Differences in DNA methylation status explain phenotypic variability in patients with 5p- syndrome.

Cri Du Chat syndrome, or 5p- syndrome, is characterized by a terminal or interstitial deletion on the short arm of chromosome 5 that causes variable clinical manifestations, including high-pitched cry in newborns, delayed growth, and global development. Different cytogenomic rearrangements, family history, and environmental factors may hinder the genotype-phenotype association. Thus, the phenotypic variability of this syndrome may not be limited only to variations in gene structure, such as deletions and duplications. It is possible that other mechanisms related to the activation or inactivation of promoters and/or exons of actively transcribed genes, such as DNA methylation are involved. Therefore, we studied the genome-wide methylation status profile of peripheral blood samples from fifteen patients with Cri du Chat Syndrome and nine control samples through the array method to look for Differentially Methylated Regions. We found that Differentially Methylated Regions outside the 5p region are mainly associated with regulating gene transcription, splicing, and chromatin remodeling. Most biological pathways are related to transcription, histone and chromatin binding, spliceosome and ribosomal complex, and RNA processing. Our results suggest that changes in the 5p region can cause an imbalance in other chromosomal regions capable of affecting gene modulation and thus explain the phenotypic differences in patients with 5p-.

Establishment and Comprehensive Molecular Characterization of an Immortalized Glioblastoma Cell Line from a Brazilian Patient.

Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults, with few effective treatment strategies. The research on the development of new treatments is often constrained by the limitations of preclinical models, which fail to accurately replicate the disease's essential characteristics. Herein, we describe the obtention, molecular, and functional characterization of the GBM33 cell line. This cell line belongs to the GBM class according to the World Health Organization 2021 Classification of Central Nervous System Tumors, identified by methylation profiling. GBM33 expresses the astrocytic marker GFAP, as well as markers of neuronal origin commonly expressed in GBM cells, such as ßIII-tubulin and neurofilament. Functional assays demonstrated an increased growth rate when compared to the U87 commercial cell line and a similar sensitivity to temozolamide. GBM33 cells retained response to serum starvation, with reduced growth and diminished activation of the Akt signaling pathway. Unlike LN-18 and LN-229 commercial cell lines, GBM33 is able to produce primary cilia upon serum starvation. In summary, the successful establishment and comprehensive characterization of this GBM cell line provide researchers with invaluable tools for studying GBM biology, identifying novel therapeutic targets, and evaluating the efficacy of potential treatments.

Cri-du-Chat Syndrome: Revealing a Familial Atypical Deletion in 5p.

Introduction: Cri-du-chat syndrome is generally diagnosed when patients present a high-pitched cry at birth, microcephaly, ocular hypertelorism, and prominent nasal bridge. The karyotype is useful to confirm deletions in the short arm of chromosome 5 (5p-) greater than 10 Mb. In cases of smaller deletions, it is necessary to resort to other molecular techniques such as fluorescence in situ hybridization, multiplex ligation-dependent probe amplification (MLPA) or genomic array. Case Presentation: We report a family with an atypical deletion in 5p (mother and 2 children) and variable phenotypes compared with the literature. We applied a P064 MLPA kit to evaluate 5p- in the mother and the 2 children, and we used the Infinium CytoSNP-850K BeadChip genomic array to evaluate the siblings, an 11-year-old boy and a 13-year-old girl, to better define the 5p breakpoints. Both children presented a high-pitched cry at birth, but they did not present any of the typical physical features of 5p- syndrome. The MLPA technique with 5 probes for the 5p region revealed that the patients and their mother presented an atypical deletion with only 4 probes deleted (TERT_ex2, TERT_ex13, CLPTM1L, and IRX4). The genomic array performed in the siblings' samples revealed a 6.2-Mb terminal deletion in 5p15.33p15.32, which was likely inherited from their mother, who presented similar molecular features, seen in MLPA. Discussion: The sparing of the CTNND2 gene, which is associated with cerebral development, in both siblings may explain why these 2 patients had features such as better communication skills which most patients with larger 5p deletions usually do not present. In addition, both patients had smaller deletions than those found in patients with a typical 5p- phenotype. This report demonstrates the utility of genomic arrays as a diagnostic tool to better characterize atypical deletions in known syndromes such as 5p- syndrome, which will allow a better understanding of the genotype-phenotype correlations.

