[Familial presentation of microdeletion and inverted microduplication with array-CGH]. / Microdelecion y microduplicacion inversa de presentacion familiar con array-CGH.

INTRODUCTION. Over the years the field of genetics has advanced significantly. Following the polymerase chain reaction and mass sequencing techniques, the array-CGH technique (comparative genomic hybridization) has helped to improve genetic procedures. A resolution of up to 200 kb is currently being accomplished in the human genome. CASE REPORTS. We report the case of two sisters with delays in developmental milestones and a characteristic phenotype with normal results from initial studies of the karyotype and subtelomeric regions. Array-CGH was later used to detect a deletion and duplication that were different in each of the sisters, this being the result of a balanced paternal translocation. In the two cases, despite being the result of the same translocation, the genetic and phenotype expression were different. CONCLUSIONS. The precision achieved by means of array-CGH is making it possible to establish a correlation between minimum gains or losses of the genome and the clinical features. Chromosome 3 codes for genes that play a fundamental role in neurological development (contactins, neurotransmitter modulator proteins, etc.) and chromosome 10 codes for proteins involved in apoptosis and proteins regulating transcription. In the literature there have been reports of chromosome 3 deletion syndrome and monosomy 10. Likewise, there are also descriptions of rearrangements between these chromosomes in individuals from the same family. Nevertheless, we describe two cases of a family with a micro-deletion and an inverted microduplication, detected by means of array-CGH, that have not been reported to date. This technique can provide a diagnostic and prognostic approximation as regards development and offer genetic counselling.

TITLE: Microdelecion y microduplicacion inversa de presentacion familiar con array-CGH.Introduccion. A lo largo de los años se han logrado avances en torno a la genetica; tras la reaccion en cadena de la polimerasa y las tecnicas de secuenciacion masiva, la tecnica array-CGH (comparative genomic hybridization) ha contribuido a mejorar los procedimientos geneticos. Actualmente esta consiguiendo una resolucion de hasta 200 kb en el genoma humano. Casos clinicos. Se presentan dos hermanas con retraso en los hitos del desarrollo y fenotipo caracteristico con estudio inicial de cariotipo y de regiones subtelomericas normales. Posteriormente, mediante array-CGH se detecto en cada una una delecion y una duplicacion diferentes, fruto de una translocacion equilibrada paterna. En ambas, siendo fruto de una misma translocacion, muestra diferente expresion genetica y fenotipica. Conclusiones. La precision conseguida mediante el array-CGH esta permitiendo correlacionar minimas ganancias o perdidas del genoma con la clinica. En el cromosoma 3 se encuentran codificados genes fundamentales en el desarrollo neurologico (contactinas, proteinas moduladoras de neurotransmisores…), y en el cromosoma 10, proteinas implicadas en la apoptosis y proteinas reguladoras de la transcripcion. En la bibliografia se han descrito el sindrome de delecion del cromosoma 3 y la monosomia 10. Igualmente, hay descritos reordenamientos entre estos cromosomas en individuos de una misma familia. Sin embargo, aportamos dos casos de una familia con una microdelecion y una microduplicacion inversa, detectados mediante array-CGH, no descritos hasta el momento. Dicha tecnica puede ofrecer una aproximacion diagnostica y pronostica en cuanto a la evolucion y ofertar consejo genetico.

Relatives with opposite chromosome constitutions, rec(10)dup(10p)inv(10)(p15.1q26.12) and rec(10)dup(10q)inv(10)(p15.1q26.12), due to a familial pericentric inversion.

