Low-level mosaic trisomy 17 at amniocentesis in a pregnancy associated with a favorable fetal outcome and cytogenetic discrepancy between cultured and uncultured amniocytes

ObjectiveWe present low-level mosaic trisomy 17 at amniocentesis in a pregnancy associated with a favorable fetal outcome and cytogenetic discrepancy between cultured and uncultured amniocytes.Case reportA 32-year-old, primigravid woman underwent amniocentesis at 18 weeks of gestation because of an increased nuchal translucency thickness of 3 mm in the first trimester sonographic screening. Amniocentesis revealed a karyotype of 47,XX,+17 [2]/46,XX [20]. Among 22 colonies of cultured amniocytes, two colonies had a karyotype of 47,XX,+17, whereas the rest 20 colonies had a karyotype of 46,XX. Simultaneous array comparative genomic hybridization (aCGH) on the DNA extracted from uncultured amniocytes revealed arr (1–22,X) × 2 with no genomic imbalance. Prenatal ultrasound and parental karyotypes were normal. Quantitative fluorescence polymerase chain reaction (QF-PCR) analysis on the DNA extracted from the parental bloods and cultured amniocytes excluded uniparental disomy (UPD) 17. The woman was encouraged to continue the pregnancy. A normal 3178-g female baby was delivered at 38 weeks of gestation without any phenotypic abnormalities. The karyotypes of cord blood, umbilical cord and placenta were all 46, XX (40/40 cells). When follow-up at age six months, the neonate was normal in physical and psychosomatic development.ConclusionLow-level mosaic trisomy 17 at amniocentesis can be a transient and benign condition, and can be associated with a favorable fetal outcome and cytogenetic discrepancy between cultured and uncultured amniocytes.     

Mosaic isochromosome 20q at amniocentesis: Prenatal diagnosis,genetic counseling and literature review

ObjectiveWe present prenatal diagnosis of mosaic isochromosome 20q [i(20q)] at amniocentesis, and we review the literature.Case reportA 36-year-old woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XY,i(20)(q10)[27]/46,XY[29]. Prenatal ultrasound findings were unremarkable. The parental karyotypes were normal. Repeat amniocentesis was performed at 20 weeks of gestation. During repeat amniocentesis, array comparative genomic hybridization (aCGH), interphase fluorescence in situ hybridization (FISH) and quantitative fluorescent polymerase chain reaction (QF-PCR) assay were performed on uncultured amniocytes, and conventional cytogenetic analysis, interphase FISH and aCGH were performed on cultured amniocytes. In the repeat amniocentesis, the cultured amniocytes revealed a karyotype of 46,XY. Interphase FISH analysis showed the i(20q) signal in 5.2% (5/96) of the uncultured amniocytes compared with 2% in the control, and in 0.98% (1/102) of the cultured amniocytes compared with 2% in the control. aCGH detected no genomic imbalance in both uncultured and cultured amniocytes. QF-PCR analysis excluded uniparental disomy 20. At 38 weeks of gestation, a healthy 2870-g male baby was delivered with no phenotypic abnormality. The postnatal blood karyotype was 46,XY. FISH analysis on urinary cells showed 2.1% (2/95 cells) mosaicism compared with 1.9% (2/105 cells) in the control.ConclusionMosaic i(20q) at amniocentesis is a benign condition associated with a favorable outcome in most cases and can be a cell culture artifact confined to cultured amniocytes. Molecular cytogenetic analysis using uncultured amniocytes is useful for rapid confirmation. Prenatal diagnosis of very high percentage of mosaicism for i(20q) at amniocentesis should alert the presence of fetal structural abnormalities. Prenatal diagnosis of mosaic i(20q) at amniocentesis should include a detail examination of fetal brain and spine.     

一例成骨不全家系致病变异的鉴定及胚胎植入前遗传学检测

目的:明确一例成骨不全(osteogenesis imperfecta,OI)家系的致病变异并为其提供胚胎植入前遗传学检测(preimplantation genetic testing,PGT)。方法:应用高通量测序结合Sanger测序的方法鉴定患者的候选变异,用直接检测变异的方法对胚胎进行PGT检测,同时筛查囊胚的...     

