RESUMO
Telangiectasia-ectodermal dysplasia-brachydactyly-cardiac anomaly (TEBC) syndrome is a rare autosomal dominant condition, recently linked to the protein kinase D1 (PRKD1) gene. The phenotype of TEBC remains incomplete at this point. Our aim is to improve the characterization of the clinical and molecular aspects of the TEBC syndrome. We report on the 8th patient carrying a heterozygous de novo variation of PRKD1 c.2134G > A, p. (Val712Met) identified by trio exome sequencing. The proband presents with partial atrioventricular septal defect, brachydactyly, ectodermal dysplasia, telangiectasia that developed in childhood, intellectual disability with microcephaly, multicystic renal dysplasia and moderate hormonal resistance. In view of this 8th description and review of the literature, it appears that neurodevelopmental disorders and microcephaly are frequently associated with PRKD1 missense variants, adding to the four main clinical signs described initially in the TEBC syndrome. Further descriptions are required to confirm the observed endocrine and kidney abnormalities. This should contribute to a more comprehensive understanding of the phenotypic spectrum and may help establish genotype-phenotype correlations. In the context of genotype-first strategy, accurate patient descriptions are fundamental. Characterization of specific syndromic associations is essential for variant interpretation support and patient follow-up, even in very rare diseases, such as the TEBC syndrome.
Assuntos
Displasia Ectodérmica , Cardiopatias Congênitas , Humanos , Displasia Ectodérmica/genética , Displasia Ectodérmica/patologia , Cardiopatias Congênitas/genética , Cardiopatias Congênitas/patologia , Fenótipo , Braquidactilia/genética , Braquidactilia/patologia , Masculino , Telangiectasia/genética , Telangiectasia/patologia , Feminino , Mutação de Sentido Incorreto , Síndrome , Microcefalia/genética , Microcefalia/patologia , Criança , Proteína Quinase CRESUMO
Lissencephaly (LIS) is a malformation of cortical development due to deficient neuronal migration and abnormal formation of cerebral convolutions or gyri. Thirty-one LIS-associated genes have been previously described. Recently, biallelic pathogenic variants in CRADD and PIDD1, have associated with LIS impacting the previously established role of the PIDDosome in activating caspase-2. In this report, we describe biallelic truncating variants in CASP2, another subunit of PIDDosome complex. Seven patients from five independent families presenting with a neurodevelopmental phenotype were identified through GeneMatcher-facilitated international collaborations. Exome sequencing analysis was carried out and revealed two distinct novel homozygous (NM_032982.4:c.1156delT (p.Tyr386ThrfsTer25), and c.1174 C > T (p.Gln392Ter)) and compound heterozygous variants (c.[130 C > T];[876 + 1 G > T] p.[Arg44Ter];[?]) in CASP2 segregating within the families in a manner compatible with an autosomal recessive pattern. RNA studies of the c.876 + 1 G > T variant indicated usage of two cryptic splice donor sites, each introducing a premature stop codon. All patients from whom brain MRIs were available had a typical fronto-temporal LIS and pachygyria, remarkably resembling the CRADD and PIDD1-related neuroimaging findings. Other findings included developmental delay, attention deficit hyperactivity disorder, hypotonia, seizure, poor social skills, and autistic traits. In summary, we present patients with CASP2-related ID, anterior-predominant LIS, and pachygyria similar to previously reported patients with CRADD and PIDD1-related disorders, expanding the genetic spectrum of LIS and lending support that each component of the PIDDosome complex is critical for normal development of the human cerebral cortex and brain function.
