OBJECTIVE: To explore the clinical phenotype, pregnancy outcome and follow-up of fetuses with 15q11.2BP1-BP2 microdeletions in order to provide a basis for prenatal and reproductive consultation. METHODS: From March 2019 to December 2023, 20 fetuses who were diagnosed with 15q11.2BP1-BP2 microdeletion syndrome at the Prenatal Diagnosis Center of General Hospital of Ningxia Medical University were selected as the study subjects. Results of genetic testing and ultrasound examination, outcome of pregnancy, and postnatal follow-up were retrospectively analyzed. This study has been approved by the Ethics Committee of General Hospital of Ningxia Medical University ([2020]0520B). RESULTS: None of the 20 fetuses was found to have chromosomal abnormality, whilst all were found to harbor a 15q11.2 BP1-BP2 microdeletion by low-depth whole genome sequencing (CNV-seq). The range of deletions was determined as 0.26 ~ 0.87 Mb, and all were rated as pathogenic CNVs. Three fetuses had abnormal ultrasound findings, including 1 with widened renal pelvis, 1 with agenesis of corpus callosum, and 1 with nuchal fold thickening. Parental verification in 10 couples verified that two fetal deletions were de novo, whilst the remaining eight were inherited from a phenotypically normal parent. Following genetic counseling, three couples had opted to terminate the pregnancy, whilst the remaining 17 had continued with the pregnancy until delivery. The 17 liveborns were followed up for 2 months to 5 years, with no obvious abnormality in growth and development noted. CONCLUSION CNV-seq plays an important role in the prenatal diagnosis of 15q11.2 BP1-BP2 microdeletions. Such deletions may not always lead to disease phenotypes. Individualized consultation and long-term follow-up, in combination with intrauterine ultrasound and parental verification are necessary.
Humans ; Female ; Pregnancy ; Chromosomes, Human, Pair 15/genetics* ; Genetic Counseling ; Prenatal Diagnosis ; Chromosome Deletion ; Adult ; Fetus/abnormalities* ; Retrospective Studies ; Pregnancy Outcome ; Ultrasonography, Prenatal ; Genetic Testing ; DiGeorge Syndrome/diagnosis* ; Male

OBJECTIVE: To determine the origin of a mosaicism small supernumerary marker chromosome (sSMC) by cytogenetic and molecular analysis. METHODS: Karyotype analysis, fluorescence in situ hybridization (FISH) and SNP-array were carried out. RESULTS: The karyotype of the patient was mos47,XX,+mar[45]/48,XX,+2mar[3]/46,XX[52]; the SNP-array result was arr[hg19]15q11.1q11.2 (20 161 372-24 314 675)×3, and the repeat fragment was about 4.15 Mb. FISH showed that approximately 50% of the cells have contained a sSMC with double D15Z1 probe site segments derived from abnormal idic(15). This sSMC did not contain SNRPN and PML probe fragments of Prader-Willi syndrome/Angelman syndrome. CONCLUSION When the patient's karyotype and phenotype are inconsistent, cytogenetic and molecular biology technologies should be combined to clarify the karyotype and gene location, so as to provide more accurate genetic consultation for the follow-up treatments.
Chromosome Disorders ; Chromosomes, Human, Pair 15 ; Comparative Genomic Hybridization ; Humans ; In Situ Hybridization, Fluorescence ; Karyotype ; Mosaicism

OBJECTIVE: To explore the genetic basis for three patients with development delay and to correlate their clinical phenotypes with genetic findings. METHODS: The karyotypes of the probands and their parents were analyzed by conventional G-banding. Chromosomal microarray analysis (CMA) was used to detect microdeletion and microduplication. RESULTS: No kartotypic abnormality was detected in the patients and their parents. CMA analysis identified a de novo 3.10 Mb deletion on chromosome 15q24.1q24.2 in case 1, a de novo 3.14 Mb deletion at 15q24.1q24.2 in case 2, and a 3.13 Mb deletion at 15q24.1q24.2 in case 3. All deletions have encompassed the CPLX3,SEMA7A and SIN3A genes. CONCLUSION The three patients were diagnosed with 15q24 microdeletion syndrome. CPLX3,SEMA7A and SIN3A may be the key genes responsible for this syndrome.
Adaptor Proteins, Signal Transducing ; genetics ; Antigens, CD ; genetics ; Child ; Chromosome Deletion ; Chromosome Disorders ; genetics ; Chromosomes, Human, Pair 15 ; genetics ; GPI-Linked Proteins ; genetics ; Humans ; Intellectual Disability ; genetics ; Repressor Proteins ; genetics ; Semaphorins ; genetics

