Myelin is an essential structure that facilitates rapid saltatory conduction in the nervous system. Discrepancies in myelin microstructure are a hallmark of numerous neurological disorders, rendering the assessment of myelin integrity and content an indispensable tool in clinical diagnostics and neuroscience research. Extensive research has been dedicated to scrutinizing its biochemical makeup and morphology under normal, pathological, and experimental conditions over the years. In this review, we present an updated summary of the myelin sheath's structure, composition, and developmental trajectory. We systematically enumerate and contrast eight prevalent myelin staining techniques across dimensions of sensitivity, specificity, and resolution, delving into their underlying staining principles. With an initial application of myelin histology on the mouse demyelination model, our review accentuates the accurate delineation of myelination and the microstructural analysis of the myelin sheath. Such insights are anticipated to significantly contribute to the evaluation and understanding of white matter pathologies.
Myelin Sheath/metabolism* ; Animals ; Humans ; Demyelinating Diseases/pathology* ; Staining and Labeling/methods*

Objective To summarize the clinicopathological features,immunohistochemical characteristics,HOX transcript antisense RNA(HOTAIR)in situ hybridization status,treatment,and prognosis of myxopapillary ependymoma(MPE). Methods A total of 17 patients diagnosed with MPE based on pathological evidence in the Department of Pathology of Peking Union Medical College Hospital from November 2006 to July 2023 were selected,and the clinicopathological data of these patients were collected.Immunohistochemical staining for trimethylation at lysine 27 of histone H3 (H3K27me3),glial fibrillary acidic protein(GFAP),and epithelial membrane antigen(EMA)and alcian blue-periodic acid Schiff(AB-PAS)staining were performed in all the patients.Sixteen patients with spinal ependymomas were selected as the control group.Tissue microarrays were prepared from 17 MPE patients and the control group.HOTAIR ISH was performed and semi-quantitatively scored,and the scores of the two groups were compared by the Wilcoxon rank-sum test. Results The 17 MPE patients aged 14-64 years,with the mean age of(37.48±16.10)years and the male-to-female ratio of 0.7∶1.Their clinical manifestations mainly included lumbosacral and lower limb pains.Microscopically,tumor cells were arranged in a papillary pattern around fibrovascular axis,with abundant myxoid materials,and tumor cells were arranged in a loose meshwork in some patients.The immunohistochemical staining results showed that 17(100%),10(58.82%),and 8(47.06%)patients expressed GFAP,EMA,and D2-40,respectively,and 2(11.76%)patients lacked expression of H3K27me3.AB-PAS staining showed blue myxoid materials in all the 17(100%)patients.HOTAIR was expressed in both MPE and control groups,with higher semi-quantitative score in the MPE group than in the control group(P=0.004).Twelve patients were followed up,with a median follow-up period of 65.50 months,during which three patients showed recurrence.Conclusions MPE exhibits typical pathological features,and the combination with immunohistochemical staining for GFAP and EMA as well as AB-PAS staining facilitates diagnosis of this disease.A small number of patients loss the expression of H3K27me3.HOTAIR is highly expressed in MPE but lacks specificity,which limits its auxiliary diagnostic value.The overall prognosis of MPE is favorable,with a few patients experiencing recurrence.
Humans ; Ependymoma/metabolism* ; Male ; Adult ; Female ; Adolescent ; Middle Aged ; In Situ Hybridization ; Young Adult ; RNA, Antisense/genetics* ; Immunohistochemistry ; Prognosis