Assuntos
Lisencefalia , Transtornos do Neurodesenvolvimento , Humanos , Caspase 2/genética , Lisencefalia/diagnóstico por imagem , Lisencefalia/genética , Alelos , Transtornos do Neurodesenvolvimento/genética , Códon sem Sentido , Fenótipo , Cisteína Endopeptidases/genéticaRESUMO
RESEARCH QUESTION: Do patients presenting with flagella ultrastructural defects as assessed by electron microscopy, and defined within three phenotypes (dysplasia of the fibrous sheath [DFS], primary flagellar dyskinesia [PFD] and non-specific flagellar abnormalities [NSFA]), have decreased chances of success in intracytoplasmic sperm injection (ICSI) or adverse obstetric and neonatal outcomes? DESIGN: Retrospective analysis of 189 ICSI cycles from 80 men with spermatozoa flagellum ultrastructural defects (DFS [nâ¯=â¯16]; PFD [nâ¯=â¯14]; NSFA [nâ¯=â¯50] compared with a control group (nâ¯=â¯97). Cycles were cumulatively analysed. All fresh and frozen embryo transfers resulting from each ICSI attempt were included. The effect of transmission electron microscopy (TEM) phenotype on the main ICSI outcomes was assessed by a multivariate logistic regression combined with a generalized linear mixed model to account for the non-independence of the observations. RESULTS: No predictive value of TEM phenotype was found on the main outcomes of ICSI, namely fertilization rates, pregnancy and delivery rates, and cumulative pregnancy and delivery rates. Cumulative pregnancy rates ranged from 29.0-43.3% in the different TEM phenotype subgroups compared with 36.8% in the control group. Cumulative live birth rates ranged from 24.6-36.7% compared with 31.4% in the control group. No increase was found in miscarriages, preterm births, low birth weights or birth abnormalities. CONCLUSIONS: Data on the cumulative chances of success in ICSI of patients with ultrastructural flagellar defects, a rare cause of male infertility often associated with an underlying genetic cause, are reassuring, as are obstetrical and neonatal outcomes in this population.
Assuntos
Astenozoospermia , Infertilidade Masculina , Gravidez , Recém-Nascido , Feminino , Humanos , Masculino , Injeções de Esperma Intracitoplásmicas/efeitos adversos , Estudos Retrospectivos , Sêmen , Infertilidade Masculina/terapia , Infertilidade Masculina/etiologia , Taxa de Gravidez , Microscopia Eletrônica de Transmissão , Fertilização in vitroRESUMO
BACKGROUND AND OBJECTIVES: KCNH5 encodes the voltage-gated potassium channel EAG2/Kv10.2. We aimed to delineate the neurodevelopmental and epilepsy phenotypic spectrum associated with de novo KCNH5 variants. METHODS: We screened 893 individuals with developmental and epileptic encephalopathies for KCNH5 variants using targeted or exome sequencing. Additional individuals with KCNH5 variants were identified through an international collaboration. Clinical history, EEG, and imaging data were analyzed; seizure types and epilepsy syndromes were classified. We included 3 previously published individuals including additional phenotypic details. RESULTS: We report a cohort of 17 patients, including 9 with a recurrent de novo missense variant p.Arg327His, 4 with a recurrent missense variant p.Arg333His, and 4 additional novel missense variants. All variants were located in or near the functionally critical voltage-sensing or pore domains, absent in the general population, and classified as pathogenic or likely pathogenic using the American College of Medical Genetics and Genomics criteria. All individuals presented with epilepsy with a median seizure onset at 6 months. They had a wide range of seizure types, including focal and generalized seizures. Cognitive outcomes ranged from normal intellect to profound impairment. Individuals with the recurrent p.Arg333His variant had a self-limited drug-responsive focal or generalized epilepsy and normal intellect, whereas the recurrent p.Arg327His variant was associated with infantile-onset DEE. Two individuals with variants in the pore domain were more severely affected, with a neonatal-onset movement disorder, early-infantile DEE, profound disability, and childhood death. DISCUSSION: We describe a cohort of 17 individuals with pathogenic or likely pathogenic missense variants in the voltage-sensing and pore domains of Kv10.2, including 14 previously unreported individuals. We present evidence for a putative emerging genotype-phenotype correlation with a spectrum of epilepsy and cognitive outcomes. Overall, we expand the role of EAG proteins in human disease and establish KCNH5 as implicated in a spectrum of neurodevelopmental disorders and epilepsy.
