Novel progressive acrodysostosis-like skeletal dysplasia, cerebellar atrophy, and ichthyosis.

Acrodysostosis refers to a rare heterogeneous group of bone dysplasias that share skeletal features, hormone resistance, and intellectual disability. Two genes have been associated with acrodysostosis with or without hormone resistance (PRKAR1A and PDE4D). Severe intellectual disability has been reported with acrodysostosis but brain malformations and ichthyosis have not been reported in these syndromes. Here we describe a female patient with acrodysostosis, intellectual disability, cerebellar hypoplasia, and lamellar ichthyosis. The patient has an evolving distinctive facial phenotype and childhood onset ataxia. X-rays showed generalized osteopenia, shortening of middle and distal phalanges, and abnormal distal epiphysis of the ulna and radius. Brain magnetic resonance imaging showed cerebellar atrophy without other brainstem abnormalities. Genetic workup included nondiagnostic chromosomal microarray and skeletal dysplasia molecular panels. These clinical findings are different from any recognized form of acrodysostosis syndrome. Whole exome sequencing did not identify rare or predicted pathogenic variants in genes associated with known acrodysostosis, lamellar ichthyosis, and other overlapping disorders. A broader search for rare alleles absent in healthy population databases and controls identified two heterozygous truncating alleles in FBNL7 and PPM1M genes, and one missense allele in the NPEPPS gene. Identification of additional patients is required to delineate the mechanism of this unique disorder.

Genética clínica comunitaria: exploración de patología genética en Boyacá, Colombia / Clinical community genetics: exploring genetic disorders in Boyacá, Colombia

RESUMEN Objetivo Explorar la presencia de patología genética sindrómica en el Departamento de Boyacá, mediante un acercamiento de medicina genética comunitaria. Materiales y Métodos Un grupo conformado por genetistas, neurólogo pediátrico y genetista bioquímico, llevó a cabo jornadas clínicas en las cuales se evaluaron pacientes con sospecha de enfermedad genética. Se obtuvieron datos demográficos, epidemiológicos y clínicos y se realizó el cálculo de frecuencias de los mismos. En los centros de referencia visitados se realizaron actividades de capacitación al personal médico. Resultados Se encontraron dos agrupamientos genéticos: MPSIII y Síndrome de Ellis Van Creveld, con incidencias mayores a lo reportado en la literatura, además una alta frecuencia de patologías de herencia autosómica recesiva, así como sospecha de síndromes de microdeleción-microduplicación. Conclusiones Se deben establecer mecanismos no convencionales de atención médica para facilitar el acceso a las comunidades a un diagnóstico y tratamiento adecuados en genética. Se espera que el apoyo brindado a los pacientes, familias y personal asistencial de los hospitales a través de las jornadas clínicas y la capacitación, permitan alcanzar este objetivo y a la vez sea un punto de inicio de procesos de prevención primaria y secundaria.(AU)

ABSTRACT Objectives To explore the incidence of syndromic genetic pathologies in Boyacá, Colombia, through a community genetics approach. Materials and Methods A group made up by different medical specialists (geneticists, a pediatric neurologist, and a biochemical geneticist) developed clinical campaigns, in which patients with clinical suspicion of genetic diseases were involved. Demographic, epidemiological and clinical data were collected, and frequency calculations were made based on the collected data. Several training workshops for health personnel were done in each center visited. Results Two genetic clusters were found: mucopolysaccharidosis type III, and Ellis-Van Creveld Syndrome, both of them with higher incidences than those found in the literature. Also, a high frequency of autosomal recessive diseases was found, as well as microdeletion/microduplication syndromes. Conclusions Conventional mechanisms of medical attention must be established, in order to facilitate the access to an appropriate diagnosis and treatment. This work intended to provide support to patients, families and health care services personnel through the workshops and clinical campaigns, and to become a starting point to develop primary and secondary prevention processes.(AU)

[Clinical community genetics: exploring genetic disorders in Boyacá, Colombia]. / Genética clínica comunitaria: exploración de patología genética en Boyacá, Colombia.

