Aberrant spliceosome activity via elevated intron retention and upregulation and phosphorylation of SF3B1 in chronic lymphocytic leukemia.

Splicing factor 3b subunit 1 (SF3B1) is the largest subunit and core component of the spliceosome. Inhibition of SF3B1 was associated with an increase in broad intron retention (IR) on most transcripts, suggesting that IR can be used as a marker of spliceosome inhibition in chronic lymphocytic leukemia (CLL) cells. Furthermore, we separately analyzed exonic and intronic mapped reads on annotated RNA-sequencing transcripts obtained from B cells (n = 98 CLL patients) and healthy volunteers (n = 9). We measured intron/exon ratio to use that as a surrogate for alternative RNA splicing (ARS) and found that 66% of CLL-B cell transcripts had significant IR elevation compared with normal B cells (NBCs) and that correlated with mRNA downregulation and low expression levels. Transcripts with the highest IR levels belonged to biological pathways associated with gene expression and RNA splicing. A >2-fold increase of active pSF3B1 was observed in CLL-B cells compared with NBCs. Additionally, when the CLL-B cells were treated with macrolides (pladienolide-B), a significant decrease in pSF3B1, but not total SF3B1 protein, was observed. These findings suggest that IR/ARS is increased in CLL, which is associated with SF3B1 phosphorylation and susceptibility to SF3B1 inhibitors. These data provide additional support to the relevance of ARS in carcinogenesis and evidence of pSF3B1 participation in this process.

Predictors and Management of Relapse to Axicabtagene Ciloleucel in Patients with Aggressive B-cell Lymphoma.

OBJECTIVE/BACKGROUND: Despite the success of chimeric antigen receptor (CAR) T-cell therapy in patients with aggressive non-Hodgkin lymphoma (aNHL), some patients still fail treatment, and their prognosis is dismal. METHODS: We performed a retrospective study of aNHL patients treated with axicabtagene ciloleucel (axi-cel) at two Mayo Clinic centers between 2018 and 2020. We evaluated predictive factors, toxicities, and responses to salvage regimens after CAR T-cell therapy. RESULTS: Thirty-four patients received axi-cel with a median length of hospitalization of 14 days. Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome of any grade occurred in 91% and 41% of patients, respectively. Furthermore, 71% of patients responded to therapy, with 53% achieving a complete response (CR). The CRS grade and absolute lymphocyte count at leukapheresis (ALCLeuk) correlated with CR and overall survival (OS), respectively. After a median follow-up of 6.8 months (interquartile range [IQR] 4.6-14.9), 15 patients (44%) showed progressive disease (PD). Most patients (60%) progressed during the first 3 months and had persistent CD19 tumor expression. Elevated C-reactive protein at baseline increased the risk of PD, whereas elevated ferritin increased PD and mortality risk. Twelve patients received salvage therapy, but only three responded. Median OS of relapsed/refractory patients to axi-cel was 3 months (IQR 1.3-5.1). CONCLUSION: The grade of CRS and ALCLeuk correlated with better outcomes to axi-cel therapy. In addition, elevated inflammatory markers at baseline were associated with PD and shorter survival. Relapses after treatment frequently occur within months after axi-cel infusion; they confer a poor prognosis and create an urgent need for novel and effective treatment options in this patient population.

Mosaicism in Fragile X syndrome: A family case series.

Fragile X syndrome (FXS) has a classic phenotype, however its expression can be variable among full mutation males. This is secondary to variable methylation mosaicisms and the number of CGG triplet repeats in the non-coding region of the Fragile X Mental Retardation 1 (FMR1) gene, producing a variable expression of the Fragile X Mental Retardation Protein (FMRP). Here we report a family with several individuals affected by FXS: a boy with a hypermethylated FMR1 mutation and a classic phenotype; a man with an FMR1 gene mosaicism in the range of premutation (PM) and full mutation (FM), who has a mild phenotype due to which FXS was initially disregarded; and the cases of four women with a FM and mosaicism. This report highlights the importance of DNA molecular testing for the diagnosis of FXS in patients with developmental delay, intellectual disability and/or autism due to the variable phenotype that occurs in individuals with FMR1 mosaicisms.

Genetic cluster of fragile X syndrome in a Colombian district.