Assuntos
Epilepsia Generalizada , Epilepsia , Canais de Potássio Éter-A-Go-Go , Criança , Humanos , Recém-Nascido , Epilepsia/genética , Epilepsia Generalizada/genética , Mutação , Fenótipo , Convulsões/genética , Canais de Potássio Éter-A-Go-Go/genéticaRESUMO
Congenital anomalies of the kidney and urinary tract (CAKUT) represent the most common cause of chronic kidney failure in children. Despite growing knowledge of the genetic causes of CAKUT, the majority of cases remain etiologically unsolved. Genetic alterations in roundabout guidance receptor 1 (ROBO1) have been associated with neuronal and cardiac developmental defects in living individuals. Although Slit-Robo signaling is pivotal for kidney development, diagnostic ROBO1 variants have not been reported in viable CAKUT to date. By next-generation-sequencing methods, we identified six unrelated individuals and two non-viable fetuses with biallelic truncating or combined missense and truncating variants in ROBO1. Kidney and genitourinary manifestation included unilateral or bilateral kidney agenesis, vesicoureteral junction obstruction, vesicoureteral reflux, posterior urethral valve, genital malformation, and increased kidney echogenicity. Further clinical characteristics were remarkably heterogeneous, including neurodevelopmental defects, intellectual impairment, cerebral malformations, eye anomalies, and cardiac defects. By in silico analysis, we determined the functional significance of identified missense variants and observed absence of kidney ROBO1 expression in both human and murine mutant tissues. While its expression in multiple tissues may explain heterogeneous organ involvement, variability of the kidney disease suggests gene dosage effects due to a combination of null alleles with mild hypomorphic alleles. Thus, comprehensive genetic analysis in CAKUT should include ROBO1 as a new cause of recessively inherited disease. Hence, in patients with already established ROBO1-associated cardiac or neuronal disorders, screening for kidney involvement is indicated.
Assuntos
Proteínas do Tecido Nervoso/genética , Receptores Imunológicos/genética , Sistema Urinário , Anormalidades Urogenitais , Refluxo Vesicoureteral , Animais , Criança , Feminino , Humanos , Rim/patologia , Masculino , Camundongos , Sistema Urinário/patologia , Anormalidades Urogenitais/diagnóstico , Anormalidades Urogenitais/genética , Refluxo Vesicoureteral/diagnóstico , Proteínas RoundaboutRESUMO
Emphysema is a chronic respiratory disorder characterized by destruction of alveoli, usually due to cigarette smoking or exposure to noxious particles or gases. Dysfunction of proteins that are involved in lung development and maintenance, such as alpha-1 antitrypsin, also contributes to emphysema. Filamin A (FLNA) is an actin-binding protein involved in cytoskeleton reorganization. Mutations in the FLNA gene classically lead to abnormal neuronal migration and connective and vascular tissue anomalies. Pulmonary manifestations consist of a wide range of pulmonary disorders that occur during infancy. We report the first familial case of emphysema in non- and very low-smoking adults who carry a loss-of-function mutation of the FLNA gene. The identification of this new risk factor for emphysema encourages (1) screening, prevention and monitoring of pulmonary disorders in patients with FLNA mutation and (2) screening for FLNA mutation in patients with early-onset emphysema that is associated with low-smoking or vascular or connective tissue anomalies.
