Deletion of (7p13p14) in non-Hodgkin's lymphoma

Deletion of the short arm of chromosome 7 at 7(p13p14) has been occasionally reported in non-Hodgkin's malignant lymphoma (NHL). The inclusion of this abnormality within the list of nonrandom changes awaited further data. We report three partial deletions of 7p with breakpoint at 7p13, found in various subtypes of NHL, and one deletion covering these bands (7p11 to 7p15). The association of 7p- with other chromosomal changes in the same NHL suggests that partial 7p deletion is a nonrandom secondary abnormality.     

Molecular cytogenetic characterization of a subtle interstitial del(3)(p25.3p26.2) in a patient with deletion 3p syndrome

Deletion 3p syndrome is associated with characteristic facial features, growth failure, and mental retardation. Typically, individuals with deletion 3p syndrome have terminal deletions that result in loss of material from 3p25 to 3pter. We present a child with a clinical phenotype consistent with deletion 3p syndrome (ptosis, microcephaly, growth retardation, and developmental delay) and a subtle interstitial deletion in the distal portion of the short arm of chromosome 3, del(3)(p25.3p26.2). Fluorescence in situ hybridization (FISH) studies using 3p subtelomeric probes confirmed the terminal region of chromosome 3 was present. Sequence tagged sites (STS)-linked BAC clones mapping to chromosomal region 3p25-p26 were used to characterize the interstitial deletion by FISH. The results indicate the deletion is within a region of approximately 4.5 Mb between STS markers D3S3630 and D3S1304. This interstitial deletion lies within all previously reported terminal deletions in deletion 3p syndrome individuals, and represents the smallest reported deletion associated with deletion 3p syndrome. Characterization of the deletion may help identify genes important to growth and development that contribute to the deletion 3p syndrome phenotype when present in a hemizygous state.     

Telomere-telomere (end to end) fusion of chromosomes 7 and 22 with an interstitial deletion of chromosome 7p11.2-->p15.1: phenotypic consequences and possible mechanisms

We report a rare case of a de novo end to end fusion of chromosomes 7 and 22 in conjunction with an interstitial deletion of chromosome 7p11.2p15.1 in a newborn with congenital anomalies. The proband presented for chromosome analysis with bilateral cataracts, dysmorphic facies and distal limb abnormalities. Chromosome analysis showed a 45,XY,der(22)psu dic(22;7)(p13;p22.3)del(7)(p11.2p15.1) karyotype. This short arm to short arm fusion of chromosomes 7 and 22 resulted in a pseudodicentric chromosome. The interstitial deletion in the short arm of chromosome 7 was likely a result of breakage and reunion related to instability of the dicentric chromosome. Loss of genetic material in this region of chromosome 7p has been implicated in the pathophysiology of craniosynostosis and cephalopolysyndactyly syndromes.     

De novo terminal deletion 7p22.1--pter in a child without craniosynostosis.

A patient with a de novo terminal deletion of the short arm of chromosome 7 (p22.1--pter) is described. Facial dysmorphism, a congenital heart defect, and genital hypoplasia were evident. There were no signs of craniosynostosis. Our observation confirms that deletion of 7p22 is not necessarily associated with craniosynostosis.     

Chromosome 7p – syndrome: Craniosynostosis with preservation of region 7p2

Deletion of a portion of the short arm of chromosome 7 is associated with a recognizable phenotype which often includes craniosynostosis. Recent reports have suggested that craniosynostosis occurs only if there is a deletion involving band 7p21 or the segment distal to that band. We report on a boy who had an interstitial deletion of7p, not involving band 7p21 or the segment distal to that band, who nevertheless had craniosynostosis. Thus, it appears that the determination of craniosynostosis in this syndrome is more complicated than has been suggested previously.     