BACKGROUND: Fragile X syndrome (FXS) is the most common cause of inherited intellectual disabilities and autism. The reported prevalence of the full mutation (FM) gene FMR1 in the general population is 0.2-0.4 per 1000 males and 0.125-0.4 per 1000 females. Population screening for FMR1 expanded alleles has been performed in newborns and in an adult population. However, it has never been carried out in an entire town. Ricaurte is a Colombian district with 1186 habitants, with a high prevalence of FXS, which was first described by cytogenetic techniques in 1999. METHODS: Using a PCR-based approach, screening for FXS was performed on blood spot samples obtained from 926 (502 males and 424 females) inhabitants from Ricaurte, accounting for 78% of total population. RESULTS: A high prevalence of carriers of the expanded allele was observed in all FXS mutation categories. Using the Bayesian methods the carrier frequency of FM was 48.2 (95% Credibility Region CR: 36.3-61.5) per 1000 males and 20.5 (95% CR:13.5-28.6) per 1000 females; the frequency of premutation carrier was 14.1 (95% RC: 8.0-21.7) per 1000 males (95% RC: 8.0-21.7 per 1000 males) and 35.9 (95% RC: 26.5-46.2) per 1000 for females (95% RC: 26.5-46.2 per 1000 females), and gray zone carrier was 13.4 (95% RC: 7.4-20.7) per 1000 males (95% RC: 7.4-20.7 per 1000 males) and 42.2 (95% RC: 32.2-53.8) per 1000 for females (95% RC: 32.2-53.8 per 1000 females). Differences in carrier frequencies were observed for premutation and FM alleles between natives and non-natives. CONCLUSIONS: This study shows that in Ricaurte the carrier frequencies of FMR1 expanded alleles (premutations and FMs) are higher than those reported in the literature, suggesting that Ricaurte constitutes a genetic cluster of FXS.

Síndrome de deleción 22q11: bases embriológicas y algoritmo diagnóstico / 22q11 deletion syndrome: embryology and diagnostic algorithm

Resumen El síndrome de deleción 22q11 consiste en una agrupación variable de características fenotípicas secundarias a la pérdida del material genético localizado en la banda 22q11.2. El espectro de deleción del 22q11 abarca varios síndromes, antes considerados independientes pero hoy relacionados con la misma etiología, con anomalías superpuestas incluyendo el síndrome de DiGeorge y el síndrome velocardiofacial, entre otros. Se trata de un síndrome pleiotrópico incluyendo: alteraciones en los sistemas cardiaco e inmunológico, dificultades en el aprendizaje y malformaciones del paladar entre las afecciones más comunes. Se hizo una revisión de: la base embriológica de las malformaciones congénitas cardiacas, la epidemiología, la genética, la fisiopatología y los aspectos clínicos en el manejo de esta enfermedad. Dado que esta enfermedad rara es potencialmente una causa importante pero ignorada de morbimortalidad en Colombia, se propone también una estrategia para su búsqueda activa y se discuten aspectos relacionados con su diagnóstico.

Abstract The 22q11 deletion syndrome is characterized by a variable group of phenotypic features secondary to the loss of genetic material located on the band 22q11.2. Its spectrum covers multiple syndromes, previously considered independent but nowadays related to the same etiology with overlapping anomalies, including DiGeorge and velocardiofacial syndromes. It presents alterations in the immune and cardiac systems, neurodevelopment and palatal defects amongst the most common problems. This article is a review of the embryologic basis for the congenital heart defects, epidemiology, genetics, pathophysiology and clinical aspects of this disease. This is a rare disease but is a potentially underdiagnosed cause of morbidity and mortality in Colombia, for which a strategy for its active search is also proposed and diagnostic aspects are discussed.

Surgimiento de los micro-RNA como biomarcadores potenciales en diversas enfermedades / Emergence of micro-RNAs as potential biomarkers in different diseases / Surgimento dos micro-RNA como bio-marcadores potenciais em diversas doenças

El objetivo de esta revisión es evidenciar el potencial de los micro-RNA (mi-RNA) como biomarcadores en diferentes enfermedades. Los mi-RNA son ácidos nucleicos de ≈ 22 nucleótidos que regulan la traducción de RNA mensajeros (mRNA) codificantes y producen una regulación postranscripcional de la expresión génica. La mayoría de ellos son altamente conservados y tienen una distribución tisular específica, de manera que juegan un papel importante como reguladores de la función celular y la fisiopatología de los diferentes órganos del cuerpo humano. Los mi-RNA surgen como candidatos para ser biomarcadores debido a que se han encontrado cambios en su expresión en diversas enfermedades (cáncer, daño hepático y cardiopatías), con alteración de sus niveles en plasma suero, orina y saliva. Sin embargo, aunque algunos presentan consistencia en su perfil de expresión, otros han sido reportados como posibles candidatos para más de una enfermedad, lo que limita su especificidad y su utilidad diagnóstica. Es pertinente hacer nuevos estudios que ahonden sobre su significado en procesos patológicos y sobre su papel como posibles biomarcadores.