Assuntos
Filaminas/genética , Pulmão/diagnóstico por imagem , Enfisema Pulmonar , Adulto , Idoso , Feminino , Predisposição Genética para Doença , Testes Genéticos/métodos , Humanos , Mutação com Perda de Função , Anamnese , não Fumantes , Linhagem , Heterotopia Nodular Periventricular/diagnóstico , Heterotopia Nodular Periventricular/genética , Enfisema Pulmonar/diagnóstico , Enfisema Pulmonar/genética , Enfisema Pulmonar/fisiopatologia , Tomografia Computadorizada por Raios X/métodosRESUMO
PURPOSE: Somatic variants in tumor necrosis factor receptor-associated factor 7 (TRAF7) cause meningioma, while germline variants have recently been identified in seven patients with developmental delay and cardiac, facial, and digital anomalies. We aimed to define the clinical and mutational spectrum associated with TRAF7 germline variants in a large series of patients, and to determine the molecular effects of the variants through transcriptomic analysis of patient fibroblasts. METHODS: We performed exome, targeted capture, and Sanger sequencing of patients with undiagnosed developmental disorders, in multiple independent diagnostic or research centers. Phenotypic and mutational comparisons were facilitated through data exchange platforms. Whole-transcriptome sequencing was performed on RNA from patient- and control-derived fibroblasts. RESULTS: We identified heterozygous missense variants in TRAF7 as the cause of a developmental delay-malformation syndrome in 45 patients. Major features include a recognizable facial gestalt (characterized in particular by blepharophimosis), short neck, pectus carinatum, digital deviations, and patent ductus arteriosus. Almost all variants occur in the WD40 repeats and most are recurrent. Several differentially expressed genes were identified in patient fibroblasts. CONCLUSION: We provide the first large-scale analysis of the clinical and mutational spectrum associated with the TRAF7 developmental syndrome, and we shed light on its molecular etiology through transcriptome studies.
Assuntos
Deficiência Intelectual , Transcriptoma , Exoma , Células Germinativas , Humanos , Deficiência Intelectual/genética , Mutação de Sentido Incorreto , Fenótipo , Transcriptoma/genética , Peptídeos e Proteínas Associados a Receptores de Fatores de Necrose TumoralRESUMO
Thrombocytopenia-absent radius (TAR) syndrome is characterized by radial defect and neonatal thrombocytopenia. It is caused by biallelic variants of RBM8A gene (1q21.1) with the association of a null allele and a hypomorphic noncoding variant. RBM8A encodes Y14, a core protein of the exon junction complex involved in messenger RNA maturation. To date, only two hypomorphic variants have been identified. We report on a cohort of 26 patients affected with TAR syndrome and carrying biallelic variants in RBM8A. Half patients carried a 1q21.1 deletion and one of the two known hypomorphic variants. Four novel noncoding variants of RBM8A were identified in the remaining patients. We developed experimental models enabling their functional characterization in vitro. Two variants, located respectively in the 5'-untranslated region (5'-UTR) and 3'-UTR regions, are responsible for a diminished expression whereas two intronic variants alter splicing. Our results bring new insights into the molecular knowledge of TAR syndrome and enabled us to propose genetic counseling for patients' families.
Assuntos
Síndrome Congênita de Insuficiência da Medula Óssea/genética , Proteínas de Ligação a RNA/genética , Trombocitopenia/genética , Deformidades Congênitas das Extremidades Superiores/genética , Regiões 5' não Traduzidas , Adolescente , Adulto , Criança , Pré-Escolar , Deleção Cromossômica , Cromossomos Humanos Par 1 , Estudos de Coortes , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Rádio (Anatomia)/patologia , Adulto JovemRESUMO
TBR1, a T-box transcription factor expressed in the cerebral cortex, regulates the expression of several candidate genes for autism spectrum disorders (ASD). Although TBR1 has been reported as a high-confidence risk gene for ASD and intellectual disability (ID) in functional and clinical reports since 2011, TBR1 has only recently been recorded as a human disease gene in the OMIM database. Currently, the neurodevelopmental disorders and structural brain anomalies associated with TBR1 variants are not well characterized. Through international data sharing, we collected data from 25 unreported individuals and compared them with data from the literature. We evaluated structural brain anomalies in seven individuals by analysis of MRI images, and compared these with anomalies observed in TBR1 mutant mice. The phenotype included ID in all individuals, associated to autistic traits in 76% of them. No recognizable facial phenotype could be identified. MRI analysis revealed a reduction of the anterior commissure and suggested new features including dysplastic hippocampus and subtle neocortical dysgenesis. This report supports the role of TBR1 in ID associated with autistic traits and suggests new structural brain malformations in humans. We hope this work will help geneticists to interpret TBR1 variants and diagnose ASD probands.