OBJECTIVE: To explore the molecular cytogenetic characteristics of three fetuses with psu idic(Y)(q11.22) using a combination of multiple methods. METHODS: A total of 11 000 pregnant women who underwent prenatal diagnosis at the Prenatal Diagnosis Center of Taizhou City from January 2019 to October 2024 were selected as the study subjects. Chromosome karyotype analysis (G-banding) and copy number variation analysis based on next-generation sequencing (NGS) were performed on the amniotic fluid/cord blood samples of the 11 000 fetuses. For cases suspected of Y chromosome abnormalities, C-banding and/or fluorescence in situ hybridization (FISH) and AZF microdeletion testing were additionally conducted. This study has been reviewed and approved by the Medical Ethics Committee of Taizhou Hospital, Zhejiang Province (Ethics No. KL20240860). RESULTS: Among the 11,000 prenatal samples undergoing concurrent karyotype and copy number variation analysis, two fetuses with 45,X/46,X,psu idic(Y)(q11.22) mosaicism and one fetus with 46,X,psu idic(Y)(q11.22) were detected. FISH detection indicated that approximately 66.7% of the cells in fetus 2 exhibited a dicentric Y chromosome, and the metaphase karyotype supported the presence of a pseudodicentric chromosome. AZF testing revealed complete deletion of the AZFb+AZFc regions in fetus 2 and fetus 3. CONCLUSION Conventional G-banding karyotype analysis for psu idic(Y)(q11.22) is prone to misdiagnosis or missed diagnosis. The combined application of chromosome karyotype analysis (G+C banding), copy number variation analysis, and FISH detection in clinical practice can accurately diagnose fetuses with psu idic(Y).
Humans ; Female ; Pregnancy ; Prenatal Diagnosis/methods* ; DNA Copy Number Variations/genetics* ; Adult ; Chromosomes, Human, Y/genetics* ; Karyotyping ; In Situ Hybridization, Fluorescence ; Cytogenetic Analysis/methods* ; Fetus ; High-Throughput Nucleotide Sequencing ; Male

OBJECTIVE: To assess the value of chromosomal microarray analysis (CMA) for the detection of low-level mosaicisms in amniotic fluid samples, and to retrospectively analyze the rare cases of mosaicisms. METHODS: Chromosomal karyotype of the fetus was determined by G-banding analysis of cultured amniotic fluid cells. CMA was used to detect copy number variation of fetal chromosomes, and fluorescence in situ hybridization (FISH) was used to determine the proportion of fetal chromosomal mosaicisms in uncultured amniotic fluid cells. RESULTS: Among 825 prenatal samples, 4 cases of true fetal mosaicisms were detected, which yielded an incidence of 0.48%. Two cases were sex chromosomal mosaicisms, and two were autosomal mosaicisms, which involved chromosomes 8 and 9, respectively. All cases were verified by G-banding analysis of cultured amniotic fluid cells, CMA, and/or FISH. CONCLUSION CMA has a great value for detecting low-level mosaicisms in amniotic fluid samples, though the positive results need to be verified by other techniques and should be interpreted with caution. The review of rare cases can provide a basis for prenatal genetic counseling.
Humans ; Female ; Amniotic Fluid/metabolism* ; Pregnancy ; Mosaicism/embryology* ; Prenatal Diagnosis/methods* ; Adult ; In Situ Hybridization, Fluorescence ; Microarray Analysis/methods* ; Karyotyping ; Retrospective Studies ; Male

OBJECTIVE: To explore the clinical characteristics and genetic factors in four patients with Disorder of sex development (DSD). METHODS: Four patients who visited Tianjin Medical University General Hospital between January 2023 and January 2024, presenting with short stature, abnormal external genitalia, or infertility as their chief complaints, were selected as the study subjects. Clinical data were collected, and peripheral or umbilical cord blood samples were obtained for karyotyping analysis and low-depth whole-genome sequencing (CNV-seq). Quantitative fluorescence PCR (QF-PCR) was used to detect the sex-determining region Y (SRY) gene and azoospermia factor (AZF) on the Y chromosome, while fluorescence in situ hybridization (FISH) was employed to determine the location of the SRY gene. Whole exome sequencing (WES) was performed for genetic testing, and Sanger sequencing was used for familial validation of the candidate variants. The study procedure and protocol were approved by the Medical Ethics Committee of Tianjin Medical University General Hospital (Ethics No.: IRB2024-WZ-006). RESULTS: Case 1 had a karyotype of 45,X[22]/46,XY[8], with CNV-seq indicating a mosaic deletion of 7.44 Mb (copy number = 0.2) at Yp11.31-p11.2, a mosaic deletion of 5.32 Mb (copy number = 0.3) at Yq11.1-q11.221, and a deletion of 10.26 Mb (copy number = 0) at Yq11.221-q11.23. Y chromosome microdeletion analysis showed SRY and AZFa (+), AZFb+c (-). Case 2 had a karyotype of 45,X[12]/46,X,del(X)(q26.3)[18], with CNV-seq indicating a mosaic deletion of 132.62 Mb (copy number = 1.4) at Xp22.33-q26.3 and a deletion of 19.62 Mb (copy number = 1) at Xq26.3-q28. Case 3 had a karyotype of 46,XX, with CNV-seq showing two copies of the X chromosome and no Y chromosome. Y chromosome microdeletion analysis showed SRY (+) and AZFa+b+c (-), and FISH confirmed a translocation of the SRY gene to the terminal end of the short arm of the X chromosome. Case 4 had a karyotype of 46,XY, with CNV-seq showing one copy each of the X and Y chromosomes. Y chromosome microdeletion analysis showed SRY(+) and AZFa+b+c (+), and WES revealed a c.1103del variant in the AR gene (maternal origin), which was classified as a pathogenic variant based on the guidelines from the American College of Medical Genetics and Genomics (ACMG) (PVS1+PP1+PM2_Supporting). CONCLUSION The combined application of multiple detection techniques such as chromosomal karyotyping analysis, CNV-seq, QF-PCR, and WES can identify the genetic etiology of DSD patients, providing a basis for clinical consultation and treatment plan formulation.
Humans ; Male ; Female ; Chromosomes, Human, Y/genetics* ; Disorders of Sex Development/genetics* ; Sex-Determining Region Y Protein/genetics* ; Karyotyping ; In Situ Hybridization, Fluorescence ; Exome Sequencing ; Adult ; Child

