Allelic loss of selected tumor suppressor genes in acute lymphoblastic leukemia in children.

Defect in function of tumor suppressor genes may lead to initiation/progression of leukemias. RB1, CDKN2A and TP53 gene alterations are found in acute lymphoblastic leukemia (ALL) in children. Data showing a contribution of these alterations to the pathomechanism of leukemias are contradictory and their impact on a disease course still remains undefined. The main aim of the study was to identify and the characterize of RB1, CDKN2A and TP53 allele loss in ALL children patients at diagnosis. 46 children with de novo ALL were examined. Fluorescent in situ hybridization was performed on bone marrow smear preparations. We demonstrated that at least one of three investigated deletions occurred statistically more frequently in T-lineage leukemia patients (p = 0.044); this was the most frequent in respect to RB1 gene (p = 0.054). Additionally, at least one of the examined deletions was observed statistically more frequently in patients with WBC above 20 000/µl (p = 0.043), this was the most frequent for CDKN2A gene (p = 0.066). Presented results seem to give an evidence that deletions of RB1 and CDKN2A genes may contribute to the development of hyperleukocytic type of T-lineage ALL in children, nevertheless this observation needs further investigations.

Another rare case of a child with de novo terminal 9p deletion and co-existing interstitial 9p duplication: clinical findings and molecular cytogenetic study by array-CGH.

Trisomy 9p is the fourth most common chromosome abnormality found in liveborns. We report on a rare case of partial trisomy 9p complicated by partial monosomy 9p. Clinical manifestation included craniofacial abnormalities typical for trisomy 9p syndrome, developmental delay, mental retardation and brain anomaly in the form of Dandy-Walker malformation. The cytogenetic abnormality was investigated with FISH and array-CGH to characterize the breakpoints of the complex rearrangement. The patient's karyotype was 46,XX,der(9)del(9)(p24)dup(9)(p21p24)dn.arr 9p24.3p24.2 (1-2,414,485)×1,9p24.2p21.3(2,414,485-24,101,280)×3. The cytogenetic rearrangement led to a 2.4-Mb deletion of 9p24.2pter and a 21.6-Mb duplication of 9p24.2p21.3. The clinical and cytogenetic findings in our and other similar patients are compared.

Electro-oculogram in patients with neurofibromatosis type 1.

PURPOSE: The electro-oculogram (EOG) is a powerful test to evaluate the functional status of the retinal pigment epithelium (RPE). Clinically detectable changes of the RPE desribed in neurofibromatosis type 1 (NF-1) patients include combined hamartoma of the retina/RPE and congenital hypertrophy of the RPE. The goal of this study was to determine whether the function of RPE as measured by EOG is also changed in individuals with NF-1. PATIENTS: Studies were undertaken in 20 patients with clinically diagnosed NF-1 and compared to 16 normal healthy controls. METHODS: Standard EOG and flash ERG recordings were performed in accordance with International Society for Clinical Electrophysiology of Vision (ISCEV) standards. RESULTS: In NF-1 patients the Arden indexes of the EOG test were significantly higher primarily due to the lower values of dark troughs. Supernormal EOGs were present in 60% of NF-1 patients in comparison to the control group mean +2 SD. No one patient showed so high abnormalities during flash ERG examination. CONCLUSIONS: Dysfunction of the RPE may be characteristic feature of individuals with NF- 1.

Novel RB1 gene constitutional mutations found in Polish patients with familial and/or bilateral retinoblastoma.

Retinoblastoma is the most common intraocular malignancy in children. It is estimated that 60 percent of cases are nonhereditary and unilateral, 15% are hereditary and unilateral, and 25 percent are hereditary and bilateral. Hereditary predisposition for retinoblastoma is caused by germline mutations in the RB1 gene and is transmitted in an autosomal dominant manner. Most of the reported mutations are unique to one family, but there are sites where mutations are recurrent. We have performed RB1 gene mutation analysis in eight patients with familial and/or bilateral retinoblastoma by DNA/RNA sequencing. Constitutional mutations were found in five out of eight patients. Three mutations were novel: g.IVS7+5G>A, g.156709T>A, and g.IVS21+1G>A (p.G203-E240del, p.Y659X, and p.I703-E737del).

The DIRC1 gene at chromosome 2q33 spans a familial RCC-associated t(2;3)(q33;q21) chromosome translocation.