Novel FERMT3 and PTPRQ Mutations Associated with Leukocyte Adhesion Deficiency-III and Sensorineural Hearing Loss.

Leukocyte adhesion deficiency-III (LAD-III) is a rare genetic disease caused by defective integrin activation in hematopoietic cells due to mutations in the FERMT3 gene. The PTPRQ gene encodes the protein tyrosine phosphatase receptor Q and is essential for the normal maturation and function of hair bundle in the cochlea. Homozygous PTPRQ mutations impair the stereocilia in hair cells which lead to nonsyndromic sensorineural hearing loss (SNHL) with vestibular dysfunction. Here, we report two novel pathogenic homozygous mutations found in two genes, FERMT3 and PTPRQ , in a Brazilian patient with LAD-III and SNHL, which may develop our understanding of the phenotype-genotype correlation and prognosis of patients with these rare diseases.

Comprehensive Genetic Analysis of 128 Candidate Genes in a Cohort With Idiopathic, Severe, or Familial Osteoporosis.

CONTEXT: The genetic bases of osteoporosis (OP), a disorder with high heritability, are poorly understood at an individual level. Cases of idiopathic or familial OP have long puzzled clinicians as to whether an actionable genetic cause could be identified. OBJECTIVE: We performed a genetic analysis of 28 cases of idiopathic, severe, or familial osteoporosis using targeted massively parallel sequencing. DESIGN: Targeted sequencing of 128 candidate genes was performed using Illumina NextSeq. Variants of interest were confirmed by Sanger sequencing or SNP array. PATIENTS AND SETTING: Thirty-seven patients in an academic tertiary hospital participated (54% male; median age, 44 years; 86% with fractures), corresponding to 28 sporadic or familial cases. MAIN OUTCOME MEASURE: The identification of rare stop-gain, indel, splice site, copy-number, or nonsynonymous variants altering protein function. RESULTS: Altogether, we identified 28 variants of interest, but only 3 were classified as pathogenic or likely pathogenic variants: COL1A2 p.(Arg708Gln), WNT1 p.(Gly169Asp), and IDUA p.(His82Gln). An association of variants in different genes was found in 21% of cases, including a young woman with severe OP bearing WNT1, PLS3, and NOTCH2 variants. Among genes of uncertain significance analyzed, a potential additional line of evidence has arisen for GWAS candidates GPR68 and NBR1, warranting further studies. CONCLUSIONS: While we hope that continuing efforts to identify genetic predisposition to OP will lead to improved and personalized care in the future, the likelihood of identifying actionable pathogenic variants in intriguing cases of idiopathic or familial osteoporosis is seemingly low.

Application of Whole-Exome Sequencing in Detecting Copy Number Variants in Patients with Developmental Delay and/or Multiple Congenital Malformations.

Overcoming challenges for the unambiguous detection of copy number variations is essential to broaden our understanding of the role of genomic variants in the clinical phenotype. With the improvement of software and databases, whole-exome sequencing quickly can become an excellent strategy in the routine diagnosis of patients with a developmental delay and/or multiple congenital malformations. However, even after a detailed analysis of pathogenic single-nucleotide variants and indels in known disease genes, using whole-exome sequencing, some patients with suspected syndromic conditions are left without a conclusive diagnosis. These negative results could be the result of different factors including nongenetic etiologies, lack of knowledge about the genes that cause different disease phenotypes, or, in some cases, a deletion or duplication of genomic information not routinely detectable by whole-exome sequencing variant calling. Although copy number variant detection is possible using whole-exome sequencing data, such analysis presents significant challenges and cannot yet be used to replace chromosomal arrays for identification of deletions or duplications.

Gene expression profile suggesting immunological dysregulation in two Brazilian Bloom's syndrome cases.

