9;21相互易位携带者生育多例9p部分三体患者细胞遗传学分析

在河南南阳收集到一个家系4代23人, 其中6人患先天性智力障碍, 具有轻度的面部和小母指畸形等特点, 先证者伴随有癫痫的发生。采用常规的外周血培养染色体G带分析, 发现先证者的核型为：46, XY, der(21) t(9; 21) (9p22.2; 21q22.3)pat, 是部分9p三体。对该家系其他成员的染色体进行分析, 发现所有患者均为部分9p三体, 异常染色体均来自9号与21号染色体平衡易位携带者染色体相互易位的异常分离, 因此这是一个部分9p三体综合征家系。而重复区段发生在9号染色体短臂远端一半区域(9pter→9p21)内, 该区是关键区, 导致智力障碍和面容轻微畸形。     

Trisomy 16q23→qter arising from a maternal t(13;16)(p12;q23): case report and evidence of the reciprocal balanced maternal rearrangement by the Ag-NOR technique

Summary We describe a female new-born with partial trisomy of the long arm of chromosome 16. The chromosome anomaly was the result of an unbalanced segregation of a maternal translocation t(13;16)(p12;q23). Dynamic (RBG, GBG) banding and the Ag-NOR technique ascertained the reciprocal balanced maternal translocation between the 16q23qter and 13q12pter segments because nucleolar organizers were present on the tip of long arms of the derivative 16 maternal chromosome. As monosomy 13p has little or no deleterious effect we consider our case as exhibiting the phenotype of trisomy 16q23qter free from any monosomic feature. Clinical effects are of less consequence as compared with previously published cases of partial trisomy 16q.     

Combined trisomy 9P and Shprintzen syndrome resulting from a paternal t(9;22)

The authors report on a female infant with partial trisomy 9 (pter-->q12) together with partial monosomy 22 (pter-->q11.23) that included DiGeorge critical region (DGCR), as a result of adjacent-2 disjunction. In addition to the clinical features characteristic of trisomy 9p syndrome, the patient had Truncus arteriosus type A2, bilateral hydronephrosis, palatal anomaly, retrognathia, and laryngeal hypotonia, which are likely to be attributed to 22q11.2 deletion. This patient appears to be the first reported case with such unbalanced translocation resulting from a paternal reciprocal translocation. For live birth, the risk for male carrier is 8.7-17.4%. It is important to consider this higher risk when counseling. Precise study concerning the presence of the DGCR can facilitate in the better understanding of the condition.     

Partial trisomy 14q due to maternal t(4;14)(p16;q32) in a dysmorphic newborn

Partial Trisomy 14q is a rare chromosomal disorder that mostly results from a parental translocation. We report here a newborn boy with partial trisomy 14q and dysmorphic features that are compatible with previously reported cases. Conventional cytogenetic analysis revealed an extra chromosomal segment at the end of the short arm of chromosome 4. In order to determine the origin of this chromosome region we used subtelomeric FISH technique. Based on the results of these cytogenetic studies and the physical examination, this dysmorphic case was diagnosed as partial trisomy of 14q and his karyotype determined as 46 XY, der(4)t(4;14)(p16;q32) resulting from a balanced maternal translocation identified as 46,XX, t(4;14)(p16;q32).     

Partial trisomy 17q and monosomy 9p due to a familial translocation.

Described is an infant with partial trisomy 17q and monosomy 9p [46,XX,-9,+der(9)t(9;17)(p21;q23)] due to adjacent-1 segregation of a maternal balanced reciprocal translocation. Characteristic clinical features of both partial 17q trisomy and monosomy 9p are present, but the former syndrome is less recognisable in this infant than in previously reported cases due to the concomitant 9p monosomy.     

Tertiary trisomy of 10p15.pter and 14pter.ql3 due to maternal translocation t(10;14)(p15;q13)

Double partial trisomy resulting from 3:1 segregation of the respective chromosomal segments of the chromosomes involved in a balanced translocation in meiosis is rarely reported in the literature. We present here a first patient with multiple congenital malformations associated with double partial trisomy of 10pter-p15 and 14pter-q13 resulting from 3:1 segregation of maternal balanced translocation t(10;14)(p15;q13). Proximal partial trisomy of chromosome 14 and subterminal trisomy of the short arm of the chromosome 10 are rare. The present case is the first case with double partial trisomy of these segments resulting from 3:1 segregation of a maternal balanced translocation.     