Large pericentric inversions in chromosome 10 are rare chromosomal aberrations with only few cases of familial inheritance. Such chromosomal rearrangements may lead to production of unbalanced gametes. As a result of a recombination event in the inversion loop, 2 recombinants with duplicated and deficient chromosome segments, including the regions distal to the inversion, may be produced. We report on 2 relatives in a family with opposite terminal chromosomal rearrangements of chromosome 10, i.e. rec(10)dup(10p)inv(10) and rec(10)dup(10q)inv(10), due to familial pericentric inversion inv(10)(p15.1q26.12). Based on array-CGH results, we characterized the exact genomic regions involved and compared the clinical features of both patients with previous reports on similar pericentric inversions and regional differences within 10p and 10q. The fact that both products of recombination are viable indicates a potentially high recurrence risk of unbalanced offspring. This report of unbalanced rearrangements in chromosome 10 in 2 generations confirms the importance of screening for terminal imbalances in patients with idiopathic intellectual disability by molecular cytogenetic techniques such as FISH, MLPA or microarrays. It also underlines the necessity for FISH to define structural characteristics of such cryptic intrachromosomal rearrangements and the underlying cytogenetic mechanisms.

A new der(1;7)(q10;p10) leading to a singular 1p loss in a case of glioblastoma with oligodendroglioma component.

The combined 1p-/19q- deletions in oligodendrogliomas originate from translocation between both chromosomes. In the few cases of oligoastrocytomas and glioblastomas with an oligodendroglioma component (GBMO) where only 1p deletion was described, the origin remains unknown. We report the first case of GBMO, in which a single 1p deletion was detected and was linked to a translocation between chromosomes 1 and 7. Fresh surgical specimens were collected during surgery and the samples were used for cell culture, touch preparation smear slides (TP slides) and DNA extraction. Peripheral venous blood was also collected from the patient. G-banding using Trypsin and stained with Giemsa (GTG) banding and karyotyping were performed and 1p-/19q-, TP53, PTEN and c-MYC were analyzed by fluorescent in situ hybridization (FISH). Multicolor FISH (mFISH) and microsatellites analyses were also performed to complete the investigation. Three-dimensional quantitative FISH (3D-QFISH) of telomeres was performed on nuclei from TP slides and analyzed using TeloView(TM) to determine whether the 3D telomere profile as an assessment of telomere dysfunction and a characterization of genomic instability could predict the disease aggressiveness. An unbalanced chromosomal translocation was found in all metaphases and confirmed by mFISH. The karyotype of the case is: 50∼99,XXX, +der(1;7)(q10;p10),inc[47] The derivative chromosome was found in all 47 analyzed cells, but the number of derivatives varied from one to four. There was neither imbalance in copy number for genes TP53 and PTEN, nor amplification of c-MYC gene. We did not find loss of heterozygosity with analysis of microsatellite markers for chromosomes 1p and 19q in tumor cells. The 3D-telomere profile predicted a very poor prognostic and short-term survival of the patient and highlights the potential clinical power of telomere signatures as a solid biomarker of GBMO. Furthermore, this translocation between chromosomes 1 and 7 led to a singular 1p deletion in this GBMO and may generate the 1p and 7q deletions.

Comprehensive analysis of PTEN status in Sezary syndrome.

Sézary syndrome (SS) is an incurable leukemic variant of cutaneous T-cell lymphoma characterized by recurrent chromosomal alterations, among which, chromosome 10q deletion is very frequent. In this study, we investigated the PTEN status, on locus 10q23, in 44 SS patients; our findings show that PTEN is deleted in 36% of SS cases, whereas PTEN downregulation is observed in almost all of the samples evaluated by quantitative reverse-transcriptase polymerase chain reaction and Western blotting analysis. Neither DNA sequence mutation nor promoter hypermethylation were found at the PTEN locus, but we demonstrate that PTEN level can be also reduced by a group of miRs previously found upregulated and of prognostic relevance in SS; particularly, miR-21, miR-106b, and miR-486 were able to control PTEN abundance either in vitro or in vivo. Finally, because reduced PTEN activates the PI3/AKT-mediated pathway of cell growth and survival, we demonstrate that PTEN deficiency is associated with activated AKT in skin resident but not circulating SS cells, suggesting that the cutaneous milieu may strongly contribute to the SS cell growth. To our knowledge, this is the first study fully exploring the PTEN status in a large cohort of SS patients, unveiling potential elements of clinical utility in this malignancy.

Unbalanced jumping translocation involving 3q in myeloproliferative disease.