BACKGROUND: Bloom syndrome (BS) is a rare autosomal recessive chromosome instability disorder. The main clinical manifestations are growth deficiency, telangiectasic facial erythema, immunodeficiency, and increased risk to develop neoplasias at early age. Cytogenetic test for sister chromatid exchanges (SCEs) is used as a diagnostic marker for BS. In addition, most patients also present mutations in the BLM gene, related to defects in the DNA repair mechanism. However, the molecular mechanism behind the pathogenicity of BS is still not completely understood. METHODS: We describe two patients confirmed with BS by SCE and molecular analysis. Also, we performed the gene expression profile by the RNA-seq methodology in mRNA transcripts for differential gene expression analysis using as a biological condition for comparison BS versus health controls. RESULTS: We detected 216 differentially expressed genes related to immunological pathways such as positive regulation and activation of B cells, immune effector process and absence of difference of DNA repair genes expression. In addition; we also observed differentially expressed genes associated with apoptosis control, such as BCL2L1, CASP7, CDKN1A, E2F2, ITPR, CD274, TNFAIP6, TNFRSF25, TNFRSF13C, and TNFRSF17. CONCLUSION: Our results suggest that the combination of altered expression of genes involved in signaling pathways of immune response and apoptosis control may contribute directly to the main characteristics observed in BS, such as recurrent infections, growth failure, and high risk of cancer. Transcriptome studies of other instability syndromes could allow a more accurate analysis of the relevant gene interactions associated with the destabilization of the genome. This is a first description of the profile of differential gene expression related to immunological aspects detected in patients with BS by RNA-seq.

Breakpoint delineation in 5p- patients leads to new insights about microcephaly and the typical high-pitched cry.

BACKGROUND: Cri du chat syndrome (CdCS) is a rare syndrome caused by a partial or complete deletion of the short arm of chromosome 5 (5p-). The main clinical features include a high-pitched cry, facial asymmetry, microcephaly, round face at birth, epicanthal folds, hypotonia, delayed growth and development. METHODS: We studied 14 Brazilian patients with CdCS using genomic array in order to better define the 5p breakpoints and recognize copy number variations (CNVs) that contribute to clinical manifestations associated with the syndrome. RESULTS: Array confirmed terminal deletions in 13 patients and an interstitial deletion in one patient. It was also possible to map the breakpoints and associate a genomic region of 4.7 Mb to the development of head circumference and cat-like cry. We also found other CNVs concomitant to the 5p deletion including a 9p duplication, a 17q deletion, and a 22q deletion in three different patients. CONCLUSION: With advancements of molecular cytogenomic methods in the last two decades, it was possible to evidence cryptic alterations and improve the genotype-phenotype correlation. In this work, we describe a new genomic region associated with microcephaly and cat-like cry and highlight the importance of precise delineation of 5p deletion breakpoints and detection of other CNVs in CdCS patients to improve genotype-phenotype correlation to perform a complete clinical and molecular diagnosis.

Mosaic Trisomy 12 Associated with Overgrowth Detected in Fibroblast Cell Lines.

Mosaic trisomy 12 is a rare anomaly, and only 9 cases of live births with this condition have been reported in the literature. The clinical phenotype is variable, including neuropsychomotor developmental delay, congenital heart disease, microcephaly, cutaneous spots, facial asymmetry, prominent ears, hypotonia, retinopathy, and sensorineural hearing loss. A 2-year-old female presented with neuropsychomotor developmental delay, prominent forehead, dolichocephaly, patchy skin pigmentation, and unexpected overgrowth at birth. Cytogenetic analysis of her peripheral blood showed normal results, suggesting the presence of a chromosomal alteration in other tissues. Further studies using G-banding and FISH performed on fibroblasts from both hyper- and hypopigmented regions identified a 47,XX,+12/46,XX karyotype. To the best of our knowledge, no patients with mosaic trisomy 12 associated with overgrowth have been reported to date. Congenital overgrowth and neonatal overgrowth have been frequently linked to Pallister-Killian syndrome (PKS; OMIM 601803). This case suggests the possibility of an association of genes present in the 12p region with fetal overgrowth, considering that chromosomal duplications could lead to an increase in the production of aberrant transcripts and disturbing gene dosage effects. This case highlights the importance of cytogenetic analysis in different tissues to provide relevant information to the specific genotype/phenotype correlation.