Assuntos
Transtorno Autístico/genética , Anormalidades Craniofaciais/genética , Deficiência Intelectual/genética , Fenótipo , Proteínas com Domínio T/genética , Adolescente , Adulto , Animais , Transtorno Autístico/patologia , Criança , Pré-Escolar , Cognição , Anormalidades Craniofaciais/patologia , Feminino , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Humanos , Deficiência Intelectual/patologia , Masculino , Camundongos , Mutação , Neocórtex/diagnóstico por imagem , Neocórtex/patologia , Síndrome , Proteínas com Domínio T/metabolismoRESUMO
PURPOSE: Sifrim-Hitz-Weiss syndrome (SIHIWES) is a recently described multisystemic neurodevelopmental disorder caused by de novo variants inCHD4. In this study, we investigated the clinical spectrum of the disorder, genotype-phenotype correlations, and the effect of different missense variants on CHD4 function. METHODS: We collected clinical and molecular data from 32 individuals with mostly de novo variants in CHD4, identified through next-generation sequencing. We performed adenosine triphosphate (ATP) hydrolysis and nucleosome remodeling assays on variants from five different CHD4 domains. RESULTS: The majority of participants had global developmental delay, mild to moderate intellectual disability, brain anomalies, congenital heart defects, and dysmorphic features. Macrocephaly was a frequent but not universal finding. Additional common abnormalities included hypogonadism in males, skeletal and limb anomalies, hearing impairment, and ophthalmic abnormalities. The majority of variants were nontruncating and affected the SNF2-like region of the protein. We did not identify genotype-phenotype correlations based on the type or location of variants. Alterations in ATP hydrolysis and chromatin remodeling activities were observed in variants from different domains. CONCLUSION: The CHD4-related syndrome is a multisystemic neurodevelopmental disorder. Missense substitutions in different protein domains alter CHD4 function in a variant-specific manner, but result in a similar phenotype in humans.
Assuntos
Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Transtornos do Neurodesenvolvimento/genética , Anormalidades Múltiplas/genética , Adolescente , Adulto , Criança , Pré-Escolar , Montagem e Desmontagem da Cromatina/genética , Deficiências do Desenvolvimento/genética , Feminino , Estudos de Associação Genética , Genótipo , Perda Auditiva/genética , Cardiopatias Congênitas/genética , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/genética , Masculino , Megalencefalia/genética , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Anormalidades Musculoesqueléticas/genética , Mutação de Sentido Incorreto/genética , Fenótipo , Síndrome , Fatores de Transcrição/genéticaRESUMO
BACKGROUND: Chronic lymphocytic leukemia (CLL) stratification mainly relies on FISH markers according to Döhner's hierarchical model which includes high-risk FISH markers, intermediate FISH, or low-risk FISH. Recently, complex karyotype (CK) has been demonstrated as an independent negative prognostic factor in CLL. METHODS: A series of 1012 untreated CLL patients have been investigated with both FISH and chromosome banding analysis (CBA) on the same pellet obtained from interleukin IL-2-CPG DSP30 oligonucleotide-stimulated cultured cells. RESULTS: Combining both FISH and CBA has led to refine prognostic categories with identification of 30% of CK in low-risk and intermediate FISH group. This raises the issue of switching them to a high-risk group. While this series confirmed the significant association between CK and high-risk FISH (P = .003), 33% of CK present no ATM or TP53 deletion. Three groups characterized by significant association between FISH markers and CBA have emerged: CK with TP53 loss and monosomy 15; CK with ATM loss and 14q32 translocation; and CK without ATM or TP53 losses but trisomies 12, 18, and 19 or t(14;18)(q32;q21). CONCLUSION: We have observed that in addition to FISH analysis, the CBA allows detection of many abnormalities with potential impact on patient follow-up and treatment, mainly CK.
Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/genética , Deleção de Genes , Leucemia Linfocítica Crônica de Células B/diagnóstico , Leucemia Linfocítica Crônica de Células B/genética , Translocação Genética , Proteína Supressora de Tumor p53/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Bandeamento Cromossômico , Feminino , Humanos , Hibridização in Situ Fluorescente , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Pessoa de Meia-IdadeRESUMO
The NOD2 gene, involved in innate immune responses to bacterial peptidoglycan, has been found to be closely associated with Crohn's Disease (CD), with an Odds Ratio ranging from 3â»36. Families with three or more CD-affected members were related to a high frequency of NOD2 gene variations, such as R702W, G908R, and 1007fs, and were reported in the EPIMAD Registry. However, some rare CD multiplex families were described without identification of common NOD2 linked-to-disease variations. In order to identify new genetic variation(s) closely linked with CD, whole exome sequencing was performed on available subjects, comprising four patients in two generations affected with Crohn's disease without R702W and G908R variation and three unaffected related subjects. A rare and, not yet, reported missense variation of the NOD2 gene, N1010K, was detected and co-segregated across affected patients. In silico evaluation and modelling highlighted evidence for an adverse effect of the N1010K variation with regard to CD. Moreover, cumulative characterization of N1010K and 1007fs as a compound heterozygous state in two, more severe CD family members strongly suggests that N1010K could well be a new risk factor involved in Crohn's disease genetic susceptibility.
Assuntos
Doença de Crohn/genética , Predisposição Genética para Doença , Imunidade Inata/genética , Proteína Adaptadora de Sinalização NOD2/genética , Adolescente , Adulto , Alelos , Criança , Doença de Crohn/imunologia , Doença de Crohn/patologia , Feminino , Estudos de Associação Genética , Genótipo , Heterozigoto , Humanos , Masculino , Mutação , Mutação de Sentido Incorreto/genética , Proteína Adaptadora de Sinalização NOD2/química , Proteína Adaptadora de Sinalização NOD2/imunologia , Peptidoglicano/imunologia , Polimorfismo de Nucleotídeo Único , Conformação Proteica , Sequenciamento do ExomaRESUMO
Clonal chromosome abnormalities in Philadelphia-negative cells could concern chronic myeloid leukemia patients treated by tyrosine kinase inhibitors. The European LeukemiaNet distinguishes -7/del(7q) abnormalities as a "warning". However, the impact of clonal chromosome abnormalities, and specifically those of -7/del(7q), in Philadelphia-negative cells on clinical outcomes is unclear and based on case-reports showing morphological dysplasia and increased risk of acute myeloid leukemia, suggesting the coexistence of chronic myeloid leukemia and high-risk myelodysplastic syndrome. The aim of this study was to determine whether the impact of -7/del(7q) clonal chromosome abnormalities in Philadelphia-negative cells on the clinical outcome is different from that of other types of abnormalities, and we argue for an underlying associated high-risk myelodysplastic syndrome. Among 102 chronic myeloid leukemia patients with clonal chromosome abnormalities in Philadelphia-negative cells with more than a median of 6 years of follow up, patients with -7/del(7q) more frequently had signs of dysplasia, a lower cumulative incidence of deep molecular response and often needed further treatment lines, with the consequent impact on event-free and progression-free survival. Morphological features of dysplasia are associated with myelodysplastic syndrome/acute myeloid leukemia mutations and compromise the optimal response to tyrosine kinase inhibitors, irrespectively of the type of clonal chromosome abnormalities in Philadelphia-negative cells. However, mutation patterns determined by next-generation sequencing could not clearly explain the underlying high-risk disease. We hereby confirm the pejorative prognostic value of -7/del(7q) clonal chromosome abnormalities in Philadelphia-negative cells and suggest that myelodysplastic features constitute a warning signal that response to tyrosine kinase inhibitors may be less than optimal.