OBJECTIVE: To explore the genetic basis for a fetus featuring growth restriction and validate the effectiveness of a novel noninvasive prenatal testing (NIPT) technique for the detection of chromosomal microdeletions. METHODS: Next-generation sequencing(NGS) and fluorescence in situ hybridization(FISH) were used to analyze the DNA of the fetus. Conventional G-banding was used to analyze the karyotypes of the fetus and its parents. High-throughput sequencing was used to analyze free fetal DNA. RESULTS: NGS analysis has revealed a 4.88 Mb deletion at 15q11.2-q13.1 region in the fetus, which has a 99% overlap with the critical region of Prader-Willi syndrome (Type 2) and Angelman syndrome (Type 2) and encompassed critical genes including SNRPN and UBE3A. NIPT also revealed a 4.6 Mb deletion at 15q12, which was consistent with the results of fetal cord blood and amniotic DNA testing. FISH assay has confirmed the result of NGS. By karyotying, all subjects showed a normal karyotypes at a level of 320~400 bands. CONCLUSION It is quite necessary to carry out genetic testing on fetuses showing growth restriction. NIPT for fetal chromosomal microdeletions/microduplication syndromes is highly accurate for the diagnosis of Prader-Willi/Angelman syndrome.
Angelman Syndrome ; Chromosome Banding ; Chromosomes, Human, Pair 15 ; Female ; Fetus ; Humans ; In Situ Hybridization, Fluorescence ; Prader-Willi Syndrome ; Pregnancy

Objective: To investigate the genetic screening methods for cryptic acute promyelocytic leukemia (APL) to further explore its clinical prognosis. Methods: From June 2016 to November 2018, we collected 373 newly diagnosed APL cases. The patients were retrospected by the results of PML-RARα detections both by RT-PCR and i-FISH, those who harbored positive PML-RARα detection by RT-PCR and negative by i-FISH were chosen. Metaphase FISH and Sanger sequencing were further performed to verify these results. Results: A total of 7 cryptic APL cases were discovered. These cases had tiny fragment of RARα inserted into PML in chromosome 15, formed ins (15;17) . The 7 cryptic APL cases had no PML-RARα gene subtype specificity, involving 5 cases in L subtype, 1 case in S subtype and 1 case in V subtype respectively. After the treatment of retinoic acid and arsenic or anthracyclines, 6 cases achieved complete remission, 1 case died of intracranial hemorrhage on the 6th day of therapy. Conclusion: The size and covering position of PML-RARα probe should be taken into account when PML-RARα was performed by FISH on APL patients. Furthermore, combination with Metaphase FISH could improve the recognition of cryptic APL. There were no differences between the cryptic and common APL patients in terms of clinical features and treatment choices. Cryptic APL patients also had a good response to the therapy of retinoic acid and arsenic or anthracyclines.
Chromosomes, Human, Pair 15 ; Chromosomes, Human, Pair 17 ; Cytogenetics ; Humans ; In Situ Hybridization, Fluorescence ; Leukemia, Promyelocytic, Acute/genetics* ; Oncogene Proteins, Fusion ; Retinoic Acid Receptor alpha ; Tretinoin

OBJECTIVETo report on a case of therapy-related acute monocytic leukemia(t-AML) with t(11;17) (q23;q21)/MLL-AF17q after successful treatment for acute promyelocytic leukemia(APL) with t(15;17) (q22;q21)/PML-RARα.

METHODSA MICM method (bone marrow morphology(M), immunophenotype(I), cytogenetics(C), and molecular biology(M)) was used for the diagnosis and classification of the disease at the time of onset and transformation.

RESULTSThe patient was initially identified with typical morphology and immunophenotype of APL. She has carried t(15;17)(q22;q21) and PML-RARα fusion gene but was without t(11;17)(q23;q21) or MLL gene abnormalities. After 13 months of successful treatment, she has transformed to AML with typical morphology and immunophenotype. t(11;17)(q23;q21) and MLL-AF17q fusion gene were detected in her bone marrow sample, while no PLZF-RARα fusion gene was detected by real-time quantitative reverse-transcription PCR(RQ-PCR) and fluorescence in situ hybridization(FISH).

CONCLUSIONt-AML is a serious complication after successful treatment of APL. t(11;17)(q23;q21) is not specific for the diagnosis of variant APL and can also be detected in t-AML. RQ-PCR and FISH are essential for the diagnosis of such patients.

Chromosomes, Human, Pair 11 ; Chromosomes, Human, Pair 15 ; Chromosomes, Human, Pair 17 ; Female ; Humans ; In Situ Hybridization, Fluorescence ; Leukemia, Monocytic, Acute ; genetics ; Leukemia, Promyelocytic, Acute ; genetics ; Middle Aged ; Neoplasms, Second Primary ; genetics

OBJECTIVETo explore the genetic cause for a child with developmental delay.

METHODSThe karotypes of the child and her parents were analyzed with G-banding analysis. Their genome DNA was analyzed with low-coverage massively parallel copy number variation sequencing (CNV-seq) and verified by single nucleotide polymorphism array (SNP-array).

RESULTSThe karyotype of the child was ascertained as 46,XX,r(15)(p13q26.3), while both parents showed a normal karyotype. CNV-seq and SNP-array have identified a de novo 15q26.2-q26.3 deletion in the child with a size of approximately 3.60 Mb.

CONCLUSIONThe abnormal phenotype of the patient carrying the ring chromosome 15 may be attributed to the presence of the 15q26.2-q26.3 microdeletion. The deletion and haploinsufficiency of the IGF1R gene probably underlie the main clinical features of the patient.