An 87-year-old woman was diagnosed with unclassified myeloproliferative disease having an acquired jumping translocation with the long arm of chromosome 3 translocating to the short arm telomeric region of chromosome 8 (major clone) and the long arm telomeric region of chromosome 10 (minor clone). Each abnormal clone was also associated with an extra copy of chromosome 8. Although there was no evidence of transformation to an acute leukemia, the patient deteriorated until her demise 7 months after disease presentation. There have been fewer than 70 cases of acquired jumping translocations reported in the literature. To our knowledge, this is the first acquired jumping translocation case to be reported in a patient with myeloproliferative disease.

ETV6/GOT1 fusion in a case of t(10;12)(q24;p13)-positive myelodysplastic syndrome.

The ETV6/GOT1 fusion, resulting from t(10;12) (q24;p13), has been recently described in a myelodysplastic syndrome. We reported a second case of t(10;12)-positive myelodysplastic syndrome in whom fluorescent in situ hybridization confirmed the non-random translocation but molecular biology analyses revealed a ETV6/GOT1 chimera varying from the first case described.

Decreased catalytic activity of the insulin-degrading enzyme in chromosome 10-linked Alzheimer disease families.

Insulin-degrading enzyme (IDE) is a zinc metalloprotease that degrades the amyloid beta-peptide, the key component of Alzheimer disease (AD)-associated senile plaques. We have previously reported evidence for genetic linkage and association of AD on chromosome 10q23-24 in the region harboring the IDE gene. Here we have presented the first functional assessment of IDE in AD families showing the strongest evidence of the genetic linkage. We have examined the catalytic activity and expression of IDE in lymphoblast samples from 12 affected and unaffected members of three chromosome 10-linked AD pedigrees in the National Institute of Mental Health AD Genetics Initiative family sample. We have shown that the catalytic activity of cytosolic IDE to degrade insulin is reduced in affected versus unaffected subjects of these families. Further, we have shown the decrease in activity is not due to reduced IDE expression, suggesting the possible defects in IDE function in these AD families. In attempts to find potential mutations in the IDE gene in these families, we have found no coding region substitutions or alterations in splicing of the canonical exons and exon 15b of IDE. We have also found that total IDE mRNA levels are not significantly different in sporadic AD versus age-matched control brains. Collectively, our data suggest that the genetic linkage of AD in this set of chromosome 10-linked AD families may be the result of systemic defects in IDE activity in the absence of altered IDE expression, further supporting a role for IDE in AD pathogenesis.

Genetic alterations in chromosome 10q24.3 and glutathione S-transferase omega 2 gene polymorphism in ovarian cancer.

The molecular basis of ovarian cancer development has not been fully elucidated. In this study, genetic alterations in ovarian cancer were identified by arbitrarily primed polymerase chain reaction (AP-PCR). A gene in DNA fingerprinting, amplified from primer AE11, was cloned, sequenced, and identified by comparison with known genes in the genome database. Gene amplification in chromosome 10q24.3 was identified and measured by real-time PCR. Three out of 20 cases harbored this gene amplification. This amplified region was identified as IVS-4 of the glutathione-S-transferase Omega 2 (GSTO2) gene. Therefore, the mutations in all 6 exons of the GSTO2 gene were determined. The A to G transition at codon 142 in exon 4 (AAT to GAT, N142D) was observed. The frequency of GSTO2 gene polymorphism was analyzed in 20 ovarian cancers, compared with 41 normal individuals. The gene frequencies of D142 and N142 allele in ovarian cancer cases were 0.3 and 0.7, whereas in normal females, they were 0.2 and 0.8, respectively. The odds ratio of D142 allele in ovarian cancer was 1.73 (95% CI = 0.51-5.89), indicating that this GSTO2 gene polymorphism may be associated with the risk of ovarian cancer.

A metachronous, atypical, multifocal renal oncocytoma with a concomitant renal cell carcinoma of the contralateral side and bilateral multifocal oncocytomas: two case reports and review of literature.