OBJECTIVES: To explore the incidence of syndromic genetic pathologies in Boyacá, Colombia, through a community genetics approach. MATERIALS AND METHODS: A group made up by different medical specialists (geneticists, a pediatric neurologist, and a biochemical geneticist) developed clinical campaigns, in which patients with clinical suspicion of genetic diseases were involved. Demographic, epidemiological and clinical data were collected, and frequency calculations were made based on the collected data. Several training workshops for health personnel were done in each center visited. RESULTS: Two genetic clusters were found: mucopolysaccharidosis type III, and Ellis-Van Creveld Syndrome, both of them with higher incidences than those found in the literature. Also, a high frequency of autosomal recessive diseases was found, as well as microdeletion/microduplication syndromes. CONCLUSIONS: Conventional mechanisms of medical attention must be established, in order to facilitate the access to an appropriate diagnosis and treatment. This work intended to provide support to patients, families and health care services personnel through the workshops and clinical campaigns, and to become a starting point to develop primary and secondary prevention processes.

OBJETIVO: Explorar la presencia de patología genética sindrómica en el Departamento de Boyacá, mediante un acercamiento de medicina genética comunitaria. MATERIALES Y MÉTODOS: Un grupo conformado por genetistas, neurólogo pediátrico y genetista bioquímico, llevó a cabo jornadas clínicas en las cuales se evaluaron pacientes con sospecha de enfermedad genética. Se obtuvieron datos demográficos, epidemiológicos y clínicos y se realizó el cálculo de frecuencias de los mismos. En los centros de referencia visitados se realizaron actividades de capacitación al personal médico. RESULTADOS: Se encontraron dos agrupamientos genéticos: MPSIII y Síndrome de Ellis Van Creveld, con incidencias mayores a lo reportado en la literatura, además una alta frecuencia de patologías de herencia autosómica recesiva, así como sospecha de síndromes de microdeleción-microduplicación. CONCLUSIONES: Se deben establecer mecanismos no convencionales de atención médica para facilitar el acceso a las comunidades a un diagnóstico y tratamiento adecuados en genética. Se espera que el apoyo brindado a los pacientes, familias y personal asistencial de los hospitales a través de las jornadas clínicas y la capacitación, permitan alcanzar este objetivo y a la vez sea un punto de inicio de procesos de prevención primaria y secundaria.

Charcot Marie Tooth disease (CMT4A) due to GDAP1 mutation: report of a colombian family / Enfermedad de Charcot Marie Tooth (CMT4A) por mutacion en el gen GDAP1: reporte de una familia colombiana

Background: Mutations of GDAP1 gene cause autosomal dominant and autosomal recessive Charcot-Marie-Tooth disease and more than 40 different mutations have been reported. The recessive Q163X mutation has been described in patients of Spanish ancestry, and a founder mutation in South American patients, originating in Spain has been demonstrated. Objective: We describe physical and histological features, and the molecular impact of mutation Q163X in a Colombian family. Methods: We report two female patients, daughters of consanguineous parents, with onset of symptoms within the first two years of life, developing severe functional impairment, without evidence of dysmorphic features, hoarseness or diaphragmatic paralysis. Electrophysiology tests showed a sensory and motor neuropathy with axonal pattern. Sequencing of GDAP1 gene was requested and the study identified a homozygous point mutation (c.487 C>T) in exon 4, resulting in a premature stop codon (p.Q163X). This result confirms the diagnosis of Charcot-Marie-Tooth disease, type 4A. Results: The patients were referred to Physical Medicine and Rehabilitation service, in order to be evaluated for ambulation assistance. They have been followed by Pulmonology service, for pulmonary function assessment and diaphragmatic paralysis evaluation. Genetic counseling was offered. The study of the genealogy of the patient, phenotypic features, and electrophysiological findings must be included as valuable tools in the clinical approach of the patient with Charcot-Marie-Tooth disease, in order to define a causative mutation. In patients of South American origin, the presence of GDAP1 gene mutations should be considered, especially the Q163X mutation, as the cause of CMT4A disease.

