Unusual Ph translocations in the French prospective study on chronic myeloid leukemia

In a prospective and collaborative cytogenetic study of chronic myelocytic leukemia (CML) in France, 234 new patients were collected in 3 yr. A standard Ph chromosome was present in 80.7% of the cases; 13.1% of the patients had additional chromosomal abnormalities, and 5.9% of the patients had an unusual Ph translocations (3 simple, 11 complex). Geographical differences in the incidence of the unusual Ph translocations were present.     

伴变异型Ph易位的慢性髓细胞白血病的分子遗传学研究

目的探讨荧光原位杂交（fluorescence in situ hybridization，FISH）及多重荧光原位杂交（multiplex FISH．M-FISH）技术在检测伴变异型Ph易位（variant philadelphia translocation，vPh）的慢性髓细胞自血病（chronic myeloid leukemia，CML）中遗传学改变的意义。方法对10例常规R显带显示伴vPh的CML以双色双融合FISH技术检测其染色体标本。对于间期细胞中仅有单个融合信号的标本，观察其中期细胞，以确定是否为衍生9号染色体[der（9）]缺失。同时对这10例CML进行M—FISH技术检测。结果FISH技术在10例伴vPh的CML中检测到5例存在der（9）缺失。M—FISH检测到除22号染色体外，1、3、5、6、8、10、11和17号染色体也参与vPh，发现了常规细胞遗传学未发现的异常，包括2种未见报道的异常。结论对伴vPh的CML联合使用常规细胞遗传学、FISH、M—FISH技术可使遗传学诊断更加完善。     

Chronic myeloid leukemia with a rare variant Philadelphia translocation: t(9;10;22)(q34;q22;q11)

Cytogenetic studies were conducted on 30 pituitary adenomas, using both direct and/or short-term in vitro culture methods. An apparently normal chromosome complement was found in 14 tumors; 5 adenomas were characterized by hyperdiploid or near-triploid modal chromosome numbers. Recurrent numerical deviations were identified in 12 samples, which primarily involved gains of chromosomes 4, 7, 8, 9, 12, and 20 by gains, and losses of chromosomes 10, 14, 19, and 22. Four adenomas were shown to have structural chromosome rearrangements with no apparent recurrent pattern of involvement.     

Sperm analysis by FISH in a case of t(17; 22) (q11; q12) balanced translocation: case report

Individual sperm from men with balanced translocations have different chromosomal contents. Thus, an estimation of the overall sperm chromosomal imbalance of such patients could help to give the couple an adapted genetic counselling. We report here the study of a balanced translocation carrier, t(17;22) (q11;q12) whose reproductive history reported four miscarriages. Moreover, he had an abnormal semen analysis with oligoteratozoospermia. The meiotic segregation pattern was examined in 700 sperm, using fluorescence in-situ hybridization (FISH). Nineteen percent of the sperm had balanced translocations or were normal. All other sperm were unbalanced (81%) and their distribution was observed as follows: the frequencies of adjacent 1, adjacent 2 and 3:1 segregations were 12.9, 5.8 and 46.8% respectively. Among the segregations scored, 13.7% were related to second meiotic division abnormalities. Less than 2% of the total sperm scored were not explained. The 3:1 segregation was present at a very high rate, which is very unusual. In cases of balanced translocations, we believe that no general features can be drawn. Thus, the FISH technique may be very helpful for genetic counselling, which remains an important step and must be done with care.     

5例伴有t(16;21)(p11;q22)急性白血病的临床和实验研究

目的：报告5例伴有t(16;21)(p11;q22)的急性白血病和其中1例的染色体涂染分析。方法：骨髓细胞24h培养后按常规方法制备染色体，采用R显带技术进行染色体核型分析，并以16号和21号整条染色体涂染探针对其中1例患者进行染色体涂染检测。结果：5例均显示t(16;21)(p11;q22),占15年来进行染色体检查的急性非淋巴细胞白血病患者总数的0．3％（5／1448）。5例均无白血病细胞吞噬其他血细胞现象。1例患者的染色体涂染分析证实了16号和21号染色体之间发生了相互易位。结论：t(16;21)是急性非淋巴细胞白血病中1种少见的非随机的染色体易位，代表了1种独特的白血病亚型。染色体涂染技术是比常规核型分析更为可靠的检测该易位的手段。     