Familial interstitial deletion of the short arm of chromosome 4 (p15.33-p16.3) characterized by molecular cytogenetic analysis

This 15-month boy was expressed at the cytogenetic laboratory because of psychomotor development delay. He was tall and had plagiocephaly, micrognathia, high nasal bridge, anteverted nostrils and pectus excavatum. A 46,XY,del(4)(p16.1p16.3) karyotype was found using high-resolution R-banding technique. FISH studies using the LSI Wolf-Hirschhorn dual color 4p16.3 and the TelVysion 4p probes showed no deletion. Using BACs, the distal breakpoint was located in 4p16.3, between RP11-165K4 and RP11-717M10 and the proximal breakpoint in 4p15.33, between RP11-74M11 and RP11-1J7; therefore, approximately 7.96 Mb of the short arm were deleted. The maternal karyotype showed the same deletion, but in a mosaic status. Two distinct phenotypes have been recognized on the basis of the chromosomal bands involved in 4p deletion: the Wolf-Hirschhorn syndrome (WHS) and a proximal 4p deletion syndrome (4p15.2-p15.32). Our observation confirms that the basic WHS phenotype maps distally to this region.     

XY sex reversal and gonadal dysgenesis due to 9p24 monosomy

We describe a case of XY sex reversal, gonadal dysgenesis, and gonadoblastoma in a patient with a deletion of 9p24 due to a familial translocation. The rearranged chromosome 9 was inherited from the father; the patient's karyotype was 46,XY,der(9)t(8;9)(p21;p24)pat. A review shows that 6 additional patients with 46,XY sex reversal associated with monosomy of the distal short arm of chromosome 9 have been observed. The observation that all 7 patients with sex reversal share a deletion of the distal short arm of chromosme 9 is consistent with the hypothesis that the region 9p24 contains a gene or genes necessary for male sex determination. This present case narrows the chromosome interval containing a critical sex determination gene to the relatively small region 9p24. A molecular analysis of this region will provide a means to identify a gene invoved in male sex determination. Am. J. Med. Genet. 73:321–326, 1997. © 1997 Wiley-Liss, Inc.     

7p deletion syndrome: an adult with mild manifestations.

Deletion of 7p results in a wide spectrum of congenital abnormalities and minor facial and hand anomalies, often including craniosynostosis. We report on the oldest recognized patient with this disorder, a 24-year-old woman with an interstitial deletion from p15.3-p21.2 or p21.3. The manifestations in this patient are milder than those of previously described patients, and include borderline mental retardation, short stature, minor facial anomalies, and several skeletal changes. The absence of craniosynostosis in this patient is noteworthy, given previous suggestions that there is a specific locus for this finding in the 7p region. Twelve cases of 7p deletion, in which the missing segment overlaps that of the current case, are reviewed. This case delineates a broader spectrum for patients with 7p deletion syndrome.     

7p Deletion syndrome: An adult with mild manifestations

Deletion of 7p results in a wide spectrum of congenital abnormalities and minor facial and hand anomalies, often including crani-osynostosis. We report on the oldest recognized patient with this disorder, a 24-year-old woman with an interstitial deletion from p15.3-p21.2 or p21.3. The manifestations in this patient are milder than those of previously described patients, and include borderline mental retardation, short stature, minor facial anomalies, and several skeletal changes. The absence of craniosynostosis in this patient is noteworthy, given previous suggestions that there is a specific locus for this finding in the 7p region. Twelve cases of 7p deletion, in which the missing segment overlaps that of the current case, are reviewed. This case delineates a broader spectrum for patients with 7p deletion syndrome. © 1992 Wiley-Liss, Inc.     

Four patients with myelodysplastic syndrome with translocation (1;7)(p11;p11) including one patient with independent clones del(7)q22) [corrected] and t(1;7)(q21;q11)

A translocation involving the short arm of chromosome #1 and the short arm of chromosome #7, [t(1;7)(p11;p11)] was present in four patients with myelodysplastic syndrome (MDS). Two of these patients had prior lymphoproliferative disorders and developed MDS following prolonged therapy with alkylating agents. One of the patients with prior therapy history has two additional independent abnormal clones: one with a partial deletion of the long arm of #7 and the other with t(1;7)(q21;q11). A third patient had a family history of leukemia in both the father and a brother, both of whom developed acute nonlymphocytic leukemia following an MDS phase. The last patient was an elderly woman with no predisposing features.     

Chromosome 7p--syndrome: craniosynostosis with preservation of region 7p2.