Subtelomeric Copy Number Variations: The Importance of 4p/4q Deletions in Patients with Congenital Anomalies and Developmental Disability.

The most prevalent structural variations in the human genome are copy number variations (CNVs), which appear predominantly in the subtelomeric regions. Variable sizes of 4p/4q CNVs have been associated with several different psychiatric findings and developmental disability (DD). We analyzed 105 patients with congenital anomalies (CA) and developmental and/or intellectual disabilities (DD/ID) using MLPA subtelomeric specific kits (P036 /P070) and 4 of them using microarrays. We found abnormal subtelomeric CNVs in 15 patients (14.3%), including 8 patients with subtelomeric deletions at 4p/4q (53.3%). Additional genomic changes were observed at 1p36, 2q37.3, 5p15.3, 5q35.3, 8p23.3, 13q11, 14q32.3, 15q11.2, and Xq28/Yq12. This indicates the prevalence of independent deletions at 4p/4q, involving PIGG, TRIML2, and FRG1. Furthermore, we identified 15 genes with changes in copy number that contribute to neurological development and/or function, among them CRMP1, SORCS2, SLC25A4, and HELT. Our results highlight the association of genes with changes in copy number at 4p and 4q subtelomeric regions and the DD phenotype. Cytogenomic characterization of additional cases with distal deletions should help clarifying the role of subtelomeric CNVs in neurological diseases.

Rare genomic rearrangement in a boy with Williams-Beuren syndrome associated to XYY syndrome and intriguing behavior.

Williams-Beuren syndrome (WBS) is caused by a hemizygous contiguous gene microdeletion of 1.55-1.84 Mb at 7q11.23 region. Approximately, 28 genes have been shown to contribute to classical phenotype of SWB with presence of dysmorphic facial features, supravalvular aortic stenosis (SVAS), intellectual disability, and overfriendliness. With the use of Microarray-based comparative genomic hybridization and other molecular cytogenetic techniques, is possible define with more accuracy partial or atypical deletion and refine the genotype-phenotype correlation. Here, we report on a rare genomic structural rearrangement in a boy with atypical deletion in 7q11.23 and XYY syndrome with characteristic clinical signs, but not sufficient for the diagnosis of WBS. Cytogenetic analysis of G-banding showed a karyotype 47,XYY. Analysis of DNA with the technique of MLPA (Multiplex Ligation-dependent Probe Amplification) using kits a combination of kits (P064, P036, P070, and P029) identified an atypical deletion on 7q11.23. In addition, high resolution SNP Oligonucleotide Microarray Analysis (SNP-array) confirmed the alterations found by MLPA and revealed others pathogenic CNVs, in the chromosomes 7 and X. The present report demonstrates an association not yet described in literature, between Williams-Beuren syndrome and 47,XYY. The identification of atypical deletion in 7q11.23 concomitant to additional pathogenic CNVs in others genomic regions allows a better comprehension of clinical consequences of atypical genomic rearrangements.

Cytogenomic delineation and clinical follow-up of 10 Brazilian patients with Pallister-Killian syndrome.

BACKGROUND: Pallister-Killian syndrome (PKS) is a sporadic genetic disorder caused by the presence of a tissue-specific mosaicism for isochromosome 12p - i(12) (p10) and is characterized by facial dysmorphism including coarse facies, upslanting palpebral fissures, bitemporal alopecia, pigmentary skin anomalies, developmental delay, hypotonia and seizures. Although typical clinical features of PKS commonly exist, clinicians often do not raise the possibility of this diagnosis. RESULTS: We reviewed the medical records of 10 patients with confirmed PKS followed in our service (since 1990 to 2015). Age at diagnosis varied from prenatal to 3 years and clinical features were consistent with those described in the literature. In all patients, peripheral blood karyotypes were normal and cytogenomic study was performed in order to confirm the diagnosis. Three of these patients had PKS diagnosis confirmed by buccal smear MLPA. CONCLUSION: An early conclusion from our results demonstrated that MLPA on buccal smears is a good and non-invasive method to detect extra copies of 12p and should be considered as the first exam, before a skin biopsy for a fibroblast karyotype is performed.