OBJECTIVE: To explore the reasons for false negative results by Optical genome mapping (OGM) analysis of three cases and propose strategies for handling them. METHODS: Three patients presented at the Affiliated Hospital of Nantong University between July 2022 and July 2024 were selected as study subjects. The patients included a 37-year-old female with two miscarriages, a 1.5-year-old boy with delayed motor development, and a 35-year-old male whose son had intellectual disability. The patients had undergone comprehensive evaluation with chromosomal karyotyping analysis, single nucleotide polymorphism microarray (SNP array) assay, fluorescence in situ hybridization (FISH), and methylation-specific multiple ligation-dependent probe amplification (MS-MLPA). A retrospective analysis was also carried out on the results of OGM testing. This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: 2020-K004). RESULTS: The chromosomal karyotype of patient 1 was 46,XX,4qs, and no abnormality was found by SNP array, FISH, and OGM testing. Patient 2 had a normal chromosomal karyotype, and SNP array analysis did not reveal any copy number abnormalities of chromosomal fragments but the presence of a homozygous region of approximately 79.58 Mb at 15q11.2-q26.3 (chr15: 22817871_102397317). MS-MLPA detection indicated that the copy number of the 15q11.2-q13 region was 2, and the degree of methylation was relatively high (average ratio = 1.0). OGM detection confirmed the presence of approximately 67.97 Mb of homozygosity in the chr15:33814680_101787650 [hg38] region of 15q14-q26.3. Patient 3 had a chromosomal karyotype of 46,XY,t(9;14)(q13;q11.2). No abnormality was found by OGM testing for patients 1 and 3. CONCLUSION As a novel cytogenetic technique, OGM can achieve high-resolution and high-precision analysis for numerical and structural genomic abnormalities. Nevertheless, it also has certain limitations, as its false negative results are related to factors such as the type of genomic variation, the chromosomal regions involved in the variation, the type of disease, and the version of human reference genome. Currently, it cannot be used as an independent method for the diagnosis of genetic diseases.
Humans ; Male ; Female ; Adult ; Polymorphism, Single Nucleotide/genetics* ; Karyotyping ; Chromosome Mapping/methods* ; Infant ; False Negative Reactions ; In Situ Hybridization, Fluorescence