Deletion of a portion of the short arm of chromosome 7 is associated with a recognizable phenotype which often includes craniosynostosis. Recent reports have suggested that craniosynostosis occurs only if there is a deletion involving band 7p21 or the segment distal to that band. We report on a boy who had an interstitial deletion of 7p, not involving band 7p21 or the segment distal to that band, who nevertheless had craniosynostosis. Thus, it appears that the determination of craniosynostosis in this syndrome is more complicated than has been suggested previously.     

Localization of a tumor suppressor gene associated with progression of human prostate cancer within a 1.2 Mb region of 8p22-p21.3

Human prostate cancers frequently show loss of heterozygosity at loci on the short arm of chromosome 8. In order to take a step toward isolation of the putative tumor suppressor gene(s) on 8p via positional cloning, we performed high-resolution deletion mapping in 46 prostate cancers (stage B, 20 cases; stage C, 8 cases; endocrine therapy-resistant cancer death, 18 cases) using new 12 restriction fragment length polymorphism markers for this chromosomal region. Allelic losses were observed in 25 of the 44 cases (57%) that were informative with at least one locus. Detailed deletion mapping defined a 1.2 Mb commonly deleted region at 8p22-p2 1.3 flanked by markers cMSR-32 and C18- 105 1. A second region of common deletion was identified between C18-1312 and C18-494 at 8p21-8p11.22, suggesting that at least two tumor suppressor genes associated with prostate cancer are present on chromosome arm 8p. Allelic losses on 8p were observed more frequently in the cancer death cases (14/17, 82%) than in early-stage tumors (11/27, 40%; P < 0.01, Fisher's exact test). In two out of 7 patients for whom DNA was available from metastatic cancers as well as from normal tissues and primary tumors, the primary cancer foci had no detectable abnormality of 8p, but the metastatic tumors showed loss of heterozygosity. These results suggest that inactivation of tumor suppressor genes on 8p plays an important role in the progression of prostate cancer. © 1995 Wiley-Liss, Inc.     

t(1;3)(p36;p21) is a recurring therapy-related translocation

Chromosome bands 1p36 and 3p21 are known to be recurring breakpoints in therapy-related (t-) leukemia. We identified a recurring translocation, t(1;3)(p36;p21), in eight patients with various hematologic malignancies: three patients with ALL, one with chronic myelogenous leukemia (CML) in accelerated phase (AP), two with MDS, and two with AML(M3). Five of the eight patients had a history of chemotherapy, including alkylating agents in three, before the translocation was detected. In two of these five patients, the t(1;3)(p36;p21) emerged only at relapse or in the accelerated phase of CML. The karyotypes of the patients were complex, including -7 and structural abnormalities of 5q, 6q, 7q, 9p, and 11q23. Survival time varied among patients (25 days to more than 16 years). Using FISH with 13 1p35-36 cosmid probes (tel-FB12-CA5-G7-FD2-CB1-ED8-FD9-G32-AE3-G50-AD8-GG4-G43-cen), we delineated the 1p36 breakpoint in two patients with MDS and ALL as lying between FB12 and FD2 (between BAC47P3 and PAC963K15), with a small deletion near the breakpoint in both cases. In the patient with MDS, there was also a deletion at 3p21.3, as detected with the cosmid probe cosNRL9. The results of the present study suggest that t(1;3)(p36;p21) in hematologic diseases is associated with prior exposure to mutagens, including alkylating agents.     

Deletion 7p in gastric MALT lymphoma

Deletion of the long arm of chromosome 7 has been related to loss of tumor suppressor genes which may constitute a primary step of carcinogenesis in many kinds of malignancies, including low-grade B-cell lymphoma. However, deletion of the short arm of chromosome 7, del(7p), in low-grade B-cell lymphoma has not been reported. Here, we report a case of gastric MALT lymphoma with the chromosome aberration del(7p) which progressed in spite of eradication of Helicobactor pylori. Deletion 7p may represent a new karyotypic change that is possibly related to autonomous growth of MALT lymphoma.     

Deletion of 2p: a cytogenetic and clinical update

The locus for acid phosphatase (ACP1) had been alternately assigned to two conflicting regions on the short arm of chromosome 2. We present a clinical and cytogenetic report of one patient who has an interstitial deletion of 2, del(2) (p23p25.1), and a cytogenetic study of another cell line with an interstitial deletion of 2p (p23.1p25.1). Because both patients are heterozygotes for ACP1, the assignment of ACP1 to 2p25.1----pter is supported.     

