无精和严重少精症患者的遗传缺陷分析——-附2例世界首报染色体异常核型

对217例无精和严重少精症患者外周血淋巴细胞染色体核型进行分析,并采用聚合酶链反应对7例Y染色体结构异常患者的AZFc区进行检测。发现187例无精症患者中检出异常核型77例（41.18%）（其中46,XY,t(6;14)(p21;p13),46,XY,t(8;12)(p21;q24)为世界首报核型）,主要涉及染色体异常（数目异常和结构异常）;染色体异态（Y染色体异态和9号染色体臂间倒位）及46,XX性反转;30例严重少精症患者中检出异常核型4例（13.33%）（结构异常和46,XX性反转）。由此可见,性染色体数目和结构异常是精子发生障碍的主要原因,其次常染色体的某些断裂点也可能影响精子发生。AZFc区的缺失与否与精子发生也有直接关系。     

一例12号染色体臂间倒位的细胞遗传学研究

染色体臂间倒位是染色体结构畸变的一种 较为多见的类型。据文献报道,目前人类第1,2, 3, 4, 5, 7, 8, 9, 10, 11、13, 14, 15, 16, 17, 18, 19号染色体以及X与Y染色体均存在臂 间倒位L2,3, 5-7,10,12-147。但12号染色体臂间倒位 尚未见正式报道。现将我室发现的一例核型为 46,XY,inv(12)(p11g13）的患儿的细胞遗 传学研究报道如下。     

25例男性暴力行为精神分裂症患者的染色体分析

本文对25例男性暴力行为精神分裂症病人的外周血淋巴细胞做染色体常规、G带和C带分析。着重测量Y、E组和F组染色体的长度,发现其Y/F平均指数大于1.0(1.014),Y/E平均指数(0.84)也明显高于正常范围(0.75),而且大Y(Y/E指数≥1.0)者占18例(72％),其中15例出现四倍体细胞。这些结果与对照组1(无暴力行为精神分裂症病人24例)和对照组2(正常男性48例)比较,均有显著差异(P<0.001)。据此认为暴力行为精分病人有大Y倾向。但大Y作为暴力行为表达的遗传学基础尚难定论。此外两组49例精分病人中有10例出现9号染色体臂间倒位改变,其频率(20.4％)与1986年洪氏等报道的20.8％频率相仿,再次表明9号臂间倒位很可能作为一种遗传因素参与此病的致病过程。     

25例男性暴力行为精神分裂症患者的染色体分析

本文对25例男性暴力行为精神分裂症病人的外周血淋巴细胞做染色体常规、G带和C带分析。着重测量Y、E组和组染色体的长度,发现其Y/F平均指数大于1.0(1.04),Y/E平均指数(0.84)也明显高于正常范围(0.75),而且大Y(Y/E指数≥1.0)者占18例,其中15例出现四倍体细胞。这些结果与对照组1（无暴力行为精神分裂症病人24例）和对照组2（正常男性48例）比较,均有显著差异(P<0.001)。据此认为暴力行为精分病人有大Y倾向。但大Y作为暴力行为表达的遗传学基础尚难定论。此外两组49例精分病人中有10例出现号染色体臂间倒位改变,其频率(20.4%)与1986年洪氏等报道的20.8%频率相仿,再次表明9号臂间倒位很可能作为一种遗传因素参与此病的致病过程。     

黑龙江地区466例孕妇羊水穿刺产前诊断结果分析

目的:探讨羊水细胞染色体异常核型与各产前诊断之间的关系。方法:466例高危孕妇行羊膜腔穿刺术后羊水细胞培养及染色体核型分析。结果:异常核型66例,异常率14.16%,包括染色体数目异常27例,三体综合征22例(21-三体15例、18-三体6例、13-三体1例),占异常染色体核型的33.33%,占染色体数目异常的81.48%;染色体结构异常39例,主要包括染色体多态性、平衡易位、倒位和衍生等,占染色体异常核型的59.10%。异常核型检出率中血清学筛查高危组(14.44%)要高于高龄妊娠组(10.89%)和有不良孕产史组(11.11%)(P0.05);超声提示胎儿发育异常组(23.26%)要高于血清筛查高危组(P0.05)。结论:血清筛查高危和超声提示胎儿发育异常是黑龙江地区最主要的产前诊断指征,异常核型以21-三体综合征检出率最高。通过对高危孕妇羊水细胞染色体的核型分析可发现部分染色体疾病,从而避免此类出生缺陷儿的出生。     

48例原发性闭经患者的细胞遗传学分析

本文报告对48例原发闭经患者的临床和细胞遣传学分析,共发现染色体异常17例,占35.4%,其中包括45,X,7例;45,X/46,XX,2例;X染色体结构异常5例;核型中有Y染色体3例。讨论了原发闭经的细胞遗传学病因及异常核型与表型的关系。     

