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Bonaglia MC, Giorda R, Massagli A, Galluzzi R, Ciccone R, Zuffardi O. A familial inverted duplication/deletion of 2p25.1-25.3 provides new clues on the genesis of inverted duplications. Eur J Hum Genet 2008; 17:179-86. [PMID: 18813332 DOI: 10.1038/ejhg.2008.160] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
We studied a family in which the same 10 Mb inverted duplication of 2p25.3-p25.1 segregates in two children and their father, all showing a trisomy phenotype. As FISH analysis demonstrated that the duplication was inverted, we suspected that a contiguous terminal deletion was also present, according to the classical inv dup del type of rearrangements. Although FISH with 2p and 2q subtelomeric probes gave normal results, 100 kb resolution array-C/GH (aCGH) showed that, beside the duplication, a 273 kb deletion was also present. The presence of a single-copy region between the deleted and duplicated regions was further suspected through high-resolution aCGH analysis (approximately 20 kb), although only one informative spot having a normal log ratio was detected. The precise structure of the rearrangement was re-defined by real-time PCR and breakpoint cloning, demonstrating the presence of a 2680 bp single-copy sequence between deleted and duplicated regions and the involvement of a simple repeat with the potential for forming a non-B DNA structure. The rearrangement was not mediated by segmental duplications or short inverted repeats, and the double-strand break might have been repaired by non-homologous end joining or microhomology-mediated intrastrand repair. These data highlight the fact that concomitant deletions associated with inverted duplications are very likely to be more frequent than classical cytogenetic methods alone have been able to demonstrate. The phenotypic effects of the trisomy and of the terminal 2p deletion are discussed.
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Bonaglia MC, Giorda R, Beri S, Peters GB, Kirk EP, Hung D, Ciccone R, Gottardi G, Zuffardi O. Concurrent transposition of distal 6p and 20q to the 22q telomere: A recurrent benign chromosomal variant. Eur J Med Genet 2008; 51:148-55. [DOI: 10.1016/j.ejmg.2007.11.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2007] [Accepted: 11/23/2007] [Indexed: 12/08/2022]
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van Bon BWM, Koolen DA, Borgatti R, Magee A, Garcia-Minaur S, Rooms L, Reardon W, Zollino M, Bonaglia MC, De Gregori M, Novara F, Grasso R, Ciccone R, van Duyvenvoorde HA, Aalbers AM, Guerrini R, Fazzi E, Nillesen WM, McCullough S, Kant SG, Marcelis CL, Pfundt R, de Leeuw N, Smeets D, Sistermans EA, Wit JM, Hamel BC, Brunner HG, Kooy F, Zuffardi O, de Vries BBA. Clinical and molecular characteristics of 1qter microdeletion syndrome: delineating a critical region for corpus callosum agenesis/hypogenesis. J Med Genet 2008; 45:346-54. [DOI: 10.1136/jmg.2007.055830] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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De Gregori M, Ciccone R, Magini P, Pramparo T, Gimelli S, Messa J, Novara F, Vetro A, Rossi E, Maraschio P, Bonaglia MC, Anichini C, Ferrero GB, Silengo M, Fazzi E, Zatterale A, Fischetto R, Previderé C, Belli S, Turci A, Calabrese G, Bernardi F, Meneghelli E, Riegel M, Rocchi M, Guerneri S, Lalatta F, Zelante L, Romano C, Fichera M, Mattina T, Arrigo G, Zollino M, Giglio S, Lonardo F, Bonfante A, Ferlini A, Cifuentes F, Van Esch H, Backx L, Schinzel A, Vermeesch JR, Zuffardi O. Cryptic deletions are a common finding in "balanced" reciprocal and complex chromosome rearrangements: a study of 59 patients. J Med Genet 2007; 44:750-62. [PMID: 17766364 PMCID: PMC2652810 DOI: 10.1136/jmg.2007.052787] [Citation(s) in RCA: 217] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 08/09/2007] [Accepted: 08/13/2007] [Indexed: 11/04/2022]
Abstract