We present one case of a metachronous, atypical, multifocal renal oncocytoma with a concomitant chromophobe renal cell carcinoma (RCC) of the contralateral side and one case of bilateral and multifocal oncocytomas. Oncocytomas are benign renal tumours that rarely appear bilateral or multifocal or with coexisting RCC. A common pathogenic denominator of oncoytomas and RCC is being discussed. The first case was a 63 years old patient presenting with a history of nephrectomy for a pT1 G1 pN0 R0 papillary RCC 4 years prior to presentation, showed two tumours of a singular kidney. Upon nephron-sparing surgery one typical and one atypical oncocytoma with an invasion of the perinephric fat were found. Comparative genomic hybridisation was performed. Both tumours revealed genetic alterations with loss of genetic material on chromosome 1p. The second case was a 62 years old patient presenting with multifocal and bilateral renal tumours of undeclared dignity upon imaging. During open exploration all tumours could be removed by nephron-sparing surgery and were identified as oncocytomas. Again comparative genomic hybridisation was performed. All 4 tumours revealed genetic alterations with loss of genetic material on chromosome 1p, one of the tumours an additional loss of chromosome 10.

Lack of response to imatinib mesylate in a patient with accelerated phase myeloproliferative disorder with rearrangement of the platelet-derived growth factor receptor beta-gene.

Imatinib mesylate has been reported to produce positive results in atypical chronic myeloproliferative disorders (CMD) with chromosomal translocations that disrupt the platelet-derived growth factor receptor beta gene (PDGFRB). We used imatinib to treat a 49-year old man with atypical CMD in accelerated phase and the H4 (D10S170)-PDGFRB fusion gene. After 3 months of treatment, we observed grade 4 hematologic toxicity and a lack of response.

Chromosome 10p deletion in a patient with hypoparathyroidism, severe mental retardation, autism and basal ganglia calcifications.

Chromosome 10p terminal deletions have been associated with a DiGeorge like phenotype. Haploinsufficiency of the region 10p14-pter, results in hypoparathyroidism, sensorineural deafness, renal anomaly, that is the triad that features the HDR syndrome. Van Esch (2000) identified in a HDR patient, within a 200 kb critical region, the GATA3 gene, a transcription factor involved in the embryonic development of the parathyroids, auditory system and kidneys. We describe a new male patient, 33-year-old, with 10p partial deletion affected by hypocalcemia, basal ganglia calcifications and a severe autistic syndrome associated with mental retardation. Neurologically he presented severe impairment of language, hypotonia, clumsiness and a postural dystonic attitude. A peripheral involvement of auditory pathways was documented by auditory evoked potentials alterations. CT scan documented basal ganglia calcifications. Hyperintensity of the lentiform nuclei was evident at the MRI examination. Renal ultrasound scan was normal. Haploinsufficiency for GATA3 gene was documented with FISH analysis using cosmid clone 1.2. Phenotypic spectrum observed in del (10p) is more severe than the classical DGS spectrum. GATA3 has been found to regulate the development of serotoninergic neurons. A serotoninergic dysfunction may be linked with autism in this patient.

FSHD in Chinese population: characteristics of translocation and genotype-phenotype correlation.

Current studies of facioscapulohumeral muscular dystrophy (FSHD) are confined to the white population. The authors surveyed 110 healthy individuals and 27 families with FSHD including 55 patients and 74 relatives by pulsed-field gel electrophoresis. The authors report the characteristics of translocation and genotype-phenotype correlation, and their results indicate 4q to 10q translocation contributes to the occurrence of de novo mutation. This leads to a more severe phenotype in the Chinese population comparing to EcoRI allele sizes and the intersexual difference.

Evidence for a novel late-onset Alzheimer disease locus on chromosome 19p13.2.

Late-onset familial Alzheimer disease (LOFAD) is a genetically heterogeneous and complex disease for which only one locus, APOE, has been definitively identified. Difficulties in identifying additional loci are likely to stem from inadequate linkage analysis methods. Nonparametric methods suffer from low power because of limited use of the data, and traditional parametric methods suffer from limitations in the complexity of the genetic model that can be feasibly used in analysis. Alternative methods that have recently been developed include Bayesian Markov chain-Monte Carlo methods. These methods allow multipoint linkage analysis under oligogenic trait models in pedigrees of arbitrary size; at the same time, they allow for inclusion of covariates in the analysis. We applied this approach to an analysis of LOFAD on five chromosomes with previous reports of linkage. We identified strong evidence of a second LOFAD gene on chromosome 19p13.2, which is distinct from APOE on 19q. We also obtained weak evidence of linkage to chromosome 10 at the same location as a previous report of linkage but found no evidence for linkage of LOFAD age-at-onset loci to chromosomes 9, 12, or 21.

