t(15;21)(q15;q22.1)pat resulting in partial trisomy and partial monosomy of chromosomes 15 and 21 in two offspring

Two sibs, carriers of unbalanced products of the translocation t(15;21)(q15;q22.1)pat, are described. The sister had Prader-Willi syndrome due to deletion 15 (pter > q15) and partial trisomy 21 (pter > q22.1); her brother had partial trisomy 15 (pter > q15) and partial monosomy 21 (pter > q22.1). The translocation breakpoint on chromosome 21 was located proximal to the SOD1 gene, within a region of 4.0 cM (2.3 Mb) between the loci D21S217 and D21S213. The correlations between the clinical presentation and the molecular findings of the two sibs are discussed in relation to other patients with partial trisomy and monosomy 21. © 1996 Wiley-Liss, Inc.     

Recurrent trisomy 15 in a female carrier of der(15)t(Y;15)(q12;p13)

We report on a female carrier of der(15) t(Y;15)(q12;p13) who had two pregnancy losses with trisomy 15 and one with tetraploidy. Molecular analysis showed that both non-disjunction events resulting in the trisomy 15 pregnancies occurred in maternal meiosis I. This finding raises the possibility that there may be an increased risk for trisomy 15 in some carriers of unbalanced t(Y;15) which, if followed by trisomic zygote rescue, may lead to uniparental disomy (UPD).     

Robertsonian (15q;15q) translocation in a child with Angelman syndrome: Evidence of uniparental disomy

A balanced Robertsonian translocation 45,XY,t(15q15q) was detected in a patient with mental retardation, microcephaly, and hypertonia. Deletion of the 15q11q13 region was unlikely based on fluorescence in situ hybridization studies that revealed hybridization of appropriate DNA probes to both arms of the Robertsonian chromosome. Inheritance of alleles from 13 highly polymorphic DNA markers on chromosome 15 showed paternal uniparental isodisomy. The clinical, cytogenetic, and molecular results are consistent with a diagnosis of Angelman syndrome. © 1996 Wiley-Liss, Inc.     

Partial trisomy 16q in two boys resulting from a maternal translocation, t(15;16) (p12;q11)

Two male infants with almost complete trisomy 16q due to a maternal translocation, are reported. The phenotypic similarities of these patients who had trisomy 16q11 leads 16qter and of the eight previously published reports of partial trisomy 16q, were compared.     

Translocation (16;21)(p11;q22) in acute monoblastic leukemia with erythrophagocytosis

A patient with acute monoblastic leukemia with erythrophagocytosis and a t(16;21) (p11;q22), poor response to chemotherapy, early relapse, and a short survival of ten months is presented. Hematologically, this patient could be considered as a case of FAB M5b/t(8;16) but without the characteristic chromosomal translocation, i.e., there is no visible alteration on chromosome 8 and the breakpoint on chromosome 16 appears to be very proximal. These findings are briefly discussed in the light of other variants.     

A rare translocation (4;11)(q21;p14-15) in an acute lymphoblastic leukemia expressing T-cell and myeloid markers.

A 21-year-old male presented with a large mediastinal mass and a white cell count of 420 x 10(9)/L. A diagnosis of acute lymphoblastic leukemia (ALL) was made, with 90% of cells in the bone marrow (BM) and 99% in the peripheral blood (PB) being lymphoblasts (FAB L1). Cytogenetic analysis of these cells revealed a rare variant of the t(4;11) translocation involving chromosome arm 11p rather than 11q, namely t(4;11)(q21;p14-15). The standard form of the (4;11) translocation has been associated with leukemias with mixed-lineage phenotypes. Three cases of ALL with t(4q;11p) have previously been reported. One of these cases showed phenotypic heterogeneity involving myeloid and lymphoid lineages. The leukemia reported here also exhibits lymphoid/myeloid features. Immunophenotyping of the blasts showed that most of the cells were positive for CD2, CD5, CD7, CD10 (CALLA), CD34, and HLA-DR. A significant proportion of the cells expressed CD33. These results suggest a biphenotypic rather than a biclonal disease. Molecular analysis showed rearrangement of both immunoglobulin heavy-chain genes (JH) and of a single allele of the T-cell receptor (TCR) gamma 1 gene, while retaining germline TCR beta genes.     

Subtelomeric monosomy 11q and trisomy 16q in siblings and an unrelated child: molecular characterization of two der(11)t(11;16)

We report here three children with a der(11)t(11;16), two sibs (patients 1 and 2) having inherited a recombinant chromosome from a maternal t(11;16)(q24.3;q23.2) and a third unrelated child with a de novo der(11)t(11;16)(q25;q22.1), leading to partial monosomy 11q and trisomy 16q. Fluorescent in situ hybridization (FISH) using bacterial artificial chromosome (BAC) clones and array‐CGH were performed to determine the breakpoints involved in the familial and the de novo rearrangements. The partial 11 monosomy extended from 11q24.3 to 11qter and measured 6.17–6.21 Mb in Patients 1 and 2 while the size of the partial 11q25‐>qter monosomy was estimated at 1.97–2.11 Mb for Patient 3. The partial 16 trisomy extended from 16q23.2 to 16qter and measured 8.93–8.95 Mb in Patients 1 and 2 while the size of the partial 16q22.1‐>qter trisomy was 20.82 Mb for Patient 3. Intraventricular hemorrhage and transitional thrombocytopenia were found in both sibs but not in the third patient. The FLI1 gene, which is the most relevant gene for thrombocytopenia in Jacobsen syndrome, was neither deleted in family A nor in Patient 3. We suggest that a positional effect could affect the FLI1 expression for these two sibs. Deafness of our three patients confirmed the association of this anomaly to 11q monosomy and tended to confirm the hypothetic role of DFNB20 in Jacobsen syndrome hearing loss. Both sibs shared most of the features commonly observed in Jacobsen syndrome, but not the third patient. This confirmed that terminal 11q trisomy spanning 1 to 1.97–2.11 Mb is not associated with a typical Jacobsen syndrome. © 2011 Wiley‐Liss, Inc.     