孕早期产前诊断46，XX，rec(4)和46，XY,inv(4)和及其家系的细胞遗传学研究

本文报道了用绒毛细胞直接制备染色体的方法，诊断出一个家系中3例染色体异常胎儿。一例核型为：46,XX,rec(4),dup p, inv(4)(P12 q35)另外两例核型为：46, XY, inv(4)(p12 q35)pat。对此家系2代中8人进行了染色体检查。其中3人核型为46, XY, inv(4)(p12q35)。3例胎儿的异常染色体是来自他们的父亲（4号染色体臂间倒位携带者）。并讨论了臂间倒位染色提携带者对后代的影响。     

孕早期产前诊断46,XX,rec(4)和46,XY,inv(4)及其家系的细胞遗传学研究

本文报道了用绒毛细胞直接制备染色体的方法,诊断出一个家系中3例染色体异常胎儿。一例核型为:46,XX,rec(4),dup p,inv(4)(P12 q35)pat;另外两例核型为:46,XY,inv(4)(p12 q35)Pat。对此家系2代中8人进行了染色体检查。其中3人核型为46,XY,inv(4)(P12q35)。3例胎儿的异常染色体是来自他们的父亲(4号染色体臂间倒位携带者)。并讨论了臂间倒位染色体携带者对后代的影响。     

5774例临床生育不良者异常染色体核型分析及32种人类染色体新核型报告

为了探讨异常染色体核型在临床生育不良人群中的分布及其与临床生育结局的关系, 采用常规方法制备外周血淋巴细胞染色体, 经G显带, 对 5 774例临床生育不良者做了外周血染色体核型分析, 检查出异常核型550 例。其中三体核型 255 例占 46.36％, 相互易位 91 例占 16.55％, 染色体倒位 85 例占 15.45％, 染色体缺失 81 例占 14.73％, 罗伯逊易位21例占3.82%, 短臂增加7例占1.27%, 大丫6例占1.09%, 随体异常4例占0.73%。其中 32 例为首次报道的新核型。其临床结局有流产、不育、先天畸形等。结果表明携带异常核型染色体, 可能是影响生育的重要原因之一。     

105种人类染色体新核型的细胞遗传学报道

为了探讨异常染色体的遗传效应, 采用细胞培养、G显带及C显带的方法, 根据人类遗传学国际命名体制(ISCN 2009)对染色体核型命名, 对2009年1月至2012年7月就诊广西壮族自治区妇幼保健院检出的新核型进行细胞遗传学及临床分析。在受检者中检出105种人类染色体新核型, 经检索国内外文献未见报道。其中易位86例, 倒位10例, 衍生染色体6例, 重复染色体1例, 等臂染色体1例, 部分重复和缺失1例。结果显示, 染色体异常是导致流产、不孕不育、先天畸形、智力低下、闭经等疾病的重要原因。     

The clinical significance of pericentric inversion of the human Y chromosome: a rare "third" type of heteromorphism

A 28-year-old normal East Indian was found to have a pericentric inversion of the Y chromosome. After reviewing the literature, it was concluded that an inverted Y chromosome does not impede the production of normal sperm and does not predispose to non-disjunction of other chromosomes in the progeny. Thus, the earlier concept of nondisjunction was rejected, and it is suggested that aberrant cases with aneuploidy and an inverted Y are fortuitous. The pericentric inverted Y is inherited from generation to generation and has no clinical significance. The prevalence of males with pericentric Y inversion in the general population is approximately 1 per 1000. It is suggested that a pericentric inversion of the Y chromosome is a rare chromosomal heteromorphism and should be called type III.     

Replication banding and FISH analysis reveal the origin of the Hyla femoralis karyotype and XY/XX sex chromosomes

The pine woods treefrog, Hyla femoralis, is unique among North American hylid frogs in having a metacentric chromosome 6 and heteromorphic sex chromosomes of the XY/XX type. The X chromosome is distinguished by having a nucleolar organizing region (NOR) in the short arm. The Y chromosome does not possess an NOR. Until the present study, it was not known if the NOR was not present on the Y chromosome or inactive and therefore not detectable by conventional cytogenetic methods like silver staining. Exclusive of its unique features the karyotype of H. femoralis closely resembles those of North American frogs with karyotypes like H. chrysoscelis. We used replication banding and fluorescence in situ hybridization (FISH) with a DNA probe to the 18S + 28S ribosomal genes, which are located at the NOR, to characterize the H. femoralis karyotype. Our analysis revealed that the 18S + 28S ribosomal genes are not present on the Y chromosome, and that the karyotype of H. femoralis was derived from an H. chrysoscelis-like karyotype by relocation of the NOR to the X chromosome from chromosome 6 and either a concurrent or subsequent pericentric inversion of chromosome 6.     