Using array comparative genome hybridisation (CGH) 41 de novo reciprocal translocations and 18 de novo complex chromosome rearrangements (CCRs) were screened. All cases had been interpreted as "balanced" by conventional cytogenetics. In all, 27 cases of reciprocal translocations were detected in patients with an abnormal phenotype, and after array CGH analysis, 11 were found to be unbalanced. Thus 40% (11 of 27) of patients with a "chromosomal phenotype" and an apparently balanced translocation were in fact unbalanced, and 18% (5 of 27) of the reciprocal translocations were instead complex rearrangements with >3 breakpoints. Fourteen fetuses with de novo, apparently balanced translocations, all but two with normal ultrasound findings, were also analysed and all were found to be normal using array CGH. Thirteen CCRs were detected in patients with abnormal phenotypes, two in women who had experienced repeated spontaneous abortions and three in fetuses. Sixteen patients were found to have unbalanced mutations, with up to 4 deletions. These results suggest that genome-wide array CGH may be advisable in all carriers of "balanced" CCRs. The parental origin of the deletions was investigated in 5 reciprocal translocations and 11 CCRs; all were found to be paternal. Using customized platforms in seven cases of CCRs, the deletion breakpoints were narrowed down to regions of a few hundred base pairs in length. No susceptibility motifs were associated with the imbalances. These results show that the phenotypic abnormalities of apparently balanced de novo CCRs are mainly due to cryptic deletions and that spermatogenesis is more prone to generate multiple chaotic chromosome imbalances and reciprocal translocations than oogenesis.
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Giorda R, Ciccone R, Gimelli G, Pramparo T, Beri S, Bonaglia MC, Giglio S, Genuardi M, Argente J, Rocchi M, Zuffardi O. Two classes of low-copy repeats comediate a new recurrent rearrangement consisting of duplication at 8p23.1 and triplication at 8p23.2. Hum Mutat 2007; 28:459-68. [PMID: 17262805 DOI: 10.1002/humu.20465] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
We describe a new type of rearrangement consisting of the duplication of 8p23.1 and the triplication of 8p23.2 [dup trp(8p)] in two patients affected by mental retardation and minor facial dysmorphisms. Array-comparative genomic hybridization (CGH), fluorescence in situ hybridization (FISH), and genotyping of polymorphic loci allowed us to demonstrate that this rearrangement is mediated by the combined effects of two unrelated low-copy repeats (LCRs). The first set of LCRs consists of the two clusters of olfactory receptor genes (OR-REPs) lying at 8p23.1. The second type of LCRs consists of a 15-kb segmental duplication, lying in inverted orientation at 8p23.2 and enclosing a nonrepeated sequence of approximately 130 kb, named MYOM2-REP because of its proximity to the MYOM2 gene. The molecular characterization of a third case with a dicentric chromosome 8 demonstrated that the rearrangement had been generated by nonallelic homologous recombination between the two MYOM2-REPs. Based on our findings, we propose a model showing that a second recombination event at the level of the OR-REPs leads to the formation of the dup trp(8p) chromosome. This rearrangement can only arise during meiosis in heterozygous carriers of the polymorphic 8p23.1 inversion, whereas in subjects with noninverted chromosomes 8 or homozygous for the inversion only the dicentric chromosome can be formed. Our study demonstrates that nonallelic homologous recombination involving multiple LCRs can generate more complex rearrangements and cause a greater variety of genomic diseases.
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Beri S, Tonna N, Menozzi G, Bonaglia MC, Sala C, Giorda R. DNA methylation regulates tissue-specific expression of Shank3. J Neurochem 2007; 101:1380-91. [PMID: 17419801 DOI: 10.1111/j.1471-4159.2007.04539.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tissue-specific gene expression can be controlled by epigenetic modifications such as DNA methylation. SHANK3, together with its homologues SHANK1 and SHANK2, has a central functional and structural role in excitatory synapses and is involved in the human chromosome 22q13 deletion syndrome. In this report, we show by DNA methylation analysis in lymphocytes, brain cortex, cerebellum and heart that the three SHANK genes possess several methylated CpG boxes, but only SHANK3 CpG islands are highly methylated in tissues where protein expression is low or absent and unmethylated where expression is present. SHANK3 protein expression is significantly reduced in hippocampal neurons after treatment with methionine, while HeLa cells become able to express SHANK3 after treatment with 5-Aza-2'-deoxycytidine. Altogether, these data suggest the existence of a specific epigenetic control mechanism regulating SHANK3, but not SHANK1 and SHANK2, expression.