A reciprocal, balanced, constitutional chromosome translocation, t(2;3)(q33;q21), which is associated with familial clear cell renal cancer, has been described and the genomic regions surrounding the 2q and 3q breakpoints have been characterized. Based on the genomic map of the 2q break, EST AI468595 was positioned near the 2q33 translocation and the full-length gene and cDNA were isolated. This 57-kb gene, designated the DIRC1 gene, was disrupted between exons 1 and 2 by the familial translocation. The 1.5-kb mRNA encodes an 11-kDa predicted protein of 104 amino acids. Low-level expression of DIRC1 was detected by reverse transcriptase-polymerase chain reaction amplification in adult placenta, testis, ovary, and prostate and in fetal kidney, spleen, and skeletal muscle. A GFP-Dirc1 fusion protein was expressed in vitro and a polyclonal anti-Dircl peptide serum was prepared. A panel of cancer and cancer-derived cell line DNAs was examined for DIRC1 mutations, but only a rare polymorphism was observed. Two familial tumors showed loss of the derivative 3 chromosome, as observed in a Dutch kindred with t(2;3)associated renal cancers. Mutations in the second DIRC1 allele were not detected. Further studies will be required to determine if disruption of the DIRC1 gene contributed to development of the associated familial clear cell renal cancers.

Characterization of a familial RCC-associated t(2;3)(q33;q21) chromosome translocation.

A Polish family was identified in which multifocal clear cell renal carcinoma segregated with a balanced constitutional chromosome translocation, t(2:3)(q33;q21), similar to the renal cell cancer-associated t(2;3)(q35;q21) reported in a Dutch family. Bacterial artificial chromosome (BAC) contigs encompassing the 2q and 3q breakpoints were constructed and BACs crossing the breakpoints were partially sequenced. All known regional markers, genes, and expressed sequence tags (ESTs) were mapped relative to the contigs, as well as to the breakpoint sequences. Two single ESTs mapped within the 2q breakpoint BAC, whereas the repeat-rich 3q breakpoint region was gene poor. Physical mapping suggested that the 3q break was in 3q13, possibly near the border with 3q21. Physical mapping illustrated that the 2q break was closely telomeric to the 2q31 FRA2G site, consistent with the G-band assignment. Characterization of full-length cDNAs for the ESTs near the 2q break will determine if a gene(s) is altered by this familial translocation.

[Surgical treatment in child gynecology. Germ cell tumors of the ovary in girls]. / Leczenie operacyjne w ginekologii dziewczecej i dzieciecej. Nowotwory germinalne jajnika u dziewczat.

The authors presented 50 girls with germ cell tumours of the ovary. 9/50 (4.5%) were malignant germ-cell tumours. There were 5 patients with pure dysgerminomas, 1 with endotermal simus tumor, 3 with immature teratomas, 3 with gonadoblastoma, 38 with mature teratoma. Kariotype 46XY was present in patients. Authors prefer fertility sparing operative treatment. Primary postoperative therapy in malignant tumors was chemotherapy or radiotherapy. Authors recommend sift out ultrasonographic investigation. Girls should be individually considered for appropriate ovarian surgical procedures. The operative treatment should be as conservative as possible. Absence of follicle apparatus in the gonads require determination of levels of gonadotropin and kariotype.

Frequency and nature of germline Rb-1 gene mutations in a series of patients with sporadic unilateral retinoblastoma.

Constitutional Rb-1 gene mutations were studied in a series of 17 families with isolated unilateral retinoblastoma patients. Peripheral blood lymphocytes were analysed by karyotyping, Southern blot hybridisation, and 'exon by exon' sequencing. Mutations were detected in 4 (24%) of the investigated probands. All mutations were identified by sequencing. No alteration was detected by Southern blotting or karyotyping. In one of our cases with a R358 stop codon mutation, retinoblastoma was unilateral at the time of diagnosis, but a tumour of the second eye was diagnosed after 35 months of follow-up. After exclusion of this case, the frequency of constitutional mutations in our series was 19% (3 of 16 cases). Alterations in our cases without involvement of the second eye included G-->A substitution in the promoter region 198 bp upstream of the initiating methionine codon; G-->C transversion in the splice donor site at position +1 leading to exon 6 skipping and a 137 bp in-frame deletion, starting 3 bp from the 5' end of exon 15 to 27 bp from the 3' end of exon 16. All alterations were germline de novo abnormalities.

Translocation (X;1)(p11.2;q21) in a papillary renal cell carcinoma in a 14-year-old girl.

We report a case of papillary renal cell carcinoma with the karyotype 43-46,X,t(X;1) (p11.2;q21)[5]/80-88,idemx2[5]/45-86,idem,add(5)(p15.1)[2]. This is the second case with such a translocation documented in papillary renal cell carcinoma in a young female.

Age at diagnosis to discriminate those patients for whom constitutional DNA sequencing is appropriate in sporadic unilateral retinoblastoma.

