Partial Trisomy 2p Research Articles

A Partial Trisomy 2p(p21→pter) Derived from a Paternal t(2;4)(p21;q33) Karyotype

A Partial Trisomy 2p(p21→pter) Derived from a Paternal t(2;4)(p21;q33) KaryotypeWe describe a 7-year-old boy with additional material on 4q whose karyotype was 46, XY, der(4) t(2;4)(p21: q33). The father's karyotype was 46, XY, t(2;4)(p21;q33) and the mother's was normal. These results indicate that the extra material on 4q in the patient originated from the father's chromosome 2p. The patient had dysmorphic facial features, prominent ears, long fingers, developmental delay, speech delay and suffered from seizures.

Partial trisomy 9p22 to 9p24.2 in combination with partial monosomy 9pter in a Syrian girl

BackgroundPartial trisomy of the short arm of chromosome 9 is among the most common autosomal structural chromosomal anomalies leading to chromosomal imbalance in human. Clinical characteristics are craniofacial dysmorphism including hypertelorism, prominent nose, deep-set eyes, and down-slanting palpebral fissures. The degree of clinical severity in partial trisomy 9p roughly correlates with the size of the chromosomal imbalance. Therefore, breakpoints as well as clinical findings need to be precisely defined for differential diagnosis.ResultsChromosomes of a young female were analyzed due to primary amenorrhea, short stature, developmental delay and a characteristic facial appearance. Cytogenetic analysis using GTG banding identified a karyotype 46, XX, add(9pter). Surprisingly the application of high resolution molecular cytogenetic techniques characterized a partial trisomy 9p24.2-p22 and partial monosomy 9pter-p24.2. To the best of our knowledge only four similar case were reported by now.ConclusionAttempts for genotype-phenotype correlations for partial trisomy 9p might have been hampered by the fact that more complex, cryptic aberrations were neither considered nor detected in comparable clinical cases.

Trisomy 21 with a Small Supernumerary Marker Chromosome Derived from Chromosomes 13/21 and 18

Trisomy 21 with a Small Supernumerary Marker Chromosome Derived from Chromosomes 13/21 and 18We describe a trisomy 21 with a small supernumerary marker chromosome (sSMC) derived from chromosomes 13/21 and 18 in which the karyotype was 48, XY, +der(13 or 21)t(13 or 21;18)(13 or 21pter→13q11 or 21q11.1::18p 11.21→18pter),+21. Of the 35 case reports in the literature for a karyotype 48, XN, +21,+mar, in only 12 was the origin of the sSMC determined by fluorescence in situ hybridization (FISH), and only one was a der(13 or 21) and none were derived from two chromosomes. The influence of the partial trisomy 18p on the clinical outcome was hard to determine, however, there are reports on clinically healthy subjects for partial trisomy 18p.

Clinical Manifestations of Partial Trisomy 4p

Clinical Manifestations of Partial Trisomy 4pWe made the diagnosis prenatally from cytogenetic analysis of amniocytes cultured following amniocentesis performed at 20 weeks' gestation on a woman in whom ultrasound examination of the female fetus showed severe growth retardation, lung and kidney hypoplasia, and a congenital heart defect. Analysis revealed a de novo trisomy of the terminal short arm of chromosome 4 (4p16.1-pter). The parents opted to terminate the pregnancy. Fetopathological examination showed dysmorphic features and other abnormalities consistent with clinical manifestations of partial trisomy 4p.

Cytogenetic and molecular characterization of a partial trisomy 2p arising from inverted duplication of 2p with terminal deletion of 2pter

Partial trisomy 2p is typically associated with partial monosomy of another chromosomal segment and results from a balanced translocation in one of the parents. Inverted duplications with terminal deletions have been reported in an increasing number of chromosomes. Several cases initially interpreted as terminal duplications have instead been documented to represent inverted duplications with terminal deletions. Inv dup del(2p) has been reported in patients who manifest the clinical findings of trisomy 2p syndrome. Here we report on a 2-month-old girl with inv dup del(2p) and clinical manifestations that overlap those found commonly in partial 2p trisomy, as previously reported in the literature. Her clinical picture helps delineate the phenotype of 2p duplication disorders.

Case Report Oropharyngeal dysphagia and language delay in partial trisomy 9p: case report

The phenotype of partial trisomy 9p includes global developmental delay, microcephaly, bulbous nose, downturned oral commissures, malformed ears, hypotonia, and severe cognitive and language disorders. We present a case report and a comparative review of clinical findings on this condition, focusing on speech-language development, cognitive abilities and swallowing evaluation. We suggest that oropharyngeal dysphagia should be further investigated, considering that pulmonary and nutritional disorders affect the survival and quality of life of the patient. As far as we know, this is the first study of a patient with partial trisomy 9p described with oropharyngeal dysphagia.

A new cause of ambiguous genitalia: multiple malformation Syndrome related to an unbalanced translocation [46,xy t(7;16)

We report the case of a three years old male child who showed ambiguous genitalia in a setting of multiple malformations. Disorders of sex development (DSD) are due to many different causes, such as chromosome abnormalities, or alterations in transcription factors, receptors, and hormones implicated in sexual differentiation during fetal life. Here we describe a case of partial deletion 7q ter associated with partial trisomy 16p as a new chromosome anomaly associated with ambiguous genitalia. We have attempted to analyse the individual contributions of chromosomes 7 and 16 in the pathogenesis of the sex malformation in our patient.