Antecedentes: Las mutaciones del gen GDAP1 son causantes de la enfermedad de Charcot Marie Tooth tanto autosómica dominante como recesiva, y se han reportado más de 40 mutaciones distintas. La mutación recesiva Q163X ha sido descrita en pacientes de ascendencia española y se ha demostrado una mutación fundadora originaria de España en pacientes de origen suramericano. Describimos las características físicas e histológicas y el impacto molecular de la mutación Q163X en una familia colombiana. Objetivo: Se describe el impacto de la mutación Q163X en las características físicas, histológicas y moleculares en una familia colombiana. Métodos: Se describe dos pacientes de sexo femenino, hijas de padres consanguíneos, quienes presentaron inicio de síntomas en los dos primeros años de vida, mostrando deterioro funcional severo, sin evidencia de dismorfía, disfonía o parálisis diafragmática. Los estudios de electrofisiología mostraron una neuropatía sensitiva y motora con patrón axonal. Se solicitó la secuenciación del gen GDAP1, y el estudio identificó una mutación homocigota puntual (c. 487 C>T) en el exón 4, causando un codón de parada prematuro (p. Q163X). Este resultado confirma el diagnóstico de Enfermedad de Charcot Marie Tooth, tipo 4A (recesiva, tipo axonal). Resultados: Las pacientes fueron remitidas al servicio de Fisiatría para evaluación de métodos de asistencia para deambulación. Ellas reciben seguimiento por el servicio de Neumología, quienes vigilan la función pulmonar y el desarrollo de parálisis diafragmática. Se brindó asesoramiento genético. La genealogía del paciente, las características fenotípicas y los hallazgos en los estudios electrofisiológicos son herramientas valiosas en el enfoque clínico del paciente con CMT, de forma que se pueda plantear una posible mutación causal. Se debe considerar la presencia de mutaciones en el gen GDAP1 en pacientes de origen suramericano, en especial la mutación Q163X, como causa de CMT4A.

Charcot Marie Tooth disease (CMT4A) due to GDAP1 mutation: report of a Colombian family.

BACKGROUND: Mutations of GDAP1 gene cause autosomal dominant and autosomal recessive Charcot-Marie-Tooth disease and more than 40 different mutations have been reported. The recessive Q163X mutation has been described in patients of Spanish ancestry, and a founder mutation in South American patients, originating in Spain has been demonstrated. OBJECTIVE: We describe physical and histological features, and the molecular impact of mutation Q163X in a Colombian family. METHODS: We report two female patients, daughters of consanguineous parents, with onset of symptoms within the first two years of life, developing severe functional impairment, without evidence of dysmorphic features, hoarseness or diaphragmatic paralysis. Electrophysiology tests showed a sensory and motor neuropathy with axonal pattern. Sequencing of GDAP1 gene was requested and the study identified a homozygous point mutation (c.487 C>T) in exon 4, resulting in a premature stop codon (p.Q163X). This result confirms the diagnosis of Charcot-Marie-Tooth disease, type 4A. RESULTS: The patients were referred to Physical Medicine and Rehabilitation service, in order to be evaluated for ambulation assistance. They have been followed by Pulmonology service, for pulmonary function assessment and diaphragmatic paralysis evaluation. Genetic counseling was offered. The study of the genealogy of the patient, phenotypic features, and electrophysiological findings must be included as valuable tools in the clinical approach of the patient with Charcot-Marie-Tooth disease, in order to define a causative mutation. In patients of South American origin, the presence of GDAP1 gene mutations should be considered, especially the Q163X mutation, as the cause of CMT4A disease.