RB1 gene constitutional mutations were studied using 'exon-by-exon' sequencing in a series of 17 patients with sporadic unilateral retinoblastomas. Constitutional de novo germline mutations were detected in 4 patients. The age at diagnosis of retinoblastoma in all these cases was lower (mean 10.8 months; range 5-18) than in cases in which constitutional mutations were not found (mean 31.7 months; range 19-42). These results strongly indicate that age at retinoblastoma diagnosis may be a major factor for discriminating patients for whom a search for RB1 gene constitutional mutations could be justifiable in sporadic unilateral retinoblastomas.

Prevalence and forms of congenital anomalies in twins born in Pomeranian District during the period from 1.07.1997 to 31.12.1998. Polish Register of Congenital Anomalies.

The authors have analysed the frequency and structure of congenital anomalies in children born in the Pomeranian district in the period from 01.07.1997 to 31.12.1998. Among a total of 28.361 births in that area, 748 (2.64%) were affected by congenital anomalies. Among 28.361 births, 620 (2.18%) were from multiple pregnancies. 23 (3.71%) among births from multiple pregnancies were affected by congenital malformations. The prevalence rate of inborn anomalies in births from multiple pregnancy in our area were higher (3.71%) in comparison to births from singleton pregnancy (2.61%). It implies that children born from multiple pregnancy are at higher risk of developing congenital anomalies.

[Clinical examinations in Usher's syndrome]. / Badania kliniczne w zespole Ushera.

In this paper we are showing the results of clinical examinations in the family in which three siblings had the following symptoms: congenital deafness and nyctalopia. Clinical examinations including genetic counseling, audiometry, caloric test, Flash ERG, perimetry, computer tomography revealed total deafness, no vestibular function, and an advanced stage of retinitis pigmentosa. On the basis of clinical results, we determined the correct diagnosis: autosomal recessive Usher's syndrome-type 1. Diagnosis of the syndrome enables qualification of prognosis, complications, possibility of treatment and the risk of having the disease in the next generations. Early identification of the presence of Usher's syndrome can help in the formulation of an appropriate educational and training program. It seems purposeful that all patients with hearing loss should be examined by ophthalmologists.

Chromosome aberrations, spontaneous SCE, and growth kinetics in PHA-stimulated lymphocytes of five cases with Sézary syndrome.

Cytogenetic studies of five patients with Sézary syndrome (SS) revealed clonal chromosome aberrations in all cases. In one patient, a del(8)(p21) was the sole abnormality, whereas the remaining cases had karyotypes with multiple chromosome changes. In three SS cases with hypodiploid chromosome numbers, structural rearrangements affecting regions 10q22-24 and 12p11-13, and aberrations leading to loss of material from 17p were found concurrently. Bands 14q11 and 14q32 were involved in structural rearrangements in one case each. Our results and review of 51 published previously SS cases that were analyzed with banding techniques indicate that the chromosomes most frequently involved in structural changes were chromosomes 1 and 2 (in 43% of cases), 6 (in 38%), 17 (in 34%), 14 (in 27%), 11 (in 25%), 13 (in 21%), and 9 (in 20%). In particular, the breakpoints tended to aggregate at 1p11, 1p36, 2p11-24, 6q, 9q, 11q, 13q11-14, 14q11, 14q32, and in the pericentric region of chromosome 17. The most common numerical change was loss of chromosome 10, detected in 32% of SS cases. In our studies of three SS cases, sister chromatid exchange frequencies were significantly higher in comparison to the normal control. Cell cycle kinetics analysis revealed that the cell cycle time in the malignant cells was significantly longer than in lymphocytes of normal individuals.

[Evaluation of ciliary epithelium cilia in diagnosis of Kartagener syndrome]. / Ocena rzesek nablonka migawkowego w diagnostyce przypadku zespolu Kartagenera.

A case of 41 year man with Kartagener's syndrome presenting incomplete clinical symptoms of disease was described. Diagnosis was established by electron microscopy analysis of nasal mucous membrane cilia biopsy. Ultrastructurally the complete lack of dynein arms was found.

[VNTR-PCR in diagnosis of inherited Rb gene mutation]. / VNTR-PCR w diagnostyce nosicielstwa zmutowanego genu Rb.

Molecular genetic analysis of DNA by PCR-VNTR was performed in a family with hereditary retinoblastoma presenting some difficulties in pedigree analysis. PCR-VNTR allowed to perform a more accurate counselling in this family. Analysis of the way of transmission, carrier status exclusion (in two persons) and confirmation (in one) was possible only by VNTR-PCR.

[RFLP-PCR technique for exclusion of carrier status of the mutated Rb gene]. / Technika RFLP-PCR w wykluczeniu nosicielstwa zmutowanego genu Rb.

Molecular-genetic analysis of DNA by PCR-RFLP technique in a family with a case of unilateral retinoblastoma was performed. The carrier status of mutated Rb gene in a sister of proband was excluded on the basis of molecular analysis despite unsynonymous pedigree data.