The objective of this review is to evidence the potential of micro-RNAs (mi-RNAs) as possible diagnostic biomarkers in different diseases. Micro-RNAs are nucleic acids of 22 nucleotides that regulate the translation of coding messenger RNAs (mRNAs), and produce a post-transcriptional regulation of genetic expression. Most mi-RNAs are highly conserved and show a tissue-specific distribution; therefore, they play an important role in the regulation of cell function and the physiopathology of different organs. Micro-RNAs emerge as potential candidates for biomarkers due to the changes in their levels of expression in different situations (cancer, hepatic and cardiovascular diseases) and in fluids such as plasma, serum, urine and saliva. However, although some mi-RNAs have a consistent expression profile, others have been reported as possible biomarkers for more than one disease, thus limiting their specificity and usefulness as diagnostic tools. Further studies are important to define the significance of mi-RNAs in pathologic processes and their role as possible biomarkers.

O objetivo desta revisão é evidenciar o potencial dos micro-RNA (mi-RNA) como bio-marcadores em diferentes doenças. Os mi-RNA são ácidos nucleicos de ≈ 22 nucleótidos que regulam a tradução de RNA mensageiros (mRNA) codificantes e produzem uma regulação pós-transcripcional da expressão génica. A maioria desses são altamente conservados e tem uma distribuição tissular específica, de maneira que jogam um papel importante como reguladores da função celular e a fisiopatologia dos diferentes órgãos do corpo humano. Os mi-RNA surgem como candidatos para ser bio-marcadores devido a que se hão encontrado câmbios em sua expressão em diversas doenças (câncer, dano hepático e cardiopatias), com alteração de seus níveis em plasma, soro, urina e saliva. Embora, ainda alguns apresentam consistência em seu perfil de expressão, outros hão sido reportados como possíveis candidatos para mais de uma doença, o que limita sua especificidade e sua utilidade diagnóstica. É pertinente fazer novos estudos que abondem sobre seu significado em processos patológicos e sobre seu papel como possível bio-marcadores.

Síndrome de temblor y ataxia asociado a frágil X (FXTAS): revisión dela literatura / Fragile X associated tremor/ataxia syndrome: literature review

El síndrome de temblor y ataxia asociado al síndrome del cromosoma X frágil (FXTAS) es un desorden neurodegenerativoprogresivo (1), de inicio tardío, que ocurre entre los portadores de la premutación del gen FMR1(Fragile X Mental Retardation 1), el cual está estrechamente asociado con el síndrome del cromosoma X frágil(FXS). El FXTAS se caracteriza por déficits neurológicos que incluyen temblor de intención progresivo, ataxiacerebelosa, parkinsonismo, neuropatía periférica, déficits cognitivos y disfunción autonómica (2-4).El FXTAS surge como una importante opción diagnóstica en hombres con temblor, alteraciones en la marchay síntomas neurodegenerativos. En general existe subregistro de esta patología dado que es un síndrome recientementedescrito y falta conocimiento de los profesionales de salud al respecto, los cuales, debido a la similitudde su presentación clínica con otros desórdenes neurológicos, generalmente suelen confundir el diagnóstico (5).En Colombia no se ha documentado la prevalencia de SXF o de FXTAS. Sin embargo, se ha descrito un corregimientoen el Valle del Cauca que tiene una prevalencia de más de cien veces lo reportado en la literatura deSFX, lo que nos sugiere que en Colombia existe subregistro del SFX y de FXTAS.Esta revisión tiene por objeto difundir los avances del conocimiento de las manifestaciones clínicas, la neurofisiopatologíay las posibilidades de tratamiento de los pacientes con FXTAS, y así aumentar diagnóstico yaportar a mejorar la calidad de vida de los afectados y de sus familias.

Fragile X Syndrome / Síndrome de X Frágil

Fragile X Syndrome (FXS) is a genetic disease due to a CGG trinucleotide expansion, named full mutation (greater than 200 CGG repeats), in the FMR1 gene locus Xq27.3; which leads to an hypermethylated region in the gene promoter therefore silencing it and lowering the expression levels of FMRP, a protein involved in synaptic plasticity and maturation. Individuals with FXS present with intellectual disability, autism, hyperactivity, long face, large or prominent ears and macroorchidism at puberty and thereafter. Most of the young children with FXS will present with language delay, sensory hyper arousal and anxiety. Girls are less affected than boys, only 25% have intellectual disability. Given the genomic features of the syndrome, there are patients with a number of triplet repeats between 55 and 200, known as premutation (PM) carriers. Most carriers have a normal IQ but some have developmental problems. The diagnosis of FXS has evolved from karyotype with special culture medium, to molecular techniques that are more sensitive and specific including PCR and Southern Blot. During the last decade, the advances in the knowledge of FXS, has led to the development of investigations on pharmaceutical management or targeted treatments for FXS. Minocycline and sertraline have shown efficacy in children.