Sebaceous nevus of Jadassohn: review and clinical-surgical approach

BackgroundNevus sebaceous of Jadassohn is defined as a rare congenital malformation characterized as a non-hereditary hamartoma of the adnexal structures of the skin. Its etiology is not yet well understood, but it is believed to be related to post-zygotic mutations in the HRAS, NRAS and KRAS genes.ObjectiveTo describe the clinical manifestation of nevus sebaceous, as well as the main management techniques addressed in the medical literature. Moreover, the present study discusses a case report of a congenital linear nevus in the left retroauricular region found in a male patient, without extracutaneous manifestations.MethodA narrative review of the literature was carried out.DiscussionNevus sebaceous occurs as lesions with a linear or oval appearance, with a smooth or verrucous texture, generally alopecic and with very variable color. Moreover, nevus sebaceous is one of the components of the so-called linear nevus syndrome or Schimmelpenning-Feuerstein-Mims syndrome, which is associated with multisystemic complications. The treatment of the lesions is still controversial; however, most experts indicate surgical excision as the most frequently adopted treatment method, in addition to multidisciplinary follow-up when the diagnosis of Schimmelpenning-Feuerstein-Mims syndrome is established.ConclusionThe linear nevus syndrome constitutes a rare manifestation; however, its diagnosis should be considered in children born with nevus sebaceous. There is no consensus yet on the best therapy, but surgical removal has shown to be a viable option.     

Healthy live births after mosaic blastocyst transfers with the use of next-generation sequencing

ObjectiveTo determine whether transfer of high-mosaicism (≥50%) embryos can result in healthy newborns.Case reportTwo embryos resulting from controlled ovarian stimulation (COS) in Patient one, 41 years of age (y/o), underwent preimplantation genetic testing for aneuploidy (PGT-A), which demonstrated that one was mosaic (68%) and the other aneuploid; the mosaic embryo was transferred. Amniocentesis at 18 weeks of gestational age (GA) revealed a normal 46, XY karyotype. A phenotypically normal boy was delivered at 39 and 5/7 weeks of GA. For Patient two, 39 (y/o), nine embryos obtained after COS underwent PGT-A, indicating one euploid, four mosaic, and four aneuploid embryos. One euploid and one mosaic (50%) embryo were transferred, resulting in a twin pregnancy. Amniocentesis at 18 weeks of GA showed both fetuses had normal 46, XY karyotypes. Two phenotypically normal boys were delivered at 37 2/7 weeks of GA.ConclusionTransfer of high-mosaicism embryos selected using current techniques can result in healthy euploid newborns. Amniocentesis suggested that mosaic embryos can be self-corrected before 18 weeks of GA.     

原位培养羊水细胞的染色体核型分析

目的探讨不同产前诊断指征孕妇胎儿异常染色体核型发生率和原位培养羊水细胞染色体嵌合体发生率及相关临床意义。方法在超声引导下对14455例具有产前诊断指征的孕妇实施羊膜穿刺抽取羊水进行染色体核型分析,对异常染色体核型进行统计,并对涉及13号、18号、21号或性染色体的嵌合体病例采用荧光原位杂交技术(FISH)进行检测。结果14455例羊水细胞染色体核型中发现异常核型439例,异常核型率为3.0%。包括21-三体194例,18-三体81例,13-三体5例,倒位25例,易位51例,缺失16例,重复13例,性染色体异常54例。嵌合体一共38例,嵌合率为0.26%,其中涉及13号、18号、21号或性染色体的共23例,其核型与FISH结果显示嵌合一致有22例,不一致1例。结论对具有产前指征的孕妇进行羊水细胞染色体核型分析,可以减少染色体病患儿的出生。原位培养羊水细胞可提高染色体嵌合体的诊断,FISH是核型分析的有效补充。     

Recurrent Down's syndrome due to maternal ovarian trisomy 21 mosaicism

A family with three children who had Down's syndrome and one healthy child is reported. Cytogenetic studies of the peripheral blood revealed trisomy 21 in the affected children, and normal karyotypes in both the parents and the healthy child. However, a biopsy of the mother's right ovary showed a mosaic trisomy 21 cell line (8/20 cells). By DNA polymorphism analysis, segregation of trisomy oogonia appeared to be the cause of recurrent trisomy 21. Received: 1 March 1994 / Accepted: 9 May 1994     

Upper limb abnormalities in mosaic trisomy 8 syndrome

Introduction Skeletal abnormalities are known to be a characteristic feature of the trisomy 8 syndrome, and radiological malformations are often more characteristic than the clinical features.Case presentation We report a mentally retarded male known to have mosaic trisomy 8 syndrome who presented with radial deviation of his right wrist. Radiographs showed an open ulna epiphysis with a closed radial epiphysis. Surgery was postponed until an older age as his ulna epiphysis had not yet closed, but clinical correction was achieved with a wrist brace.Conclusion This is the first report of radial deviation of the wrist in a patient with mosaic trisomy 8     

45 XO/49 XYYYY Mosaicism in a male with stigmata of Turner''s syndrome

A male subject with Turner-like stigmata and chromosomic constitution 45,XO (97.5%) and 49,XYYYY (1.1%) is reported. The findings of a low percentage line bearing Y chromosome in a patient with clinical features similar to those described for XO males, would support the hypothesis that masculinization in certain individuals with 45,XO karyotype may be due to an undetected mosaicism.