45,X karyotype in an infertile man: how is this possible?

The case was male, 32 years old, with a nonobstructive azoospermia diagnosis and an initial 45,X karyotype. We evaluated by classical cytogenetic methods, C and NOR banding, fluorescent in situ hybridization, and polymerase chain reaction investigations. After investigation, we found the following karyotype: 45,X,dic(Y;22)(q11.223;p11.2). This investigation contributes to our understanding of how chromosome rearrangements can influence fertility processes and how important it is to perform a cytogenetic analysis in infertility cases.

Congenital Heart Disease as a Warning Sign for the Diagnosis of the 22q11.2 Deletion / Cardiopatias Congênitas como um Sinal de Alerta para o Diagnóstico da Deleção do 22q11.2

Background: To alert for the diagnosis of the 22q11.2 deletion syndrome (22q11.2DS) in patients with congenital heart disease (CHD). Objective: To describe the main CHDs, as well as phenotypic, metabolic and immunological findings in a series of 60 patients diagnosed with 22q11.2DS. Methods: The study included 60 patients with 22q11.2DS evaluated between 2007 and 2013 (M:F=1.3, age range 14 days to 20 years and 3 months) at a pediatric reference center for primary immunodeficiencies. The diagnosis was established by detection of the 22q11.2 microdeletion using FISH (n = 18) and/or MLPA (n = 42), in association with clinical and laboratory information. Associated CHDs, progression of phenotypic facial features, hypocalcemia and immunological changes were analyzed. Results: CHDs were detected in 77% of the patients and the most frequent type was tetralogy of Fallot (38.3%). Surgical correction of CHD was performed in 34 patients. Craniofacial dysmorphisms were detected in 41 patients: elongated face (60%) and/or elongated nose (53.3%), narrow palpebral fissure (50%), dysplastic, overfolded ears (48.3%), thin lips (41.6%), elongated fingers (38.3%) and short stature (36.6%). Hypocalcemia was detected in 64.2% and decreased parathyroid hormone (PTH) level in 25.9%. Decrease in total lymphocytes, CD4 and CD8 counts were present in 40%, 53.3% and 33.3%, respectively. Hypogammaglobulinemia was detected in one patient and decreased concentrations of immunoglobulin M (IgM) in two other patients. Conclusion: Suspicion for 22q11.2DS should be raised in all patients with CHD associated with hypocalcemia and/or facial dysmorphisms, considering that many of these changes may evolve with age. The 22q11.2 microdeletion should be confirmed by molecular testing in all patients. .

Fundamento: Alertar para o diagnóstico da síndrome da deleção 22q11.2 (SD 22q11.2) em pacientes com cardiopatias congênitas. Objetivo: Descrever as principais cardiopatias, alterações fenotípicas, metabólicas e imunológicas em uma série de 60 pacientes com a SD22q11.2. Métodos: Foram incluídos 60 pacientes com SD22q11.2 avaliados entre 2007 e 2013 (M:F = 1,3; idades entre 14 dias a 20 anos e 3 meses) em um centro pediátrico de referência para imunodeficiências primárias. O diagnóstico foi feito pela detecção da microdeleção 22q11.2 através de FISH (n = 18) e/ou MLPA (n = 42), associados a dados clínicos e laboratoriais. Foram analisadas as cardiopatias, aspectos fenotípicos evolutivos da fácies, a hipocalcemia e alterações imunológicas associadas. Resultados: Cardiopatias congênitas ocorreram em 77% dos casos, sendo que a tetralogia de Fallot ocorreu em 38,3%. Correção cirúrgica da cardiopatia foi realizada em 34 pacientes. Os dismorfismos craniofaciais foram detectados em 41 pacientes: face (60%) e/ou nariz alongados (53,3%), fenda palpebral estreita (50%), orelhas displásicas com hiperdobramento (48,3%), lábios finos (41,6%), dedos alongados (38,3%) e baixa estatura (36,6%). Hipocalcemia foi observada em 64,2% com redução do nível de paratormônio (PTH) em 25,9%. Observou-se número reduzido de linfócitos totais, CD4 e CD8 em 40%, 53,3%, e 33,3%, respectivamente. Detectou-se hipogamaglobulinemia em um paciente e redução das concentrações de imunoglobulina M (IgM) em outros dois pacientes. Conclusão: Deve-se suspeitar da SD22q11.2 em todos os portadores de cardiopatia congênita com hipocalcemia e/ou dismorfismos faciais, ressaltando-se que muitas dessas alterações podem ser evolutivas. ...