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Bonaglia MC, Marelli S, Gottardi G, Zucca C, Pramparo T, Giorda R, Grasso R, Borgatti R, Zuffardi O. Subtelomeric trisomy 21q: a new benign chromosomal variant. Eur J Med Genet 2006; 50:54-9. [PMID: 17055792 DOI: 10.1016/j.ejmg.2006.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Accepted: 07/28/2006] [Indexed: 11/21/2022]
Abstract
The diagnosis of a subtelomeric rearrangement has immediate impact on counseling, particularly in the case of familial rearrangements. However, the existence of subtelomeric imbalances with absent phenotypic effects may hamper genetic counseling, particularly when the rearrangement has not been previously described. We report on a new subtelomeric polymorphism, consisting of a familial subtelomeric rearrangement of chromosome 19 resulting in distal trisomy for 21q, detected in a child with Angelman Syndrome (AS) due to an UBE3A mutation. This report shows that new, previously unknown, benign subtelomeric variants may complicate the correct clinical diagnosis.
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Ciccone R, Mattina T, Giorda R, Bonaglia MC, Rocchi M, Pramparo T, Zuffardi O. Inversion polymorphisms and non-contiguous terminal deletions: the cause and the (unpredicted) effect of our genome architecture. J Med Genet 2006; 43:e19. [PMID: 16648372 PMCID: PMC2564524 DOI: 10.1136/jmg.2005.037671] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Molecular definition at the BAC level of an 8p dicentric chromosome and an 8p deleted chromosome is reported in a patient with two different cell lines. The dicentric, which differed from that generating the recurrent inv dup del(8p) for the location of its break point, originated during the paternal meiosis on the background of the classical 8p23.1 inversion polymorphism. The breakage of this dicentric gave rise to the 8p deleted chromosome which, as a result of the inversion, had two non-contiguous deletions. These findings confirm previous data on 1p distal deletions, showing that at least some of the deletions stem from the breakage of dicentric chromosomes. They suggest that non-contiguous deletions may be frequent among distal deletions. This type of rearrangement can easily be overlooked when two contiguous clones, one absent and the other present by FISH analysis, are taken as boundaries of the deletion break point; in this case only high resolution array-CGH will reveal their real frequency. The definition of such non-contiguous distal deletions is relevant for phenotype/karyotype correlations. There are historical examples of blunders caused by overlooking a second non-contiguous deletion. This paper shows how small scale structural variations, such as common polymorphic inversions, may cause complex rearrangements such as terminal deletions.
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Bedeschi MF, Bonaglia MC, Grasso R, Pellegri A, Garghentino RR, Battaglia MA, Panarisi AM, Di Rocco M, Balottin U, Bresolin N, Bassi MT, Borgatti R. Agenesis of the corpus callosum: clinical and genetic study in 63 young patients. Pediatr Neurol 2006; 34:186-93. [PMID: 16504787 DOI: 10.1016/j.pediatrneurol.2005.08.008] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Revised: 02/22/2005] [Accepted: 08/02/2005] [Indexed: 11/29/2022]
Abstract
This study reports the clinical features of 63 patients with agenesis of the corpus callosum who received in-depth genetic, clinical, and laboratory testing with the aim to contribute to a better description of the large spectrum of associated malformations and to assist clinicians in the diagnosis. Thirty patients manifested complete agenesis and 33 patients displayed partial agenesis. Other associated nervous system malformations were detected in 14 patients with partial agenesis of the corpus callosum (mostly correlated to posterior fossa malformations) and in 10 patients with complete agenesis (more frequently associated with malformations of cortical development). Involvement of organs and apparatus other than the nervous system was present in 41 patients (ascribed to known syndromes in 21 cases). Cytogenetically detectable chromosomal abnormalities (7 patients) and subtelomeric rearrangements (3 patients) were found. Neuromotor skills were impaired in almost all cases (58/63). Mental retardation of different severity was present in 52 cases, whereas 2 patients were borderline and 9 patients had normal intelligence quotient. This study demonstrates that there is no unique prognosis for agenesis of the corpus callosum as this condition is associated with a broad range of clinical manifestations, oscillating between the limits of the norm and severe psychomotor delay.