OBJECTIVE: To investigate the clinical characteristics and genetic etiology of a male with a normal phenotype and SRY gene-positive 46,XX/46,XY tetrazoospermia chimerism. METHODS: A male patient with an abnormal peripheral blood chromosomal karyotype detected at the Infertility Center of Taizhou Hospital of Zhejiang Province on December 2, 2013 was selected as the study subject. Peripheral venous blood samples were collected from the proband and his family members, together with a semen sample from the proband. Chromosomal karyotype analysis, red blood cell blood group identification, chromosomal microarray analysis (CMA), fluorescence in situ hybridization (FISH), sex-determining region Y (SRY) gene detection, and short tandem repeat (STR) microsatellite marker analysis were performed on the peripheral venous blood sample from the proband. Routine semen analysis, sperm FISH, and STR testing were also conducted. STR verification was performed on both parents. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: k20201009). RESULTS: The proband, a 37-year-old male, had normal secondary sexual characteristics and external genitalia development. The chromosomal karyotype of his peripheral blood sample was 46,XX[94]/46,XY[6]. ABO blood group typing was positive for Rh(D) type O and negative for Rh(D) type A, indicating the presence of two red blood cell populations. CMA result was arr[GRCh37](1-22)×2,(XX)×1. Autosomal and X chromosome SNP genotypes were BB-BB, AB-AB, and AA-AA, making it impossible to identify homozygous/heterozygous chimerism. FISH detection of interphase nuclei showed nuc ish XX[92]/XY[8]. Testing of the SRY gene was positive. STR analysis showed a single X peak (no Y peak) at the AMEL locus, 10/12 at the Penta D locus, and no third allele at other loci. Routine semen analysis were normal. Sperm FISH detection showed haploid nuclei nuc ish X[53]/Y[47]. Sperm STR analysis revealed an X/Y bimodal distribution at the AMEL locus and a 9/14 distribution at the Penta D locus, with no third allele observed at other loci. Above results suggested that the proband's blood and germ cell lines had originated from a heterozygous chimera formed by the fusion of two different zygotes. CONCLUSION Combined genetic techniques confirmed that the proband's peripheral blood AMEL genotype is X/X, while the sperm is X/Y. The Penta D locus showed a bi-allelic heterozygous pattern of 10/12 in the peripheral blood sample and 9/14 in the sperm sample, suggesting that the proband is a tetrazygotic chimera resulted from the fusion of 46,XX/46,XY zygotes.
Humans ; Male ; Adult ; Chimerism ; Microsatellite Repeats ; Sex-Determining Region Y Protein/genetics* ; Phenotype ; Genes, sry ; In Situ Hybridization, Fluorescence ; Karyotyping

Background and Objective: Retinoblastoma is one of the most common intraocular cancers among children usually caused by the loss of retinoblastoma protein function. Despite being a highly heritable disease, conventional diagnostic and prognostic methods depend on clinical examination, with limited consideration of cancer genetics in the standard of care. CD133, KRT19, and MUC1 are commonly explored genes for their utility in liquid biopsies of cancer including lung adenocarcinoma. To date, there are few extensive molecular studies on retinoblastoma in Filipino patients. To this end, the study aimed to describe the copy number of CD133, KRT19, and MUC1 in retinoblastoma samples from a Filipino patient and quantitate the respective expression level of these genes. Methods: Hematoxylin & Eosin (H&E) staining was utilized to characterize the retinoblastoma tissue while fluorescence in situ hybridization (FISH) using probes specific to CD133, KRT19, and MUC1 was performed to determine the copy number of genes in retinoblastoma samples from a Filipino patient (n = 1). The gene expression of CD133, MUC1, and KRT19 was quantitated using RT-qPCR. Results: The H&E staining in the retinoblastoma tissue shows poorly differentiated cells with prominent basophilic nuclei. CD133 was approximately 1.5-fold overexpressed in the retinoblastoma tissue with respect to the normal tissue, while MUC1 and KRT19 are only slightly expressed. Multiple intense signals of each probe were localized in the same nuclear areas throughout the retinoblastoma tissue, with high background noise. Conclusion These findings suggest that CD133 is a potential biomarker for the staging and diagnosis of retinoblastoma in Filipino cancer patients. However, further optimization of the hybridization procedures is recommended.
Retinoblastoma ; Biomarkers ; In Situ Hybridization