Translocation (1;11)(q23;p15), a novel simple variant of translocation (7;11)(p15;p15), in a patient with AML (M2) accompanied by non-Hodgkin lymphoma and gastric cancer

We describe a case of an acute myelogenous leukemia (AML) associated with t(1;11) (q23;p15), which is a novel simple variant translocation of t(7;11)(p15;p15). The patient was a Japanese man who had a history of non-Hodgkin lymphoma (NHL) and received MACOP-B combination chemotherapy. Fifteen months after the completion of the treatment, the patient developed AML (M2), which was regarded as a therapy-related leukemia. Cytogenetic study of bone marrow cells showed t(1;11). Although he achieved complete remission by combination chemotherapy, a relapse of NHL and gastric cancer were revealed in the course of the consolidation chemotherapy for AML. The NHL was considered a histological conversion from follicular lymphoma because lymphoma cells carried t(14;18) (q32;q21) and were strongly positive for BCL2 protein. Translocation (1;11), together with AML having t(7;11) or inv(11) involving 11p15, shows that 11p15 is a common acceptor site of these chromosome aberrations and suggests the significance of the NUP98 gene located in 11p15 in therapy-related leukemia.     

Phenotype of a patient with pure partial trisomy 2p(p23-->pter)

We present the case of a 7-month-old girl with the karyotype 46,XX, der(13) t(2;13)(p23;p11.2).ish der(13)(wcp2+) de novo. Painting confirmed that the additional segment on 13p was of chromosome 2 origin, resulting in trisomy 2p23 -->2pter. The child had a prominent forehead with a flat hemangioma, depressed nasal bridge, protruding tongue, posteriorly angulated ears, esotropia with poor abduction of the right eye, bilateral severe myopia (-5.5 D), retinal hypopigmentation, foveal hypoplasia, and striking left optic nerve hypoplasia. She also had pectus excavatum, a protruding abdomen with diastasis recti, generalized hypotonia, delayed fine and gross motor development, grade II reflux on the left side, and grade III-IV reflux on the right side. An EEG showed epileptiform discharges. Computed tomographic scan of the brain showed decreased white matter, but magnetic resonance imaging showed normal results.     

45,XY,-4,-15,+t(4;15)(p16;p13)-例

患者男,1岁.因先天性发育不良来我院儿科就诊.查体:眼距宽,舌外伸,无通贯掌及掌纹异常,身高、体重均明显低于正常月龄儿童.B超检查显示有先天性心脏病.父亲38岁、母亲35岁生育该患儿,为第2胎.     

Portohepatic shunt in a Down syndrome patient with an interchange trisomy 47,XY,-2,+der(2),+der(21)t(2;21)(p13;q22.1)mat.

A rare vascular portohepatic anomaly was identified in a Down syndrome patient with a 47,XY,-2,+der(2),+der(21)t(2;21)(p13;q22.1) mat chromosomal complement. This vascular defect involves a direct communication between the right portal vein and the inferior vena cava (IVC). We discuss the possibility that this vascular defect is a rare manifestation in Down syndrome. Alternatively, the existence of these 2 rare events in the same patient raises the possibility that they are causally related.     

Two cases of partial trisomy 8p and partial monosomy 21q in a family with a reciprocal translocation (8;21)(p21.1;q22.3).

We report on two mentally retarded adults with an unbalanced karyotype resulting from a familial balanced translocation between chromosomes 8 and 21, t(8;21)(p21.1;q22.3). This translocation has not been reported before. Both patients had partial trisomy 8p and partial monosomy 21q. Fluorescence in situ hybridisation (FISH) was used to determine the chromosomal breakpoints more precisely. The first patient showed mild mental retardation and facial dysmorphism, slightly resembling the earlier described trisomy 8p phenotype. He did not resemble his affected niece, who was more severely retarded, had serious epilepsy, but lacked the facial dysmorphism. Comparing the data of both patients with published reports of trisomy 8p, marked differences were found between patients with an inversion duplication (inv dup) 8p, patients with partial trisomy 8p caused by an unbalanced translocation, and our patients. Inv dup(8p) causes a recognisable phenotype, whereas the phenotype of trisomy 8p resulting from a translocation is much more variable, probably because of the accompanying monosomies. However, even the same abnormal karyotype can cause different phenotypes, as our patients show. Counselling carriers of the balanced translocation in this family, a 20-25% recurrence risk for unbalanced offspring and a 25% risk for miscarriages seem appropriate.     

47,XX,+der(18),t(9;18)(p24;q21) mat: a distinct partial trisomy 18q--syndrome?

A moderately retarded girl had a 47,XX,+der(18),t(9;18)(p24;q21)mat abnormality that was inherited from her mother, who had a 46,XX,t(9;18)(p24;q21) karyotype in most cells, and a minor cell line of 47,XX,+der(18),-t(9;18)(p24;q21). Her dysmorphic features--bilateral epicanthic folds, low-set, abnormal ears, low posterior hairline, clinodactyly of the 5th fingers, and broad great toes--were similar to those of other patients with an additional number 18 chromosome in which all or most of the long arm was missing, thus raising the possibility of a distinct syndrome.