Congenital Heart Disease as a Warning Sign for the Diagnosis of the 22q11.2 Deletion.

Background: To alert for the diagnosis of the 22q11.2 deletion syndrome (22q11.2DS) in patients with congenital heart disease (CHD). Objective: To describe the main CHDs, as well as phenotypic, metabolic and immunological findings in a series of 60 patients diagnosed with 22q11.2DS. Methods: The study included 60 patients with 22q11.2DS evaluated between 2007 and 2013 (M:F=1.3, age range 14 days to 20 years and 3 months) at a pediatric reference center for primary immunodeficiencies. The diagnosis was established by detection of the 22q11.2 microdeletion using FISH (n = 18) and/or MLPA (n = 42), in association with clinical and laboratory information. Associated CHDs, progression of phenotypic facial features, hypocalcemia and immunological changes were analyzed. Results: CHDs were detected in 77% of the patients and the most frequent type was tetralogy of Fallot (38.3%). Surgical correction of CHD was performed in 34 patients. Craniofacial dysmorphisms were detected in 41 patients: elongated face (60%) and/or elongated nose (53.3%), narrow palpebral fissure (50%), dysplastic, overfolded ears (48.3%), thin lips (41.6%), elongated fingers (38.3%) and short stature (36.6%). Hypocalcemia was detected in 64.2% and decreased parathyroid hormone (PTH) level in 25.9%. Decrease in total lymphocytes, CD4 and CD8 counts were present in 40%, 53.3% and 33.3%, respectively. Hypogammaglobulinemia was detected in one patient and decreased concentrations of immunoglobulin M (IgM) in two other patients. Conclusion: Suspicion for 22q11.2DS should be raised in all patients with CHD associated with hypocalcemia and/or facial dysmorphisms, considering that many of these changes may evolve with age. The 22q11.2 microdeletion should be confirmed by molecular testing in all patients.

Complex small supernumerary marker chromosome with a 15q/16p duplication: clinical implications.

BACKGROUND: Complex small supernumerary marker chromosomes (sSMCs) consist of chromosomal material derived from more than one chromosome and have been implicated in reproductive problems such as recurrent pregnancy loss. They may also be associated with congenital abnormalities in the offspring of carriers. Due to its genomic architecture, chromosome 15 is frequently associated with rearrangements and the formation of sSMCs. Recently, several different CNVs have been described at 16p11.2, suggesting that this region is prone to rearrangements. RESULTS: We detected the concomitant occurrence of partial trisomy 15q and 16p, due to a complex sSMC, in a 6-year-old girl with clinical phenotypic. The karyotype was analyzed by G and C banding, NOR staining, FISH and SNP array and defined as 47,XX,+der(15)t(15;16)(q13;p13.2)mat. The array assay revealed an unexpected complex sSMC containing material from chromosomes 15 and 16, due to an inherited maternal translocation (passed along over several generations). The patient's phenotype included microsomia, intellectual disability, speech delay, hearing impairment, dysphagia and other minor alterations. DISCUSSION: This is the first report on the concomitant occurrence of partial trisomy 15q and 16p. The wide range of phenotypes associated with complex sSMCs represents a challenge for genotype-phenotype correlation studies, accurate clinical assessment of patients and genetic counseling.

Single-nucleotide polymorphism array-based characterization of ring chromosome 18.