Objective: To investigate the clinicopathological and cytogenetic features of cryptic COL1A1-PDGFB fusion dermatofibrosarcoma protuberans (CC-DFSP). Methods: Three cases of CC-DFSP diagnosed in West China Hospital, Sichuan University, Chengdu, China from January 2021 to September 2021 were studied. Immunohistochemistry for CD34 and other markers, fluorescence in situ hybridization (FISH) for PDGFB, COL1A1-PDGFB and COL1A1, next-generation sequencing (NGS), reverse-transcriptase polymerase chain reaction (RT-PCR) and Sanger sequencing were performed. Results: There were three cases of CC-DFSP, including two females and one male. The patients were 29, 44 and 32 years old, respectively. The sites were abdominal wall, caruncle and scapula. Microscopically, they were poorly circumscribed. The spindle cells of the tumors infiltrated into the whole dermis or subcutaneous tissues, typically arranging in a storiform pattern. Immunohistochemically, the neoplastic cells exhibited diffuse CD34 expression, but were negative for S-100, SMA, and Myogenin. Loss of H3K27me3 was not observed in the tumor cells. The Ki-67 index was 10%-15%. The 3 cases were all negative for PDGFB rearrangement and COL1A1-PDGFB fusion, whereas showing unbalanced rearrangement for COL1A1. Case 1 showed a COL1A1 (exon 31)-PDGFB (exon 2) fusion using NGS, which was further validated through RT-PCR and Sanger sequencing. All patients underwent extended surgical resection. Except for case 3 with recurrence 2 years after surgical resection, the other 2 cases showed no recurrence or metastasis during the follow-up. Conclusions: FISH has shown its validity for detecting PDGFB rearrangement and COL1A1-PDGFB fusion and widely applied in clinical detection. However, for cases with negative routine FISH screening that were highly suspicious for DFSPs, supplementary NGS or at least COL1A1 break-apart FISH screening could be helpful to identify cryptic COL1A1-PDGFB fusions or other variant fusions.
Female ; Humans ; Male ; Collagen Type I, alpha 1 Chain ; Dermatofibrosarcoma/pathology* ; In Situ Hybridization, Fluorescence ; Oncogene Proteins, Fusion/genetics* ; Proto-Oncogene Proteins c-sis/genetics* ; Skin Neoplasms/pathology* ; Adult

Objective: To investigate the clinicopathological features, immunophenotypes and molecular genetics of EWSR1-SMAD3 positive fibroblastic tumor (ESFT) with an emphasis on differential diagnosis. Methods: The clinicopathological data, immunohistochemical profiles and molecular profiles of 3 ESFT cases diagnosed at the Department of Pathology, Fudan University Shanghai Cancer Center from 2018 to 2021were analyzed. The related literature was also reviewed. Results: There were two males and one female. The patients were 24, 12 and 36 years old, respectively. All three tumors occurred in the subcutis of the foot with the disease duration of 6 months to 2 years. The tumors were presented with a slowly growing mass or nodule, accompanied with pain in 1 patient. The tumors ranged in size from 0.1 to 1.6 cm (mean, 1.0 cm). Microscopically, the tumors were located in the subcutaneous tissue with a nodular or plexiform growth pattern. They were composed of cellular fascicles of bland spindle cells with elongated nuclei and fine chromatin. One of the tumors infiltrated into adjacent adipose tissue. There was no nuclear atypia or mitotic activities. All three tumors showed prominent stromal hyalinization with zonal pattern present in one case. Focal punctate calcification was noted in two cases. The immunohistochemical studies showed that tumor cells were diffusely positive for ERG and negative for CD31 and CD34, with Ki-67 index less than 2%. Fluorescence in situ hybridization on the two tested cases identified EWSR1 gene rearrangement. The next generation sequencing analysis demonstrated EWSR1-SMAD3 fusion in all three cases. During the follow up, one patient developed local recurrence 24 months after the surgery. Conclusions: ESFT is a benign fibroblastic neoplasm and has a predilection for the foot, characterized by ERG immunoreactivity and EWSR1-SMAD3 fusion. Local recurrence might occur when incompletely excised. Familiarity with its clinicopathological features is helpful in distinguishing it from other spindle cell neoplasms that tend to occur at acral sites.
Adult ; Child ; Female ; Humans ; Male ; Biomarkers, Tumor/analysis* ; China ; In Situ Hybridization, Fluorescence ; Neoplasms, Fibrous Tissue/pathology* ; RNA-Binding Protein EWS/genetics* ; Smad3 Protein/genetics* ; Soft Tissue Neoplasms/surgery*