六例伴t(6;9)(p23;q34)急性髓细胞白血病患者的临床和实验研究

目的 探讨伴t(6;9)(p23;q34)急性髓细胞白血病(acute myeloid leukemia,AML)患者的临床和生物学特点.方法 抽取骨髓细胞按常规制备染色体标本,采用R显带技术进行核型分析;采用标准流式细胞仪和一组单抗检测白血病细胞的抗原表达;应用6号与9号全染色体涂染探针进行染色体荧光原位杂交(fluorescence in situ hybridization,FISH)分析;应用逆转录-PCR技术进行DEK/CAN融合基因和FLT3-ITD突变的检测.结果 t(6;9)易位主要见于M2和M4(M2 4例,M4 2例).所有病例的原始细胞均高表达CD13、CD33,其中4例同时表达HLA-DR、3例同时表达CD34和CD117,1例同时表达CD38,1例同时表达CD15.涂染证实6例患者均涉及6和9号染色体的易位,逆转录-PCR检测显示6例患者的DEK/CAN融合基因均为阳性,其中3例同时存在FLT-ITD突变,6例中的3例经治疗后死亡,生存期分别为3、5和6个月,其余病例仍在缓解中.结论 t(6;9)(p23;q34)为AML少见的再现性异常,伴有t(6;9)(p23;q34)易位的AML具有独特的生物学特征和临床特点,预后大多不良.     

Chronic myeloid leukemia with unusual variant Ph translocation (22;22)(q11;q13). Two cases with chimeric BCR-ABL transcripts

We studied two cases of chronic myelogenous leukemia (CML) with unusual variant Philadelphia (Ph) translocation (22;22)(q11;q13). Southern blot analysis showed a chromosomal break in the BCR gene within the 5.8-kilobase (kb) breakpoint cluster region (bcr), between bcr exons 2 and 3 and between bcr exons 3 and 4, respectively. Chimeric bcr-abl mRNA was detected using polymerase chain reaction (PCR) which amplified, according to the respective bcr breakpoints, bcr exon 2-abl exon II and bcr exon 3-abl exon II junction products. These results further support the involvement, even when not cytogenetically detectable, of the 9q34 chromosomal region in all variant Ph translocations and that BCR-ABL gene fusion products are causally involved in the development of Ph positive CML.     

Duplication 8q syndrome due to familial chromosome ins(10;8)(q21;q212q22)

We describe a kindred in which an ins(10;8)(q21;q212q22) chromosome rearrangement has been segregating for at least four generations. The risk for balanced carriers to have offspring with duplication of 8q212→8q22 is about 0.31. Individuals with unbalanced chromosomes are mildly to moderately mentally retarded and have a similar unusual appearance. Other manifestations include highly arched or cleft palate (8/9), micrognathia (6/9), sloped shoulders (4–6/9), convulsions (4/9), camptodactyly (3/9), pectus excavatum (2/9), elbow contractures (1/9), and postaxial polydactyly (1/9). The appearance and habitus resemble the mosaic trisomy 8 syndrome, although other anomalies of mosaic trisomy 8, such as vertebral, patellar, and renal defects, were not demonstrated.     

Familial t(11;13)(q21;q14) and the duplication 11q, 13q phenotype

Cases of duplication of distal 11q or proximal 13q have been reported independently. A specific translocation resulting in duplication of distal 11q, [der(22)t(11;22)(q23;q11)], has been documented in over 40 cases. We report on a male fetus with chromosomal excess of both distal 11q and proximal 13q resulting from a familial translocation. This case supports the causal association of duplication 11q with neural tube defects. © 1993 Wiley-Liss, Inc.     