OBJECTIVE: To study genotype-phenotype correlation of ring chromosome 18 [r(18)] in 9 patients with 46,XN karyotype. STUDY DESIGN: In 9 patients with a de novo 46,XN,r(18) karyotype (7 females, 2 males), we performed high-resolution single-nucleotide polymorphism array analysis (Illumina Human Omni1-QuadV1 array in 6 patients, Affymetrix 6.0 array in 3 patients), investigation of parental origin, and genotype-phenotype correlation. RESULTS: No breakpoint was recurrent. Single metaphases with loss of the ring, double rings, or secondarily rearranged rings were found in some cases, but true mosaicism was present in none of these cases. In 3 patients, additional duplications in 18p (of 1.4 Mb, 2 Mb, and 5.8 Mb) were detected. In 1 patient, an additional deletion of 472 kb in Xp22.33, including the SHOX gene, was found. Parental origin of r(18) was maternal in 2 patients and paternal in 4 patients, and formation was most likely meiotic. Karyotype was normal in all investigated parents (n = 15). At birth, mean maternal age was 30 years (n = 9) and mean paternal age was 34.4 years (n = 9). CONCLUSION: Genotype-phenotype correlation revealed extensive clinical variability but no characteristic r(18) phenotype. Severity of clinical signs were generally correlated with the size of the deletion. Patients with large deletions in 18p and small deletions in 18q exhibited mainly symptoms related to 18p-, whereas those with large deletions in 18q and small deletions in 18p had symptoms of 18q-.

Efficacy of two fluorescence in situ hybridization (FISH) probes for diagnosing malignant pleural effusions.

It is difficult to differentiate tumor cells in pleural fluid from reactive benign mesothelium. Fluorescence in situ hybridization (FISH) can increase diagnostic accuracy. Two hundred pleural fluid samples were analyzed by using FISH probes for chromosomes 11 and 17. Histological analysis was used to diagnose cancer. Clinical, radiological, and histological data were used to exclude malignancy. Eighty-two pleural effusion samples had positive cytology, 51 were benign, and 67 were atypical, but inconclusive. The 82 positive cases were confirmed to be malignant. Among the 51 negative cytology cases, videothoracoscopy-guided pleural biopsy revealed malignancy in three; aneuploid cells were detected by FISH in all cases. In 43 of the 67 cases with inconclusive cytology, malignancy was confirmed based on histology and fluorescence in situ hybridization. One case of parapneumonic effusion with no evidence of cancer during clinical follow-up had a suspicious cytology and positive fluorescence in situ hybridization result. The remaining 23 cases had no histological, radiological, clinical, or genetic evidence of malignancy. This study demonstrated that cytogenetic analysis of fresh pleural fluid samples using only two FISH probes is a valuable ancillary method for the identification of malignant pleural effusion, particularly in cases in which oncotic cytology is inconclusive.

Twenty-year cytogenetic and molecular follow-up of a patient with ring chromosome 15: a case report.

INTRODUCTION: Ring chromosome 15 is a rare disorder, with only a few over 40 cases reported in the literature. There are only two previous reports of cases where patients with ring chromosome 15 have been followed-up. CASE PRESENTATION: We report here on the 20-year clinical and cytogenetic follow-up of a patient with a ring chromosome 15. Our patient, a Caucasoid Asian woman, presented with short stature, microcephaly, minor dysmorphic features, hyperextensible knees, generalized hirsutism, café-au-lait and small hypochromic spots spread over her face and the front of her chest and abdomen, dorsolumbar scoliosis and mild intellectual disability. She was followed-up from the age of eight to 28 years. When she was 27 years old, she was reported by her mother to present with compulsive overeating and an aggressive mood when challenged. Karyotyping revealed that the majority of her cells harbored one normal chromosome and one ring chromosome. Silver staining revealed the presence of the nucleolar organizer region in the ring chromosome. Ring loss and/or secondary aberrations exhibited a slight increase over time, from 4.67% in 1989 to 7.67% in 2009, with the presence of two monocentric rings, cells with interlocked rings, a dicentric ring, and broken or open rings. A genome-wide array technique detected a 5.5Mb deletion in 15q26.2. CONCLUSIONS: We observed that some phenotypic alterations in our patient can be associated with gene loss and haploinsufficiency. Other features may be related to different factors, including ring instability and epigenetic factors.