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Bonaglia MC, Giorda R, Mani E, Aceti G, Anderlid BM, Baroncini A, Pramparo T, Zuffardi O. Identification of a recurrent breakpoint within the SHANK3 gene in the 22q13.3 deletion syndrome. J Med Genet 2005; 43:822-8. [PMID: 16284256 PMCID: PMC2563164 DOI: 10.1136/jmg.2005.038604] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION The 22q13.3 deletion syndrome (MIM 606232) is characterised by neonatal hypotonia, normal to accelerated growth, absent to severely delayed speech, global developmental delay, and minor dysmorphic facial features. We report the molecular characterisation of the deletion breakpoint in two unrelated chromosome 22q13.3 deletion cases. METHODS The deletions were characterised by FISH, checked for other abnormalities by array-CGH, and confirmed by Real-Time PCR, and finally the breakpoints were cloned, sequenced, and compared. RESULTS Both cases show the cardinal features of the 22q13.3 deletion syndrome associated with a deletion involving the last 100 kb of chromosome 22q13.3. The cases show a breakpoint within the same 15 bp repeat unit, overlapping the results obtained by Wong and colleagues in 1997 and suggesting that a recurrent deletion breakpoint exists within the SHANK3 gene. The direct repeat involved in these 22q13 deletion cases is presumably able to form slipped (hairpin) structures, but it also has a strong potential for forming tetraplex structures. DISCUSSION Three cases with a common breakpoint within SHANK3 share a number of common phenotypic features, such as mental retardation and developmental delay with severely delayed or absent expressive speech. The two cases presented here, having a deletion partially overlapping the commercial subtelomeric probe, highlight the difficulties in interpreting FISH results and suggest that many similar cases may be overlooked.
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Pramparo T, Ciccone R, Giorda R, Bonaglia MC, Prieur M, Zollino M, Zuffardi O. O16: Few duplicons make the most noise. Eur J Med Genet 2005. [DOI: 10.1016/j.ejmg.2005.10.052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Ciccone R, Giorda R, Gregato G, Guerrini R, Giglio S, Carrozzo R, Bonaglia MC, Priolo E, Laganà C, Tenconi R, Rocchi M, Pramparo T, Zuffardi O, Rossi E. Reciprocal translocations: a trap for cytogenetists? Hum Genet 2005; 117:571-82. [PMID: 16041583 DOI: 10.1007/s00439-005-1324-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2005] [Accepted: 04/08/2005] [Indexed: 12/01/2022]
Abstract
We report four cases of subjects with phenotypic abnormalities and mental retardation associated with apparently balanced translocations, two inherited and two de novo, which showed, by molecular analysis, a hidden complexity. All the cases have been analyzed with different molecular techniques, including array-CGH, and in two of them the translocation breakpoints have been defined at the level of base pairs via studies in somatic hybrids containing single derivative chromosomes. We demonstrated that all the translocations were in fact complex rearrangements and that an imbalance was present in three of them, thus accounting for the phenotypic abnormalities. In one case, a Prader-Willi subject, we were not able to determine the molecular cause of his phenotype. This study, while confirming previous data showing unexpected complexity in translocations, further underscores the need for molecular investigations before taking for granted an apparently simple cytogenetic interpretation.