El Síndrome de X Frágil (SXF), es una enfermedad genética debida a una expansión del trinucleótido CGG, nombrada mutación completa (más de 200 repeticiones de CGG) en el gen FMR1, locus Xq27.3; la cual lleva a una hipermetilación de la región promotora del gen, silenciándolo y disminuyendo los niveles de expresión de la proteína FMRP relacionada con la plasticidad y maduración neuronal. Los individuos con SXF presentan retardo mental, autismo, hiperactividad, cara alargada, orejas grandes o prominentes y macroorquidismo desde la pubertad. La mayoría de niños con SXF presentan retraso en el lenguaje, hiperactivación sensorial y ansiedad. Las niñas se afectan menos que los varones, solo el 25% presenta retardo mental. Dadas las características genómicas del síndrome, existen pacientes con un número de repetición de la tripleta entre 55 y 200 que se denominan portadores de la premutación. La mayoría de los portadores tienen un coeficiente intelectual normal, pero presentan problemas en el desarrollo. El diagnóstico en SXF ha evolucionado del cariotipo con medio especial de cultivo, a pruebas moleculares más sensibles y específicas incluyendo PCR y Southern blot. Durante la última década, los avances en el conocimiento sobre el SXF han permitido el desarrollo de investigaciones sobre el manejo farmacológico o tratamientos específicos para el SXF. La minociclina y la sertralina han demostrado eficacia en niños.

Fragile X syndrome.

Fragile X Syndrome (FXS) is a genetic disease due to a CGG trinucleotide expansion, named full mutation (greater than 200 CGG repeats), in the fragile X mental retardation 1 gene locus Xq27.3; which leads to an hypermethylated region in the gene promoter therefore silencing it and lowering the expression levels of the fragile X mental retardation 1, a protein involved in synaptic plasticity and maturation. Individuals with FXS present with intellectual disability, autism, hyperactivity, long face, large or prominent ears and macroorchidism at puberty and thereafter. Most of the young children with FXS will present with language delay, sensory hyper arousal and anxiety. Girls are less affected than boys, only 25% have intellectual disability. Given the genomic features of the syndrome, there are patients with a number of triplet repeats between 55 and 200, known as premutation carriers. Most carriers have a normal IQ but some have developmental problems. The diagnosis of FXS has evolved from karyotype with special culture medium, to molecular techniques that are more sensitive and specific including PCR and Southern Blot. During the last decade, the advances in the knowledge of FXS, has led to the development of investigations on pharmaceutical management or targeted treatments for FXS. Minocycline and sertraline have shown efficacy in children.

El Síndrome de X Frágil (SXF), es una enfermedad genética debida a una expansión del trinucleótido CGG, nombrada mutación completa (más de 200 repeticiones de CGG) en el locus Xq27.3 del gen X fragil de retardo mental; la cual lleva a una hipermetilación de la región promotora del gen, silenciándolo y disminuyendo los niveles de expresión de la proteína X frágil de retardo mental 1, relacionada con la plasticidad y maduración neuronal. Los individuos con SXF presentan retardo mental, autismo, hiperactividad, cara alargada, orejas grandes o prominentes y macroorquidismo desde la pubertad. La mayoría de niños con SXF presentan retraso en el lenguaje, hiperactivación sensorial y ansiedad. Las niñas se afectan menos que los varones, solo el 25% presenta retardo mental. Dadas las características genómicas del síndrome, existen pacientes con un número de repetición de la tripleta entre 55 y 200 que se denominan portadores de la premutación. La mayoría de los portadores tienen un coeficiente intelectual normal, pero presentan problemas en el desarrollo. El diagnóstico en SXF ha evolucionado del cariotipo con medio especial de cultivo, a pruebas moleculares más sensibles y específicas incluyendo PCR y Southern blot. Durante la última década, los avances en el conocimiento sobre el SXF han permitido el desarrollo de investigaciones sobre el manejo farmacológico o tratamientos específicos para el SXF. La minociclina y la sertralina han demostrado eficacia en niños.