Correlation of the clinical phenotype with a pericentric inversion of chromosome 9]

Pericentric inversion of chromosome 9 is one of the most common structural balanced chromosomal aberrations. It is considered as a paraphysiological variant of a normal karyotype and it is possible to find it as occasional report in healthy subjects. In the last ten years different signals have appeared in literature, concerning carriers of pericentric inversion of chromosome 9, who showed different anomalies of the clinical condition. Today it is difficult, because of the rarity of the data to establish if a true correlation exists between phenotypical anomalies in the subjects studied and the pericentric inversion, or if they are only casual associations. We are trying to find possible correlations between the chromosomal rearrangements and eventual congenital defects. We describe 11 subjects with pericentric inversion of chromosome 9 examined for the presence of dysmorphic signs, mental retardation and repeated miscarriage.     

A new case of partial 14q31.3-qter trisomy due to maternal pericentric inversion

Chromosome 14 is often involved in chromosome rearrangements, although pericentric inversions are rare. Here we report a mother carrying a pericentric inversion of chromosome 14, and her daughter with recombinant chromosome characterized by a partial distal 14q trisomy. Principal clinical findings of the child include facial anomalies, microcephaly, developmental delay, hypotonia and cardiac malformation. Her final karyotype was 46,XX,rec(14)dup(14q)inv(14)(p12q31)mat[20], arr 14q31.3qter(85,427,839–106,356,482)x3. This report brings new data about clinical features of partial 14q trisomy and molecular analysis enables the visualization of genes involved in the segment duplicated.     

Recombinant chromosome 14 due to maternal pericentric inversion

Chromosome 14 is often involved in various chromosome rearrangements, most of them balanced. Human chromosome 14 is acrocentric, so its pericentric inversions are extremely rare (only few cases have been described in the literature). Here we report on a boy with congenital malformations and recombinant chromosome 14 inherited from his mother carrying a pericentric inversion. The proband's G-banded chromosome analysis revealed derivative chromosome 14. Comparative genomic hybridization analysis identified duplication of the terminal part of chromosome 14q ish cgh dup(14)(q32.1qter). This abnormality has been confirmed by custom BAC FISH analysis. His mother's karyotype was 46,XX,inv(14)(p11.2q32.1).     

A recombinant X chromosome in a short statured girl resulting from a maternal pericentric inversion

Summary a 73/4-year-old girl with short stature was found to have a recombinant (X), dup q chromosome resulting from an apparently unique pericentric inversion (X)(p11.2q26) present in her mother and maternal grandmother. The recombinant X chromosome was shown to be late replicating and the inversion X chromosome to be randomly inactivated. This appears to be only the eighth report (7 female, 1 male) of a recombinant resulting from an X pericentric inversion despite all diagnosed females having mild clinical abnormalities. Reasons for the rarity of such recombinant X chromosomes in man are examined.     

Meiotic analysis of a pericentric inversion, inv(7) (p22q32), in the father of a child with a duplication-deletion of chromosome 7

In a family in which a large pericentric inversion of chromosome 7 is segregating, two of the four progeny of inversion heterozygotes show severe psychomotor retardation and have the karyotype 46,XX,rec(7),dup q,inv(7)(p22q32), derived from crossing-over within the inversion. Meiotic analysis in one of the heterozygotes revealed no evidence of inversion loops in well-spread pachytene cells. In approximately 20% of cells in diakinesis, the presumptive bivalent 7 had only one chiasma. Two alternatives to the reversed loop mode of meiotic pairing of inversions are proposed. Review of the literature supports the view that "small" pericentric inversions have a much better genetic prognosis than "large" pericentric inversions.     

Recombinant chromosome as a result of pericentric inversion of X chromosome

Summary A structural X chromosome abnormality was found in the karyotype of a tall patient with gonadal dysgenesis and with no extragenital anomalies. Based on her mother's karyotype, which showed a pericentric inversion of the X chromosome: 46,X,inv(X)(p22q24), as well as from G and R banding, we concluded that the abnormal X chromosome of our patient was a recombinant chromosome that had originated as a result of one crossing over in the inversion loop during gametogenesis in her mother. The recombinant X chromosome had a partial deletion of Xq and a partial duplication of Xp: 46,X,rec(X),dup p,inv(X)(p22q24). After BUDR incorporation, the abnormal X chromosome of the patient and that of her mother showed a late replication. The karyotype-phenotype correlation and the nonrandom inactivation of the inverted X chromosome in the mother are discussed.