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Pramparo T, Grosso S, Messa J, Zatterale A, Bonaglia MC, Chessa L, Balestri P, Rocchi M, Zuffardi O, Giorda R. Loss-of-function mutation of the AF9/MLLT3 gene in a girl with neuromotor development delay, cerebellar ataxia, and epilepsy. Hum Genet 2005; 118:76-81. [PMID: 16001262 DOI: 10.1007/s00439-005-0004-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2005] [Accepted: 05/10/2005] [Indexed: 11/29/2022]
Abstract
The human AF9/MLLT3 gene is a common fusion partner for the MLL gene in translocations t(9;11)(p22;q23) associated with acute myeloid leukemia and acute lymphocytic leukemia. The exact function of the gene is still unknown, although a mouse knock-out model points to a role as a controller of embryo patterning. We report the case of a constitutional translocation t(4;9)(q35;p22) disrupting the AF9/MLLT3 gene in a girl with neuromotor development delay, cerebellar ataxia and epilepsy. Array-CGH analysis at 1 Mbase resolution did not reveal any additional deletions/duplications. We hypothesize a loss-of-function mutation of the AF9/MLLT3 gene, and a possible role for the FAT gene on chromosome 4, in the genesis of the proband's severe neurological phenotype.
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Bonaglia MC, Giorda R, Tenconi R, Pessina M, Pramparo T, Borgatti R, Zuffardi O. A 2.3 Mb duplication of chromosome 8q24.3 associated with severe mental retardation and epilepsy detected by standard karyotype. Eur J Hum Genet 2005; 13:586-91. [PMID: 15657611 DOI: 10.1038/sj.ejhg.5201369] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Chromosome duplications are found in about 2% of subjects with a typical chromosomal phenotype but their frequency is likely to be higher, as suggested by the first array-CGH data. According to the orientation of the duplicated segment, duplications may be in tandem or inverted. The latter are usually associated with a distal deletion. We studied a de novo 2.3 Mb inverted duplication of 8q24.3 without apparently associated deletion in a subject with profound psychomotor retardation, idiopathic epilepsy and growth delay. In spite of its small size, the presence of the rearrangement was suspected on standard karyotypes (approximately 400 bands) and later confirmed by Fluorescent in situ hybridization (FISH) analysis. We hypothesize that the GRINA gene, a glutamate binding subunit of NMDA receptor ion channel lying within the duplicated segment, may be responsible for the epilepsy. This paper confirms that small subtelomeric de novo duplications may be responsible for mental retardation, facial dysmorphisms and/or congenital malformations, although their presence may be overlooked by FISH analysis.
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Giorda R, Cerritello A, Bonaglia MC, Bova S, Lanzi G, Repetti E, Giglio S, Baschirotto C, Pramparo T, Avolio L, Bragheri R, Maraschio P, Zuffardi O. Selective disruption of muscle and brain-specific BPAG1 isoforms in a girl with a 6;15 translocation, cognitive and motor delay, and tracheo-oesophageal atresia. J Med Genet 2004; 41:e71. [PMID: 15173237 PMCID: PMC1735795 DOI: 10.1136/jmg.2003.012260] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
MESH Headings
- Abnormalities, Multiple/genetics
- Abnormalities, Multiple/pathology
- Animals
- Base Sequence
- Brain/metabolism
- Carrier Proteins/genetics
- Cell Line
- Child, Preschool
- Chromosome Banding
- Chromosomes, Human, Pair 15/genetics
- Chromosomes, Human, Pair 6/genetics
- Cognition Disorders/pathology
- Cricetinae
- Cytoskeletal Proteins/genetics
- Developmental Disabilities/pathology
- Dystonin
- Esophageal Atresia/pathology
- Female
- Gene Expression Profiling
- Genotype
- Humans
- In Situ Hybridization, Fluorescence
- Karyotyping
- Male
- Muscles/metabolism
- Mutation
- Nerve Tissue Proteins/genetics
- Polymorphism, Single Nucleotide
- Protein Isoforms/genetics
- Tracheoesophageal Fistula/pathology
- Translocation, Genetic
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41
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Aldred MA, Sanford ROC, Thomas NS, Barrow MA, Wilson LC, Brueton LA, Bonaglia MC, Hennekam RCM, Eng C, Dennis NR, Trembath RC. Molecular analysis of 20 patients with 2q37.3 monosomy: definition of minimum deletion intervals for key phenotypes. J Med Genet 2004; 41:433-9. [PMID: 15173228 PMCID: PMC1735790 DOI: 10.1136/jmg.2003.017202] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Cagliani R, Fortunato F, Giorda R, Rodolico C, Bonaglia MC, Sironi M, D'Angelo MG, Prelle A, Locatelli F, Toscano A, Bresolin N, Comi GP. Molecular analysis of LGMD-2B and MM patients: identification of novel DYSF mutations and possible founder effect in the Italian population. Neuromuscul Disord 2003; 13:788-95. [PMID: 14678801 DOI: 10.1016/s0960-8966(03)00133-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Dysferlin, the protein product of the dysferlin gene (DYSF), has been shown to have a role in calcium-induced membrane fusion and repair. Dysferlin is absent or drastically reduced in patients with the following autosomal recessive disorders: limb-girdle muscular dystrophy type 2B (LGMD-2B), Miyoshi myopathy (MM) and distal anterior compartment myopathy. To date, less than 45 mutations have been described in DYSF and a wide inter- and intra-familial variation in clinical phenotype has been associated with the same mutation. This observation underlines the relevance of any new report describing genotype/phenotype correlations in dysferlinopathic patient and families. Here we present the results of clinical, biochemical and genetic analysis performed on one MM and three LGMD Italian families. By screening the entire coding region of DYSF, we identified three novel mutations (two missense substitutions and one frame shift microdeletion). The possible existence of a founder effect for the Arg959Trp mutation in the Italian population is discussed.