Partial trisomy 16q resulting from maternal translocation 11p/16q

A 3 1/2-year-old male with partial trisomy of the long arm of chromosome 16 resulting from a maternal balanced translocation 11p;16q is described. Clinical findings are compared with similar case reports from the literature.     

Partial trisomy 16q resulting from maternal translocation

Summary A 3 1/2-year-old male with partial trisomy of the long arm of chromosome 16 resulting from a maternal balanced translocation is described. Karyotype: 46,XY,-22,der(22),t(16;22)(q21;p12)mat.     

Trisomy 9p in a girl whose mother has a translocation t(9;20)(q12;p13)

Summary R banding of the fine structure of the chromatids has enabled us to study a new case of trisomy for the short arm of chromosome 9. The syndrome+9p was due to nondisjunction of a maternal translocation t(9;20)(q12;p13).     

Recurrent proximal 18p monosomy and 18q trisomy in a family with a maternal pericentric inversion of chromosome 18

We report a recurrent partial monosomy of 18p10-->11.2 and proximal partial trisomy of 18q10-->21.3 caused by a maternal pericentric inversion of chromosome 18, involving breakpoints p11.2 and q21q21.3 Based on cytogenetics and FISH analysis, we speculate that the recurrent chromosome abnormality in the proband and in the fetus was the result of a translocation, possibly in a germ cell or germ cell precursor, between the maternal normal 18 and her inverted 18, resulting in maternal germinal mosaicism, i.e. 46,XX,inv(18)/46,XX,t[18;inv(18)][q10;q10]. The unbalanced karyotype of the proband and the fetus is 46,XY,+18,der[18;inv(18)][q10;q10]. To the best of our knowledge, there are no reports of this combination of proximal 18p monosomy and proximal 18q trisomy. The other interesting observation was association of Hirschsprung's disease in the proband.     

Partial 4q duplication due to Inherited der(13),t(4;13)(q26;q34)mat in a girl with a deficiency of Factor X

A girl with mental retardation had a partial trisomy 4q. The chromosome aberration originated from a maternal balanced translocation t(4;13)(q26;q34). The value for Factor X was half the normal value, raising the question of the location of a gene related to the production of Factor X on chromosome 4.     

An unusual clinical characterization of a male with distal partial trisomy 1q42.1 and monosomy 4q35.1 and review of the literature

We report a male patient with a karyotype of 46,XY, der(4)t(1;4)(q42.1;q35.1) inherited from a maternal balanced translocation involving chromosome 1q and 4q. The boy had corpus callosum dysgenesis, laryngomalacia, tracheobronchus, facial dysmorphism, simian creases, and developmental retardation. The first three features are unique compared to previous literature reports on distal partial trisomy 1q. This case report allows a further delineation of the distal partial trisomy 1q syndrome.     

Double partial trisomy of 6p23-pter and 9pter-q21.2 in a neonate resulting from 4:2 meiotic segregation of a maternal complex t(6;7;9)(p23;p15;q21.2) translocation

We report, a newborn presenting multiple congenital abnormalities with karyotype; 47,XY,der(7)t(6;7)(pter-p23::p15-->qter),+der(9)t(7;9)(pter-->p15::q21.2--> pter)t(6;7;9)(p23;p15;q21.2)mat[20]. The mother and her phenotypically normal daughter were carriers of a complex chromosomal rearrangement with karyotypes; 46,XX,t(6;7;9)(p23;p15;q21.2)[20]. Paternal chromosomes were normal. In our case the extra derivative chromosome was the result of a 4:2 segregation of the chromosomes involved in translocation during oogenesis. Double partial trisomy in newborns resulting from 4:2 segregation is a rare event, and double partial trisomies of the 6p23-pter and trisomy 9pter-q22 regions have not reported to date.     

Trisomy 9q-. a variant of the 9p trisomy syndrome.