GAD2 on chromosome 10p12 is a candidate gene for human obesity.

The gene GAD2 encoding the glutamic acid decarboxylase enzyme (GAD65) is a positional candidate gene for obesity on Chromosome 10p11-12, a susceptibility locus for morbid obesity in four independent ethnic populations. GAD65 catalyzes the formation of gamma-aminobutyric acid (GABA), which interacts with neuropeptide Y in the paraventricular nucleus to contribute to stimulate food intake. A case-control study (575 morbidly obese and 646 control subjects) analyzing GAD2 variants identified both a protective haplotype, including the most frequent alleles of single nucleotide polymorphisms (SNPs) +61450 C>A and +83897 T>A (OR = 0.81, 95% CI [0.681-0.972], p = 0.0049) and an at-risk SNP (-243 A>G) for morbid obesity (OR = 1.3, 95% CI [1.053-1.585], p = 0.014). Furthermore, familial-based analyses confirmed the association with the obesity of SNP +61450 C>A and +83897 T>A haplotype (chi(2) = 7.637, p = 0.02). In the murine insulinoma cell line betaTC3, the G at-risk allele of SNP -243 A>G increased six times GAD2 promoter activity (p < 0.0001) and induced a 6-fold higher affinity for nuclear extracts. The -243 A>G SNP was associated with higher hunger scores (p = 0.007) and disinhibition scores (p = 0.028), as assessed by the Stunkard Three-Factor Eating Questionnaire. As GAD2 is highly expressed in pancreatic beta cells, we analyzed GAD65 antibody level as a marker of beta-cell activity and of insulin secretion. In the control group, -243 A>G, +61450 C>A, and +83897 T>A SNPs were associated with lower GAD65 autoantibody levels (p values of 0.003, 0.047, and 0.006, respectively). SNP +83897 T>A was associated with lower fasting insulin and insulin secretion, as assessed by the HOMA-B% homeostasis model of beta-cell function (p = 0.009 and 0.01, respectively). These data support the hypothesis of the orexigenic effect of GABA in humans and of a contribution of genes involved in GABA metabolism in the modulation of food intake and in the development of morbid obesity.

Transcription within a functional human centromere.

Recent data in yeast and Drosophila suggest a domain-like centromere structure with a modified chromatin core and flanking regions of heterochromatin. We have analyzed a functional human centromere and defined a region of increased chromosome scaffold/matrix attachment that overlaps three other distinct and nonoverlapping domains for constitutive centromere proteins CENP-A and CENP-H, and heterochromatin protein HP1. Transcriptional competency is intact throughout the S/MAR-enriched region and within the CENP-A- and CENP-H-associated chromatin. These results provide insights into the relationship between centromeric chromatin and transcriptional competency in vivo, highlighting the permissibility of transcription within the constitutively modified, nonheterochromatic chromatin of a functional eukaryotic centromere.

NUP98 is fused to adducin 3 in a patient with T-cell acute lymphoblastic leukemia and myeloid markers, with a new translocation t(10;11)(q25;p15).

