ecuadorian provinces have been merged and analyzed to construct an open-access national registry of chromosome alterations and polymorphisms. RESULTS: Of 28,806 karyotypes analyzed, 6,008 (20.9%) exhibited alterations. Down syndrome was the most frequent autosome alteration (88.28%), followed by Turner syndrome (60.50%), a gonosome aneuploidy. A recurrent high percentage of Down syndrome mosaicism (7.45%) reported here, as well as by previous Ecuadorian preliminary registries, could be associated with geographic location and admixed ancestral composition. Translocations (2.46%) and polymorphisms (7.84%) were not as numerous as autosomopathies (64.33%) and gonosomopathies (25.37%). Complementary to conventional cytogenetics tests, molecular tools have allowed identification of submicroscopic alterations regions or candidate genes which can be possibly implicated in patients' symptoms and phenotypes. CONCLUSION: The Ecuadorian National Registry of Chromosome Alterations and Polymorphisms provides a baseline to better understand chromosomal abnormalities in Ecuador and therefore their clinical management and awareness. This data will guide public policy makers to promote and financially support cytogenetic and genetic testing.

Localisation of weakly interacting bosons in two dimensions: disorder vs lattice geometry effects.

We investigate the effects of disorder and lattice geometry against localisation phenomena in a weakly interacting ultracold bosonic gas confined in a 2D optical lattice. The behaviour of the quantum fluid is studied at the mean-field level performing computational experiments, as a function of disorder strength for lattices of sizes similar to current experiments. Quantification of localisation, away from the Bose glass phase, was obtained directly from the stationary density profiles through a robust statistical analysis of the condensate component, as a function of the disorder amplitude. Our results show a smooth transition, or crossover, to localisation induced by disorder in square and triangular lattices. In contrast, associated to its larger tunneling amplitude, honeycomb lattices show absence of localisation for the same range of disorder strengths and same lattice amplitude, while also exhibiting partial localisation for large disorder amplitudes. We also conclude that the coordination number z have a partial influence on how fast this smooth transition occurs as the system size increases. Signatures of disorder are also found in the ground state energy spectrum, where a continuous distribution emerges instead of a distribution of sharp peaks proper to the system in the absence of disorder.

Novel EYA1 variants causing Branchio-oto-renal syndrome.

INTRODUCTION: Branchio-oto-renal (BOR) syndrome is an autosomal dominant genetic disorder characterized by second branchial arch anomalies, hearing impairment, and renal malformations. Pathogenic mutations have been discovered in several genes such as EYA1, SIX5, and SIX1. However, nearly half of those affected reveal no pathogenic variant by traditional genetic testing. METHODS AND MATERIALS: Whole Exome sequencing and/or Sanger sequencing performed in 10 unrelated families from Turkey, Iran, Ecuador, and USA with BOR syndrome in this study. RESULTS: We identified causative DNA variants in six families including novel c.525delT, c.979T > C, and c.1768delG and a previously reported c.1779A > T variants in EYA1. Two large heterozygous deletions involving EYA1 were detected in additional two families. Whole exome sequencing did not reveal a causative variant in the remaining four families. CONCLUSIONS: A variety of DNA changes including large deletions underlie BOR syndrome in different populations, which can be detected with comprehensive genetic testing.

Association between the APOE ε4 Allele and Late-Onset Alzheimer's Disease in an Ecuadorian Mestizo Population.

Alzheimer's disease (AD) is the most common neurodegenerative disease. It has two main pathological hallmarks: amyloid plaques and neurofibrillary tangles. The APOE ε4 allele has been recognized as the strongest genetic risk factor for late-onset Alzheimer's disease (LOAD) in several populations worldwide, yet the risk varies by region and ethnicity. The aims of this study were to describe APOE allele and genotype frequencies and examine the relationship between the APOE ε4 allele and LOAD risk in an Ecuadorian Mestizo population. We carried out a case-control study comprising 56 individuals clinically diagnosed with probable AD (≥65 years of age) and 58 unrelated healthy control subjects (≥65 years of age). Genotyping was performed using the real-time PCR method. Our data showed that allelic and genotypic frequencies follow the trends observed in most worldwide populations. We also found a high-risk association between APOE ε4 allele carriers and LOAD (OR = 7.286; 95% CI = 2.824-18.799; p < 0.001). Therefore, we concluded that APOE ε4 must be considered an important genetic risk factor for LOAD in the Ecuadorian Mestizo population. Additionally, we suggest that in mixed populations the effects of admixture and ethnic identity should be differentiated when evaluating genetic contributions to Alzheimer's disease risk.

Ataxia espinocerebelosa tipo 2: diagnóstico clínico y molecular de dos casos atendidos en el Hospital de Especialidades de las Fuerzas Armadas N°1 / Spinocerebellar ataxia type 2: clinical and molecular diagnosis of two cases treated at the Armed Forces N°1 Hospital