Assuntos
Aberrações Cromossômicas , Cromossomos Humanos Par 7 , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/etiologia , Metáfase/genética , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/genética , Alelos , Deleção Cromossômica , Progressão da Doença , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Hibridização in Situ Fluorescente , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Leucemia Mielogênica Crônica BCR-ABL Positiva/terapia , Masculino , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Mutação , Síndromes Mielodisplásicas/mortalidade , Síndromes Mielodisplásicas/terapia , Prognóstico , Análise de SobrevidaRESUMO
We compared immunoglobulin heavy chain gene (IGH) signal patterns in multiple myeloma (MM) using the FGFR3-IGH and the IGH break-apart probes to facilitate their understanding and analysis. Forty-nine patients with MM were studied. FISH was performed on samples sorted with an FGFR3-IGH dual-color, dual-fusion translocation probe and an IGH dual-color break-apart rearrangement probe. The IGH deletions were found in 7 MM analyzed with the FGFR3-IGH probe and all confirmed by the IGH break-apart probe. The additional IGH signals were associated with different patterns using the IGH break-apart probe: a normal pattern in 9 cases, trisomy 14 in 3 cases, and splits of IGH in 7 cases. Fusion patterns with the FGFR3-IGH probe were observed in 13 cases. Atypical patterns were identified in 6 cases with multiple presentations of IGH: a deletion of the IGH variable segment in der(4) or in chromosome 14, loss of the IGH locus in chromosome 14, and additional copies of FGFR3-IGH fusion probes. We identified a majority of atypical IGH patterns with the t(4;14) probe, without false-negative results when FGFR3-IGH signal fusions were found. However, the extrapolation of FGFR3-IGH probe signals requires the IGH break-apart probe to obtain unequivocal interpretations.
Assuntos
Cadeias Pesadas de Imunoglobulinas/genética , Mieloma Múltiplo/genética , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/genética , Translocação Genética/genética , Pontos de Quebra do Cromossomo , Cromossomos Humanos Par 14/genética , Cromossomos Humanos Par 4/genética , Humanos , Hibridização in Situ Fluorescente , Sindecana-1/genéticaRESUMO
BACKGROUND: Our aim was to set the FISH combination of del(17p13), t(4;14), 1q21 gain and del(1p32), four adverse cytogenetic factors rarely evaluated together, and compare our technical thresholds with those defined in the literature. METHODS: Two hundred thirty-three patients with MM at diagnosis were studied using FISH to target 4 unfavorable cytogenetic abnormalities: 17p13 deletion, t(4;14) translocation, 1p32 deletion and 1q21 gain. Technical thresholds were determined for each probe using isolated CD138-expressing PC from patients without MM. RESULTS: The FISH analysis identified abnormalities in 79.0% of patients. Del(17p13) was detected in 15.0% of cases, t(4;14) in 11.5%, 1q21 gain in 37.8% and del(1p32) in 8.7%. Adding 1p32/1q21 FISH probes has enabled us to identify adverse cytogenetic profiles in 39.0% of patients without del(17p13) or t(4;14). Clonal heterogeneity was observed in 51.1% of patients as well as an increase in the number of adverse abnormalities when related clones were greater than or equal to 2 (85.1% against 45.6%). CONCLUSION: FISH allowed detecting accumulation of adverse abnormalities and clonal heterogeneity in MM with a combination of 4 probes. The impacts of these two parameters need to be evaluated, and could be included in future cytogenetic classifications.
RESUMO
EVI1 overexpression confers poor prognosis in acute myeloid leukemia (AML). Quantification of EVI1 expression has been mainly assessed by real-time quantitative PCR (RT-qPCR) based on relative quantification of EVI1-1D splice variant. In this study, we developed a RT-qPCR assay to perform quantification of EVI1 expression covering the different splice variants. A sequence localized in EVI1 exons 14 and 15 was cloned into plasmids that were used to establish RT-qPCR standard curves. Threshold values to define EVI1 overexpression were determined using 17 bone marrow (BM) and 31 peripheral blood (PB) control samples and were set at 1% in BM and 0.5% in PB. Samples from 64 AML patients overexpressing EVI1 included in the ALFA-0701 or -0702 trials were collected at diagnosis and during follow-up (n=152). Median EVI1 expression at AML diagnosis was 23.3% in BM and 3.6% in PB. EVI1 expression levels significantly decreased between diagnostic and post-induction samples, with an average variation from 21.6% to 3.56% in BM and from 4.0% to 0.22% in PB, but did not exceed 1 log10 reduction. Our study demonstrates that the magnitude of reduction in EVI1 expression levels between AML diagnosis and follow-up is not sufficient to allow sensitive detection of minimal residual disease.