A low-birth-weight near-term male infant was found to have a non-familial 47,XY chromosome complement with an extra medium-sized metacentric chromosome slightly larger than a number 16. By Giemsa-trypsin (G-banding) this extra chromosome was determined to be a number 9 with deletion of approximately half of the long arm at region q 22. Chromosome studies on the clinically normal 38-year-old mother showed a balanced translocation with the deleted portion attached onto the distal end of a number 8 short arm, i.e. 46,XX,t(8;9)(p23;q22). Nondisjunction during meiosis of this woman's normal and deleted number 9 chromosomes is the basis of the child's abnormalities. One half-sibling of the child has a balanced translocation similar to that in the mother. Chromosome analyses on 4 others of the child's maternal half-siblings and on the maternal grandmother all showed normal patterns.     

A severely mental and motor retarded boy with monosomy 9pter-->p22 trisomy 10q26-->qter due to paternal reciprocal translocation 46,XY,t(9;10)(p23;q26)

We report on a twenty-two months old male patient with hypotonia, mental and motor retardation and trigonocephaly. Standard GTG banding chromosomal analysis (from metaphyses of a periferal blood lymphocyte culture) showed 46,XY, der(9) monosomy 9pter-->p22, trisomy 10q26--> qter karyotype. This unbalanced translocation resulted from the father's t(9,10) (p22;p26) karyotype. Deletions of the terminal part of 9p and partial trisomy of chromosome 10q are rare chromosomal disorders. To our knowledge, this is the first case report in the literature of a deletion of 9pter-->p22.3 and a duplication of 10q26-->qter. We assume that the clinical anomalies are due to der(9) monosomy 9pter-->p22, trisomy 10q-->26qter.     

Duplication 11 (q22----qter) in an infant. A case report with review

A male infant with partial duplication of the long arm of chromosome 11 (11q22----qter) is described with a hitherto unreported translocation. In most cases 11q trisomy is associated with 11q/22q translocation and a 3:1 meiotic disjunction with 47 chromosomes. In a few cases the 11q translocation is associated with a partial deletion of other autosomes and a total of 46 chromosomes. In the present case, translocation to 9p is involved and no apparent deletion of 9p was noted, providing an opportunity to delineate the phenotypic features due to duplication of 11q. A comparison is made between the findings of partial 11q trisomy and 11q/22q translocation.     

Familial translocation t(10;21)(q22;q22)

Summary A family is described with a translocation t(10;21)(q22;q22) transmitted through three generations. This family was studied for the apparition of several miscarriages and two sisters with multiple malformations. Both children had a probably partial trisomy of chromosome 10 and a monosomy of chromosome 21 due to a maternal adjacent-2 meiotic segregation.     

A case of insertional translocation resulting in partial trisomy 16p

This report concerns the case of a boy with partial trisomy 16p resulting from the insertional translocation of the short arm of chromosome 16 into the long arm of chromosome 1 in his father. He was referred for genetic testing because of mental retardation, short stature, microcephaly, seizures and multiple dysmorphic features. Chromosome analysis performed in the child demonstrated the presence of additional material in the long arm of chromosome 1. Paternal high resolution chromosome analysis and fluorescence in situ hybridisation revealed the following karyotype: 46,XY,ins(1;16)(q42;p13.1p13.3), while the karyotype of the boy is 46,XY,der(1),ins(1;16)(q42;p13.1p13.3)pat. This is the first reported case of partial trisomy 16p due to paternal insertional translocation.     

Partial and complete trisomy 9: Delineation of a trisomy 9 syndrome

Summary Two infants with trisomy involving chromosome 9 are described. One had complete trisomy 9 and the other karyotype 47,XX,+der(9),t(7;9)(p22;q32)mat. A trisomy 9 syndrome is delineated, consisting of features of the trisomy 9p syndrome and various other malformations. These include abnormalities of the cardiovascular and urogenital systems, cranial suture anomalies, dislocation of the hips and knees and early death. A possible relationship of some of these findings to regions of 9q involved in cases of partial trisomy 9 is suggested.     

Partial trisomy 15q1

Summary A supernumerary extra chromosome of maternal origin, precisely described from QM- and C-banding patterns, was studied in a mentally defective boy with a severe convulsive disorder. This case is considered to represent a specific phenotype of trisomy 15q1. The suggestion that in cases of partial trisomy 15q different phenotypes are due to the second chromosome involved in interchange is supported by the observation of a tertiary trisomy in 2 sibs. It resulted from a balanced reciprocal translocation in the mother t(8q+15q-) and caused an unusual malformation syndrome (mental deficiency, cleft lip and palate, funnel chest, hypospadias).