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Bonaglia MC, Giorda R, Cavallini A, Pramparo T, Rocchi M, Borgatti R, Zuffardi O. Distal trisomy 6p and 20q owing to the concurrent transposition of distal 6p and 20q to the 22q telomere: a genomic polymorphism? J Med Genet 2003; 40:e94. [PMID: 12920086 PMCID: PMC1735572 DOI: 10.1136/jmg.40.8.e94] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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44
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Gagliardi C, Bonaglia MC, Selicorni A, Borgatti R, Giorda R. Unusual cognitive and behavioural profile in a Williams syndrome patient with atypical 7q11.23 deletion. J Med Genet 2003; 40:526-30. [PMID: 12843326 PMCID: PMC1735517 DOI: 10.1136/jmg.40.7.526] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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45
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Battisti C, Bonaglia MC, Giglio S, Anichini C, Pucci L, Dotti MT, Zuffardi O, Federico A. De novo double translocation 3;13 and 4;8;18 in a patient with mental retardation and skeletal abnormalities. Am J Med Genet A 2003; 117A:207-11. [PMID: 12599183 DOI: 10.1002/ajmg.a.10149] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A de novo, apparently balanced complex chromosome rearrangement (CCR) involving five chromosomes and six chromosome breakpoints was found in a child with Marfanoid habitus, kyphoscoliosis, axillary pterygium, camptodactyly, joint laxity, and mild mental retardation. Fluorescence in situ hybridization (FISH) revealed a simple translocation involving chromosomes 3 and 13, and a complex rearrangement involving chromosomes 4, 8, and 18 with four breakpoints.
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MESH Headings
- Abnormalities, Multiple/genetics
- Abnormalities, Multiple/pathology
- Bone and Bones/abnormalities
- Child
- Chromosomes, Human, Pair 13/genetics
- Chromosomes, Human, Pair 18/genetics
- Chromosomes, Human, Pair 3/genetics
- Chromosomes, Human, Pair 4/genetics
- Chromosomes, Human, Pair 8/genetics
- Fingers/abnormalities
- Humans
- In Situ Hybridization, Fluorescence
- Intellectual Disability/pathology
- Male
- Translocation, Genetic
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46
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Bonaglia MC, Giorda R, Carrozzo R, Roncoroni ME, Grasso R, Borgatti R, Zuffardi O. 20-Mb duplication of chromosome 9p in a girl with minimal physical findings and normal IQ: narrowing of the 9p duplication critical region to 6 Mb. ACTA ACUST UNITED AC 2003; 112:154-9. [PMID: 12244548 DOI: 10.1002/ajmg.10699] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We studied the case of a girl with a partial 9p duplication, dup(9)(p22.1 --> p13.1). Molecular cytogenetics studies defined the chromosome 9 rearrangement as a direct duplication of 20 Mb from D9S1213 to D9S52. Microsatellite analysis demonstrated the presence of a double dosage of the paternal alleles and demonstrated that the duplication occurred between sister chromatids. The patient's phenotype was almost normal, with a few minor anomalies (dolichocephaly, crowded teeth, high arched palate) and normal IQ. The breakpoint's location in this patient and previously reported cases suggest that the critical region for the 9p duplication syndrome lies within a 6-Mb portion of chromosome 9p22 between markers D9S267 and D9S1213.