Ring chromosome 9 [r(9)(p24q34)]: a report of two cases

We report clinical and molecular cytogenetic studies in two patients with ring chromosome 9. Cytogenetics and fluorescent in situ hybridization (FISH) analysis using the p16 gene probe on 9p21, the ABL gene on 9q34, chromosome 9 alpha satellite-centromeric probes, and TelVision 9p and 9q probes which identify subtelomere-specific sequences on chromosome 9p and 9q, revealed 46,XX,r(9)(p24q34).ish r(9)(305J7-T7-,p16+,ABL+, D9S325-) and 46XY,r(9)(p24q34).ish r(9)(305J7-T7-,p16+,ABL+, D9S325-). Based on FISH analysis at least 115 kb was deleted on terminal 9p, and at least 95 kb from terminal 9q. In comparison with other reports of r(9), deletion 9p, and deletion 9q, both patients had clinical characteristics of ring 9 and additional features of deletion 9q or deletion 9p syndrome. The variability between the two cases with r(9) despite similar breakpoints identified by GTG-banding and FISH may be explained by submicroscopic differences between deletion breakpoints, ring instability, interaction of other genes on the phenotype, and variation in fetal environmental conditions.     

Frequent deletion of chromosome 1p sequences in an aggressive histologic subtype of endometrial cancer

The molecular genetic events underlying endometrial tumorigenesis are ill-defined at present. We have identified a region on the short arm of chromosome 1 which is frequently deleted in endometrial cancers. The region of deletion has been localized to bands 1p32-33. Deletion of 1p32-33 is seen more frequently in cancers of the highly aggressive papillary serous type than in cancers of the less-aggressive endometrioid type. These data suggest the presence of a tumor suppressor gene on 1p32-33 which is specifically involved in the development of endometrial cancers with poor outcome.      

Clinical and cytogenetic characterization of 13 Dutch patients with deletion 9p syndrome: Delineation of the critical region for a consensus phenotype

The deletion 9p syndrome is caused by a constitutional monosomy of part of the short arm of chromosome 9. It is clinically characterized by dysmorphic facial features (trigonocephaly, midface hypoplasia, and long philtrum), hypotonia and mental retardation. Deletion 9p is known to be heterogeneous and exhibits variable deletion sizes. The critical region for a consensus phenotype has been reported to be located within a approximately 4-6 Mb interval on 9p22. In the present study, deletion breakpoints were determined in 13 Dutch patients by applying fluorescence in situ hybridization (FISH) and in some specific cases by array-based comparative genomic hybridization (array CGH). No clear genotype-phenotype correlation could be established for various developmental features. However, we were able to narrow down the critical region for deletion 9p syndrome to approximately 300 kb. A functional candidate gene for trigonocephaly, the CER1 gene, appeared to be located just outside this region. Sequence analysis of this gene in nine additional patients with isolated trigonocephaly did not reveal any pathogenic mutations.     

Large de novo deletion of 7p15.1 to 7p12.1 involving the imprinted gene GRB10 associated with a complex phenotype including features of Beckwith Wiedemann syndrome

We present an infant with a de novo cytogenetically visible interstitial deletion of approximately 21.9Mb involving chromosome bands 7p15.1-7p12.1, with the loss of 119 genes confirmed by array CGH. The?infant had a ventricular septal defect, hand and skull anomalies, and hyperglycaemia compatible with haploinsufficiency of TBX20, GLI3, and GCK genes, respectively. In addition, the infant had some features reminiscent of Beckwith Wiedemann syndrome including macroglossia, umbilical hernia, and a relatively large birth weight and we speculate that this is due to the deletion of GRB10, an imprinted gene on chromosome 7. This report illustrates how knowledge of genes within a deleted interval facilitates optimal medical management, can explain observed phenotypes, and stimulates research questions.     

De novo interstitial deletion del(1)(p21p32).

A girl aged 14 years 9 months, overweight, with severe psychomotor retardation, short stature, a sheep-like face, malformed ears, skeletal and dermatoglyphic abnormalities, and partial deletion of the short arm of chromosome 1 is presented. The karyotype was 46,XX,del(1)(qter to p22::p32 to pter).