Child, Preschool ; Chromosome Banding ; Chromosomes, Human, Pair 15 ; genetics ; DNA Copy Number Variations ; Female ; Humans ; Karyotyping ; Mosaicism ; Ring Chromosomes ; Sequence Deletion

OBJECTIVETo analyze a case of supernumerary marker chromosome (SMC) with combined genetic techniques and explore its correlation with the clinical phenotype.

METHODSThe SMC was analyzed with G-banded karyotyping, multiplex ligation dependent probe amplification (MLPA), fluorescence in situ hybridization (FISH), and single nucleotide polymorphism array (SNP-array).

RESULTSG-banding analysis indicated that the patient has a karyotype of 47,XX,+mar. MLPA showed that there were duplications of proximal 15q. FISH assay using D15Z4 probes indicated that the SMC was a pseudodicentric chromosome derived from chromosome 15. And SNP-array revealed that there were two extra copies of 15q11-13 region spanning from locus 20 161 372 to 29 071 810.

CONCLUSIONThe duplication of Prader-Willi/Angelman syndrome critical region probably underlies the abnormal phenotype of the inv dup(15) case with a BP3:BP3 rearrangement.

Adult ; Chromosome Banding ; Chromosome Disorders ; genetics ; Chromosomes, Human, Pair 15 ; genetics ; Female ; Gene Rearrangement ; Humans ; In Situ Hybridization, Fluorescence ; Karyotyping

OBJECTIVETo conduct genetic testing and prenatal diagnosis for a pregnant women with growth retardation, severe mental retardation, and a history of adverse pregnancies.

METHODSG-banded chromosome analysis, fluorescence in situ hybridization (FISH), and whole genome DNA microarray were used to analyze the patient and her fetus.

RESULTSThe women was found to be a chimera containing two cell lines with 47 and 46 chromosomes, respectively. Both have involved deletion of 18q21.2q23. FISH analysis suggested that the cell line containing 47 chromosomes has harbored a chromosome marker derived from chromosome 15. The marker has contained chromosome 15p involving the SNRPN locus and part of 15q, which gave rise to a karyotype of 47,XX,del18q21.3,+ish mar D15Z1+ SNRPN+[82]/46,XX,del18q21.3[18]. Whole genome DNA microarray confirmed that a 3.044 Mb fragment from 15q11.2q12 was duplicated, which involved NIPA1, SNRPN and other 17 OMIM genes. Duplication of this region has been characterized by low mental retardation, autism, developmental delay. Meanwhile, there was a 17.992 Mb deletion at 18q21.33q23, which contained 39 OMIM genes including TNFRSF11A and PHLPP1. This fragment was characterized by mental retardation, developmental delay, short stature, and cleft palate. Whole genome microarray analysis confirmed that there was a 17.9 Mb deletion at 18q21.33q23, which has been implemented with mental retardation, general growth retardation, short stature, and cleft palate. After genetic counseling, the family decided to terminate the pregnancy at 21st week.

CONCLUSIONCombined chromosome karyotyping, FISH, and whole genome DNA microarray can determine the origin of marker chromosomes and facilitate delineation of its correlation with the clinical phenotype.

Abortion, Eugenic ; Adult ; Chromosome Aberrations ; Chromosome Banding ; Chromosomes, Human, Pair 15 ; genetics ; Chromosomes, Human, Pair 18 ; genetics ; Fatal Outcome ; Female ; Fetus ; abnormalities ; metabolism ; Growth Disorders ; embryology ; genetics ; Humans ; In Situ Hybridization, Fluorescence ; Intellectual Disability ; embryology ; genetics ; Karyotype ; Karyotyping ; Prenatal Diagnosis ; methods

We report the prenatal diagnosis of an unbalanced translocation between chromosome Y and chromosome 15 in a female fetus. Cytogenetic analysis of parental chromosomes revealed that the mother had a normal 46,XX karyotype, whereas the father exhibited a 46,XY,der(15)t(Y;15) karyotype. We performed cytogenetic analysis of the father's family as a result of the father and confirmed the same karyotype in his mother and brother. Fluorescence in situ hybridization and quantitative fluorescent-polymerase chain reaction analysis identified the breakpoint and demonstrated the absence of the SRY gene in female members. Thus, the proband inherited this translocation from the father and grandmother. This makes the prediction of the fetal phenotype possible through assessing the grandmother. Therefore, we suggest that conventional cytogenetic and molecular cytogenetic methods, in combination with family history, provide informative results for prenatal diagnosis and prenatal genetic counseling.
Chromosomes, Human, Pair 15* ; Cytogenetic Analysis ; Cytogenetics ; Fathers ; Female* ; Fetus* ; Fluorescence ; Genes, sry ; Genetic Counseling ; Grandparents ; Humans ; In Situ Hybridization ; Karyotype ; Mothers ; Parents ; Phenotype ; Prenatal Diagnosis* ; Sex Chromosome Aberrations ; Siblings