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47
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Cagliani R, Bardoni A, Sironi M, Fortunato F, Prelle A, Felisari G, Bonaglia MC, D'Angelo MG, Moggio M, Bresolin N, Comi GP. Two dystrophin proteins and transcripts in a mild dystrophinopathic patient. Neuromuscul Disord 2003; 13:13-6. [PMID: 12467727 DOI: 10.1016/s0960-8966(02)00192-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Two muscle dystrophin transcripts and proteins were detected in a 17-year-old boy with a persistently elevated serum creatine kinase level. A decreased amount of full-length dystrophin and a 360 kDa polypeptide lacking the COOH-terminus were detectable in the patient's muscle biopsy; accordingly, transcript analysis revealed the expression of a wild type messenger RNA together with a shorter frameshifted one. No genomic DNA mutation was found and the presence of a somatic mosaicism was excluded. This dystrophinopathy may be caused by a novel dystrophin gene transcriptional defect, namely aberrant intraexonic splicing.
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Bonaglia MC, Giorda R, Borgatti R, Felisari G, Gagliardi C, Selicorni A, Zuffardi O. Disruption of the ProSAP2 gene in a t(12;22)(q24.1;q13.3) is associated with the 22q13.3 deletion syndrome. Am J Hum Genet 2001; 69:261-8. [PMID: 11431708 PMCID: PMC1235301 DOI: 10.1086/321293] [Citation(s) in RCA: 214] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2001] [Accepted: 05/21/2001] [Indexed: 11/04/2022] Open
Abstract
The terminal 22q13.3 deletion syndrome is characterized by severe expressive-language delay, mild mental retardation, hypotonia, joint laxity, dolichocephaly, and minor facial dysmorphisms. We identified a child with all the features of 22q13.3 deletion syndrome. The patient's karyotype showed a de novo balanced translocation between chromosomes 12 and 22, with the breakpoint in the 22q13.3 critical region of the 22q distal deletion syndrome [46, XY, t(12;22)(q24.1;q13.3)]. FISH investigations revealed that the translocation was reciprocal, with the chromosome 22 breakpoint within the 22q subtelomeric cosmid 106G1220 and the chromosome 12q breakpoint near STS D12S317. Using Southern blot analysis and inverse PCR, we located the chromosome 12 breakpoint in an intron of the FLJ10659 gene and located the chromosome 22 breakpoint within exon 21 of the human homologue of the ProSAP2 gene. Short homologous sequences (5-bp, CTG[C/A]C) were found at the breakpoint on both derivative chromosomes. The translocation does not lead to the loss of any portion of DNA. Northern blot analysis of human tissues, using the rat ProSAP2 cDNA, showed that full-length transcripts were found only in the cerebral cortex and the cerebellum. The FLJ10659 gene is expressed in various tissues and does not show tissue-specific isoforms. The finding that ProSAP2 is included in the critical region of the 22q deletion syndrome and that our proband displays all signs and symptoms of the syndrome suggests that ProSAP2 haploinsufficiency is the cause of the 22q13.3 deletion syndrome. ProSAP2 is a good candidate for this syndrome, because it is preferentially expressed in the cerebral cortex and the cerebellum and encodes a scaffold protein involved in the postsynaptic density of excitatory synapses.