ANTECEDENTES: Las mutaciones del gen GDAP1 son causantes de la enfermedad de Charcot Marie Tooth tanto autosómica dominante como recesiva, y se han reportado más de 40 mutaciones distintas. La mutación recesiva Q163X ha sido descrita en pacientes de ascendencia española y se ha demostrado una mutación fundadora originaria de España en pacientes de origen suramericano. Describimos las características físicas e histológicas y el impacto molecular de la mutación Q163X en una familia colombiana. OBJETIVO: Se describe el impacto de la mutación Q163X en las características físicas, histológicas y moleculares en una familia colombiana. MÉTODOS: Se describe dos pacientes de sexo femenino, hijas de padres consanguíneos, quienes presentaron inicio de síntomas en los dos primeros años de vida, mostrando deterioro funcional severo, sin evidencia de dismorfía, disfonía o parálisis diafragmática. Los estudios de electrofisiología mostraron una neuropatía sensitiva y motora con patrón axonal. Se solicitó la secuenciación del gen GDAP1, y el estudio identificó una mutación homocigota puntual (c. 487 C>T) en el exón 4, causando un codón de parada prematuro (p. Q163X). Este resultado confirma el diagnóstico de Enfermedad de Charcot Marie Tooth, tipo 4A (recesiva, tipo axonal). RESULTADOS: Las pacientes fueron remitidas al servicio de Fisiatría para evaluación de métodos de asistencia para deambulación. Ellas reciben seguimiento por el servicio de Neumología, quienes vigilan la función pulmonar y el desarrollo de parálisis diafragmática. Se brindó asesoramiento genético. La genealogía del paciente, las características fenotípicas y los hallazgos en los estudios electrofisiológicos son herramientas valiosas en el enfoque clínico del paciente con CMT, de forma que se pueda plantear una posible mutación causal. Se debe considerar la presencia de mutaciones en el gen GDAP1 en pacientes de origen suramericano, en especial la mutación Q163X, como causa de CMT4A.

Three-layer sandwich gel electrophoresis: a method of salt removal and protein concentration in proteome analysis.

Sample preparation plays a critical role in successful proteomic applications. Features of electrospray mass spectrometry impose limits on the types of buffers, detergents and other reagents that can be used in sample preparation. Unfortunately, many of these mass spectrometry incompatible reagents significantly enhance protein recoveries from complex matrices. This problem prompted our search for a better cleanup protocol. Our data suggest that the Three-layer Sandwich Gel Electrophoresis (TSGE) protocol can solve this problem and provide near quantitative recovery of extremely low concentration proteins from harsh solutions, a feature not available from other cleanup protocols. The hallmark of the TSGE protocol is the combination of the properties of agarose gels (that serve as the matrix to immobilize the proteins of interest) with low- and high-percentage polyacrylamide gels (that serve as the concentration and sealing layers, respectively). By electrophoretically driving the proteins of interest from the agarose matrix into the concentration layer, the TSGE protocol simultaneously concentrates the sample in the concentration layer and provides an environment amenable to downstream buffer exchange and proteolytic digestion. In combination with 2D-LC-MS/MS, the TSGE protocol was evaluated in the analysis of a whole cell extract from the protozoan parasite Toxoplasma gondii. Comparison of our experimental proteomic results with in silico predictions from gene data indicated that TSGE did not bias the protein identification.

Elimination of affinity reagent interference for the mass spectrometric detection of low-abundance proteins following immunoprecipitation.

The presence of affinity reagents such as immunoglobulin in preparations for sensitive mass spectrometry analyses can preclude the identification of low-abundance proteins of interest. We report a method whereby antisera are purified and biotinylated prior to use in immunoprecipitation that allows for its efficient removal from proteomic samples via streptavidin capture. This method can similarly be extended to other affinity reagents such as recombinant fusion proteins for enhanced identification of interacting proteins.

The Toxoplasma gondii parasitophorous vacuole membrane: transactions across the border.

The obligate intracellular protozoan Toxoplasma gondii establishes its replication permissive niche within the infected host cell. This niche, the parasitophorous vacuole (PV), is delimited from the host cell cytoplasm by the PV membrane (PVM). In this chapter we highlight the roles of the PVM in the remodeling of host cell architecture, nutrient acquisition, the manipulation of signaling, and touch upon the potential roles in the parasite developmental cycle. We further present the PVM as a unique and dynamic "organelle" found only within the infected cell where it is established outside the parent organism. Despite its importance little is known about the biology of the PVM. There has, however, been a recent renewal of interest in the PVM, the study of which has become more tractable with the application of both classical approaches as well as genomic and proteomic analyses. In this review we discuss the diverse activities associated with the PVM and present pressing questions that remain to be elucidated regarding this enigmatic organelle.