La ataxia espinocerebelosa tipo 2 (SCA2) es una enfermedad neurodegenerativa causada por la expansión del trinucleótido CAG en el exón 1 del gen Ataxina-2 (ATXN2), situado en la región cromosómica 12q23-24. Este es el primer reporte de diagnóstico molecular realizado en Ecuador para esta enfermedad. Presentación de los casos Dos pacientes ecuatorianos de género masculino de 39 y 46 años de edad fueron remitidos al Servicio de Genética Médica del Hospital de Especialidades de las Fuerzas Armadas Nº1 para identifcar el tipo de ataxia espinocerebelosa presente en cada caso. Para ambos pacientes, la evaluación clínica evidenció síntomas compatibles con una SCA2, el análisis genealógico mostró un patrón de herencia autosómico dominante y el diagnóstico molecular confrmó que la ataxia espinocerebelosa presente era de tipo 2. Conclusión El diagnóstico específco de las ataxias espinocerebelosas debe basarse principalmente en una correlación fenotípica-genotípica, la cual involucra evaluaciones clínicas, análisis genealógico y estudios genéticos moleculares para cada caso. La SCA2 constituye un tipo de enfermedad cuyo diagnóstico implica complejidades clínicas y genéticas, concluyendo que este proceso debe efectuarse con la inclusión del asesoramiento genético familiar, siendo el comienzo del manejo integral de esta enfermedad

La importancia de un diagnóstico clínico temprano en la distrofia muscular de Duchenne: mutaciones encontradas en siete pacientes ecuatorianos / The importance of early clinical diagnosis in Duchenne muscular dystrophy: mutations found in seven Ecuadorian patients

Duchenne muscular dystrophy (DMD) is a recessive X-linked genetic disease caused by mutations in the dystrophin gene. In Ecuador, the procedure to diagnose this disease is not standardized by the public health system. The aim of this study was to propose an algorithm for DMD diagnosis in order to establish a standard protocol, emphasize early diagnosis and identify pathological mutations in affected patients. Subjects and methods We reported seven Ecuadorian male patients with clinical signs of DMD. They were evaluated by pediatricians, neurologists and geneticists, who made a medical record considering age of onset, pedigree, symptoms, serum CK levels and EMG analysis results. The confrmatory diagnosis and the type of mutations were identifed by molecular genetic testing. Results The most common symptoms reported from patients were frequent falls, unstable gait, diminished muscular strength, calf pseudohypertrophy and diffculty climbing stairs. Moreover, two types of mutations in DMD gene were found, duplications and deletions. The effects of mutations in the reading frame were out-of frame for all patients, except for one, whose mutations showed an in-frame effect on the gene. Conclusions It is important to emphasize the timely diagnosis of DMD to reduce the appearance of new cases, as well as the emotional impact on families. When there is a suspicion of a neuromuscular condition in male children, we recommend following the proposed algorithm in order to offer an early and effcient DMD diagnosis, confrm the disease and to provide an appropriate genetic counseling to patients and their families

La Distrofa Muscular de Duchenne (DMD) es una enfermedad genética recesiva ligada al cromosoma X, causada por mutaciones en el gen de la distrofna. En Ecuador, el procedimiento para diagnosticar esta enfermedad no ha sido estandarizado por el Sistema de Salud Pública. El objetivo de este estudio fue proponer un algoritmo para el diagnóstico de DMD con el fn de establecer un protocolo estándar, enfatizar el diagnóstico temprano e identifcar las mutaciones patológicas en los pacientes afectados. Sujetos y métodos Se reportaron siete pacientes ecuatorianos masculinos con signos clínicos de DMD. Estos fueron evaluados por pediatras, neurólogos y genetistas, quienes elaboraron una historia clínica incluyendo datos de la edad de inicio, árbol genealógico, síntomas, resultados de los niveles de CK en suero y el análisis del EMG. El diagnóstico confrmatorio de DMD y el tipo de mutaciones fueron identifcados con pruebas genéticas moleculares. Resultados Los síntomas más comunes reportados en los pacientes fueron caídas frecuentes, inestabilidad en la marcha, disminución de la fuerza muscular, pseudo-hipertrofa de pantorrillas y difcultad para subir escaleras. Además, dos tipos de mutaciones fueron halladas en el gen DMD: duplicaciones y deleciones. Los efectos de las mutaciones en el marco de lectura del gen de la distrofna fueron out-frame para todos los pacientes, excepto en uno, cuyas mutaciones tuvieron un efecto in-frame sobre el gen. Conclusiones Enfatizar en el diagnóstico temprano de DMD es importante para reducir la aparición de nuevos casos, así como el impacto emocional en las familias. Cuando existe la sospecha de una enfermedad neuromuscular en niños, recomendamos seguir el algoritmo propuesto con el fn de ofrecer un diagnóstico oportuno y efciente, confrmar el diagnóstico de la enfermedad y proveer el asesoramiento genético apropiado a los pacientes y sus familiares

Manejo de la pareja esteril en Quito: un año de experiencia / Management of the sterile couple in Quito: 1-year experience

Entre Marzo de 1984 a Febrero de 1985, en el Instituto de Reproducción Humana de Quito, se estudiaron bajo un protocolo definido a 20 parejas estériles y 4 infértiles. En las estériles los factores etiológicos fueron anovulación crónica 7 casos (35%), tubo-peritoneal-uterino 7 casos (35%), masculino 5 (25%); imunológico 5 casos (25%), psicológico 2 casos (10%) y coital 1 caso (5%). El porcentaje de éxito en esta serie, entendido por embarazo con recién nacido vivo, fue del 30% (6 casos) en parejas estériles y del 75% (3 casos) en infértiles. En las 6 parejas estériles en las que se obtuvo éxito, dos fueron tratadas con clomifeno, con Psicoterapia 2 parejas, con Inseminación Artificial Heteróloga una paciente y con hormona específica para hipotiroidismo la restante. Las parejas infértiles representaron un esquema especial de estudio y tratamiento, de los 3 casos exitosos, uno fue con hormona tiroidea, otro con 17 alfa hidroxiprogesterona y el tercero con ceclaje cervical