Pediatric acute myeloid leukemia with t(7;21)(p22;q22)

The t(7;21)(p22;q22) resulting in RUNX1‐USP42 fusion, is a rare but recurrent cytogenetic abnormality associated with acute myeloid leukemia (AML) and myelodysplastic syndromes. The prognostic significance of this translocation has not been well established due to the limited number of patients. Herein, we report three pediatric AML patients with t(7;21)(p22;q22). All three patients presented with pancytopenia or leukopenia at diagnosis, accompanied by abnormal immunophenotypic expression of CD7 and CD56 on leukemic blasts. One patient had t(7;21)(p22;q22) as the sole abnormality, whereas the other two patients had additional numerical and structural aberrations including loss of 5q material. Fluorescence in situ hybridization analysis on interphase cells or sequential examination of metaphases showed the RUNX1 rearrangement and confirmed translocation 7;21. Genomic SNP microarray analysis, performed on DNA extracted from the bone marrow from the patient with isolated t(7;21)(p22;q22), showed a 32.2 Mb copy neutral loss of heterozygosity (cnLOH) within the short arm of chromosome 11. After 2‐4 cycles of chemotherapy, all three patients underwent allogeneic hematopoietic stem cell transplantation (HSCT). One patient died due to complications related to viral reactivation and graft‐versus‐host disease. The other two patients achieved complete remission after HSCT. Our data displayed the accompanying cytogenetic abnormalities including del(5q) and cnLOH of 11p, the frequent pathological features shared with other reported cases, and clinical outcome in pediatric AML patients with t(7;21)(p22;q22). The heterogeneity in AML harboring similar cytogenetic alterations may be attributed to additional uncovered genetic lesions.     

Double chromosome anomaly: Interstitial deletion 5q and reciprocal translocation (1;11) (p22;q21)

We describe a girl with multiple congenital abnormalities and developmental delay; her karyotype showed an apparently balanced translocation between the short arm of chromosome 1 and the long arm of chromosome 11, and an interstitial deletion of the long arm of chromosome 5 (q15q31). The clinical findings are compared with those described in other cases of 5q deletion, and the origin of the chromosome rearrangements is briefly discussed.     

Analysis of human sperm chromosome complements from a male heterozygous for a reciprocal translocation t(11;22)(q23;q11)

A reciprocal translocation between chromosomes 11 and 22 (t(11;22)(q23;q11)) is a site-specific translocation that is of particular interest because of the propensity for 3:1 segregation of the chromosomes during meiosis. There have been no published reports of chromosomally unbalanced offspring born as a result of adjacent 1 or 2 meiotic segregations in a heterozygote for this translocation. This could be explained by a meiotic mechanism which produces only 3:1 chromosomal segregations or by differential embryonic survival in which 2:2 adjacent segregations do not produce a viable pregnancy. To distinguish between these two possibilities, sperm chromosome complements from a man heterozygous for this 11;22 translocation were studied. The human sperm chromosomes were analysed after fertilization of zona pellucida-free golden hamster eggs. All possible 2:2 (alternate, adjacent 1, adjacent 2) and 3:1 segregations were observed and these segregations occurred in approximately equal frequencies. The frequency of other chromosome abnormalities, unrelated to the translocation, did not appear to be increased. These results indicate that the 11;22 translocation does not specifically cause 3:1 disjunction of chromosomes but that this segregation of chromosomes is more likely to result in a viable pregnancy.     

Melkersson-Rosenthal syndrome and de novo autosomal t(9;21)(p11;p11) translocation

In this report we describe a 26-year-old female with the typical clinical symptoms and signs of Melkersson-Rosenthal syndrome, an autosomal dominant disorder with variable expression, and a de novo t(9;21)(p11;p11), and suggest that the "Melkersson-Rosenthal gene" is located at 9p11.     

Segregation analysis of a translocation (16;21)(p11;q22) in a large pedigree

A large family with an inherited reciprocal translocation (16;21) is described. An unbalanced karyotype due to adjacent-1 segregation was documented in 6 cases, whereas 25 children dying within the first year of life and 4 individuals dying at later ages probably had the same abnormality. Therefore minimal and maximal risk estimates were calculated to be 6.0% and 26.5% for female, respectively, 4.8% and 33.3% for male translocation heterozygotes. Among the karyotyped phenotypically normal offspring of male as well as female carriers the ratio of normal children to balanced carriers was not different from 1:1.     

Translocation X;9(q24;q34) in a girl with ovary dysfunction

A balanced de novo translocation X;9(q24;q34) was discovered in a 21-year-old girl with oligomenorrhoea. The structurally normal X was late replicating in all cells. The results indicate that an X chromosome breakpoint at q24 provokes ovary dysfunction.