The nucleoporin 98 gene (NUP98) has been reported to be fused to 13 partner genes in hematological malignancies with 11p15 translocations. Twelve of them have been identified in patients with myeloid neoplasias and only 1, RAP1GDS1 (4q21), is fused with NUP98 in five patients with T-cell acute lymphoblastic leukemia (T-ALL). Three of these patients coexpressed T and myeloid markers, suggesting the specific association of t(4;11)(q21;p15) with a subset of T-ALL originating from an early progenitor, which has the potential to express mature T-cell antigens as well as myeloid markers. We describe here a new NUP98 partner involved in a t(10;11)(q25;p15) in a patient with acute biphenotypic leukemia, showing coexpression of mature T and myeloid markers. The gene involved, located in 10q25, was identified as ADD3 using 3'-RACE. ADD3 codes for the ubiquitous expressed subunit gamma of the adducin protein, and it seems to play an important role in the skeletal organization of the cell membrane. Both NUP98-ADD3 and ADD3-NUP98 fusion transcripts are expressed in the patient. This is the second partner of NUP98 described in T-ALL. Adducin shares with the product of RAP1GDS1, and with all of the nonhomeobox NUP98 partners, the presence of a region with significant probability of adopting a coiled-coil conformation. This region is always retained in the fusion transcript with the NH(2) terminus FG repeats of NUP98, suggesting an important role in the mechanism of leukemogenesis.

Molecular and fluorescence in situ hybridization analysis of a 10;11 rearrangement in a case of infant acute monocytic leukemia.

Fluorescence in situ hybridization (FISH) analysis in a case of infant acute monocytic leukemia M5 revealed a complex rearrangement between chromosomes 10 and 11, leading to the disruption of the MLL gene. Using two painting probes for chromosomes 10 and 11 and a specific probe for the MLL gene localized on 11q23, we observed a paracentric inversion of the 11q13-q23 fragment translocated to 10p12. Molecular analysis showed that AF10 localized on 10p12 was the fusion partner gene of MLL in this rearrangement (10;11). This report underlined the usefulness of FISH and molecular techniques in identifying complex rearrangements.

Periodic morphologic, cytogenetic and clonality evaluation after autologous peripheral blood progenitor cell transplantation in patients with lymphoproliferative malignancies.

BACKGROUND AND OBJECTIVES: Myelodysplastic syndrome (MDS), secondary acute myeloid leukemia (sAML) and clonal karyotypic abnormalities, have been recognized as relatively frequent and potentially serious complications of autologous peripheral blood progenitor cell transplantation (PBPCT) for Hodgkin's disease (HD), non-Hodgkin's lymphoma (NHL) or multiple myeloma (MM). DESIGN AND METHODS: We analyzed 66 patients, undergoing PBPCT for HD, NHL, MM or chronic lymphocytic leukemia (CLL). Patients reported in this study had to be in continuous complete remission after transplantation without receiving chemo-radiotherapy or other biological response modifiers, had to show absence of cytogenetic abnormalities and myelodysplastic features at transplantation and had to have at least 12 months of follow-up. We evaluated the bone marrow, peripheral blood, cytogenetics and clonality (HUMARA) 12 months after the transplant and thereafter every 12 months or every 6 months if lineage dysplasia, clonal or cytogenetic abnormalities were detected. RESULTS: We did not observe MDS/sAML, according to the FAB classification, in 163 assessments of 66 patients over a median follow-up of 25 months (range 12-106) after PBPCT. Twelve patients showed lineage dysplasia: six patients had dyserythropoiesis, 2 patients dysgranulopoiesis, one dysmegakaryocytopoiesis, two patients showed double lineage dysplasia (erythroid and granulocytic), and one patient showed dysgranulopoiesis at the first control acquiring dyserythropoiesis at the next follow-up. We found three cytogenetic abnormalities in the absence of concomitant dysplastic features: transient -5q, -Y, fra(10)(q25). The female patient with the cytogenetic abnormality -5q showed transient unbalanced clonality by HUMARA assay; further controls documented normalization of both clonality and cytogenetics. INTERPRETATION AND CONCLUSIONS: The occurrence of MDS/sAML depends on a variety of risk factors such as the number and type of prior courses of chemo-radiotherapy, total body irradiation in conditioning regimen, cytogenetic and morphologic alterations prior to transplant. This may account for the difference in reporting MDS/sAML after transplantation. The lack of exposure to recognized risk factors for MDS/sAML in our patients may account for the absence of this complication in this study. We consider that the use of stringent morphologic criteria, especially during the first period after PBPCT, combined with cytogenetic, clonality and FISH analyses are necessary for a correct diagnosis of MDS and to overcome the limitations of the FAB and WHO classifications in this setting.