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MESH Headings
- Carrier Proteins/genetics
- Child, Preschool
- Chromosome Aberrations/genetics
- Chromosome Aberrations/physiopathology
- Chromosome Breakage/genetics
- Chromosome Deletion
- Chromosome Disorders
- Chromosomes, Human, Pair 12/genetics
- Chromosomes, Human, Pair 22/genetics
- Exons/genetics
- Gene Expression Profiling
- Humans
- In Situ Hybridization, Fluorescence
- Infant
- Infant, Newborn
- Intellectual Disability/genetics
- Intellectual Disability/physiopathology
- Introns/genetics
- Language Development Disorders/genetics
- Language Development Disorders/physiopathology
- Male
- Molecular Sequence Data
- Nerve Tissue Proteins/genetics
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- Syndrome
- Translocation, Genetic/genetics
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Bonaglia MC, Giorda R, Poggi G, Raggi ME, Rossi E, Baroncini A, Giglio S, Borgatti R, Zuffardi O. Inverted duplications are recurrent rearrangements always associated with a distal deletion: description of a new case involving 2q. Eur J Hum Genet 2000; 8:597-603. [PMID: 10951522 DOI: 10.1038/sj.ejhg.5200509] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
We studied the case of a subject with an inverted duplication of 40 cM of 2q33-q37 concurrent with a 10 cM deletion of the distal 2q, the latter not being detectable by cytogenetics. Microsatellite analysis demonstrated the absence of maternal alleles in the deleted region and a double dosage for one of the maternal alleles in the duplication region. We hypothesised that this type of rearrangement occurs at meiosis I, while the two homologues are synapsed for most of their length. The presence of inverted duplicons in the same chromosome arm would favour the partial refolding of one homologue into itself so leading to the intrachromatid synapsis and recombination of the inverted repeats. The arising recombinant chromosome is deleted for the region beyond the most distal repeat and with the chromatids joined together at the level of the region located between the two duplicons. At meiosis II, the two linked chromatids can join the opposite poles provided that a breakage between the two centromeres occurs leading to a duplicated/deleted chromosome and a simply deleted chromosome. This model can be extended to all the so-called inverted duplication cases and to part of the terminal deletions. In fact the finding that, in our invdup(2q), the entire 40 cM duplication region involves only one of the two maternal alleles, indeed indicates that the abnormal crossover occurs between sister chromatids. The phenotype associated with our 2q rearrangement led us to narrow the critical region for the Albright-like syndrome to 10 cM in the subterminal 2q region.
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Giglio S, Graw SL, Gimelli G, Pirola B, Varone P, Voullaire L, Lerzo F, Rossi E, Dellavecchia C, Bonaglia MC, Digilio MC, Giannotti A, Marino B, Carrozzo R, Korenberg JR, Danesino C, Sujansky E, Dallapiccola B, Zuffardi O. Deletion of a 5-cM region at chromosome 8p23 is associated with a spectrum of congenital heart defects. Circulation 2000; 102:432-7. [PMID: 10908216 DOI: 10.1161/01.cir.102.4.432] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Cytogenetic evidence suggests that the haploinsufficiency of > or =1 gene located in 8p23 behaves as a dominant mutation, impairing heart differentiation and leading to a wide spectrum of congenital heart defects (CHDs), including conotruncal lesions, atrial septal defects, atrioventricular canal defects, and pulmonary valve stenosis. An 8p heart-defect-critical region was delineated, and the zinc finger transcription factor GATA4 was considered a likely candidate for these defects. We narrowed this region and excluded a major role of GATA4 in these CHDs. METHODS AND RESULTS We studied 12 patients (7 had CHD and 5 did not) with distal 8p deletions from 9 families by defining their chromosome rearrangements at the molecular level by fluorescent in situ hybridization and short-tandem repeat analysis. Subjects with 8p deletions distal to D8S1706, at approximately 10 cM from the 8p telomere, did not have CHD, whereas subjects with a deletion that included the more proximal region suffered from the spectrum of heart defects reported in patients with 8p distal deletions. The 5-cM critical region is flanked distally by D8S1706 and WI-8327, both at approximately 10 cM, and proximally by D8S1825, at 15 cM. Neither GATA4 nor angiopoietin-2 (ANGPT2; a gene in 8p23 involved in blood vessel formation) were found to be deleted in some of the critical patients. We also found that CHDs are not related to the parental origin of deletion. CONCLUSIONS Haploinsufficiency for a gene between WI-8327 and D8S1825 is critical for heart development. A causal relationship does not seem to exist between GATA4 and ANGPT2 haploinsufficiency and CHDs.
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