De novo complex intra chromosomal rearrangement after ICSI: characterisation by BACs micro array-CGH

BackgroundIn routine Assisted Reproductive Technology (ART) men with severe oligozoospermia or azoospermia should be informed about the risk of de novo congenital or chromosomal abnormalities in ICSI program. Also the benefits of preimplantation or prenatal genetic diagnosis practice need to be explained to the couple.MethodsFrom a routine ICSI attempt, using ejaculated sperm from male with severe oligozoospermia and having normal karyotype, a 30 years old pregnant woman was referred to prenatal diagnosis in the 17th week for bichorionic biamniotic twin gestation. Amniocentesis was performed because of the detection of an increased foetal nuchal translucency for one of the fetus by the sonographic examination during the 12th week of gestation (WG). Chromosome and DNA studies of the fetus were realized on cultured amniocytesResultsConventional, molecular cytogenetic and microarray CGH experiments allowed us to conclude that the fetus had a de novo pericentromeric inversion associated with a duplication of the 9p22.1-p24 chromosomal region, 46,XY,invdup(9)(p22.1p24) [arrCGH 9p22.1p24 (RP11-130C19 → RP11-87O1)x3]. As containing the critical 9p22 region, our case is in coincidence with the general phenotype features of the partial trisomy 9p syndrome with major growth retardation, microcephaly and microretrognathia.ConclusionThis de novo complex chromosome rearrangement illustrates the possible risk of chromosome or gene defects in ICSI program and the contribution of array-CGH for mapping rapidly de novo chromosomal imbalance.

Prenatal Diagnosis of Partial Trisomy 3p (3p21→pter) and Partial Monosomy 11q (11q23→qter) Associated with Abnormal Sonographic Findings of Holoprosencephaly, Orofacial Clefts, Pyelectasis and a Unilateral Duplex Renal System

Patients with partial trisomy 3p seldom present major dysmorphic features, and holoprosencephaly occurs in only 10% of the cases with partial trisomy 3p. It has been suggested that multiple genetic hits or environmental exposures are required for the clinical expression of holoprosencephaly. At 16 weeks of gestation, prenatal sonography identified a fetus with holoprosencephaly, orofacial clefts, pyelectasis, and a unilateral duplex renal system. Amniocentesis revealed the karyotype of 46,XX,der(11)t(3;11)(p21;q23)pat with partial trisomy 3p (3p21-->pter) and partial monosomy 11q (11q23-->qter). The pregnancy was subsequently terminated. Postnatally, the proband showed hypotelorism, a depressed nasal bridge, orofacial clefts and holoprosencephaly-premaxillary agenesis. The present case provides evidence that partial trisomy 3p/monosomy 11q can be a genetic cause of holoprosencephaly and del(11)(q23-->qter) is associated with a duplex renal system.

Partial 5p monosomy or trisomy in 11 patients from a family with a t(5;15)(p13.3;p12) translocation

A family with six alive patients with partial monosomy 5p and five with partial trisomy 5p due to a t(5;15)(p13.3;p12) translocation is reported. The translocation was present in four generations with eight balanced carriers. This is the first molecular-cytogenetic and clinical study with both syndromes present in the same family. Using fluorescence in situ hybridization (FISH) with bacterial artificial chromosome (BAC) probes, the breakpoint was mapped to 5p13.3, in the interval corresponding to the BAC clone RP11-1079N14, thereof resulting a 5pter-5p13.3 deletion or duplication of approximately 32 Mb. These chromosome imbalances can be considered pure, since the other imbalance produced involving chromosome 15p has no phenotypic effect. The presence of several individuals with 5p monosomy and 5p trisomy in the same family is valuable for a better delineation of both syndromes.

Partial trisomy and partial monosomy resulting from a reciprocal segregating in a large family

Partial trisomy 7p with partial monosomy 9p is a rare disorder with only 3 cases reported. Both these abnormalities i.e., partial trisomy 7p and partial monosomy 9p result in distinct clinical phenotypes. However, patients with combined 7p trisomy/9p monosomy present with a phenotype consistent with trisomy 7p. We present a fourth case of trisomy 7p/monosomy 9p with long term follow-up and document the medical complications associated with this disorder. Long term follow-up of patients with chromosome abnormalities provides a unique opportunity to document the medical history and complications associated with such abnormalities.

Corpus Callosum Agenesis in Trisomy 8p11.23 and Monosomy 4q34 Because of Maternal Translocation

We report on a 3-year-old boy with partial trisomy 8 p11.23-->pter and partial monosomy 4q34-->qter, associated with developmental delay, complete agenesis of the corpus callosum, and mild dysmorphic features. Although agenesis of the corpus callosum is not a rare finding among chromosomal abnormalities, partial trisomy 8p together with partial monosomy 4q, resulting from a maternal translocation, was not previously reported, to the best of our knowledge.

Cytogenetic studies of 24 renal epithelial tumors with von Hippel-Lindau and fragile histidine triad protein expression correlation.

Abstract Context.—Deletion of the short arm of chromosome 3 (3p deletion) is a cytogenetic abnormality generally associated with clear cell renal cell carcinoma, the most aggressive form of renal epithelial tumor. Objective.—To cytogenetically characterize 24 renal tumors in order to check the incidence and the type of 3p deletions, as well as to identify new genes putatively participating in renal tumorigenesis and test the protein products of the von Hippel-Lindau (VHL) and fragile histidine triad (FHIT) genes. Design.—We analyzed 24 renal tumors by conventional cytogenetics, comparative genomic hybridization, and fluorescence in situ hybridization. We then performed a comparative expression study of the proteins pVHL and Fhit. Results.—In our series of 24 renal tumors, the 3p deletion was the most frequent genetic alteration (15/24); the other features were partial trisomy 5q, 8p deletion, and monosomy 9 and 14. The 3p deletion was long and terminal, and no interstitial deletion was identified. By immu...

Cytogenetic Studies of 24 Renal Epithelial Tumors With von Hippel-Lindau and Fragile Histidine Triad Protein Expression Correlation

Deletion of the short arm of chromosome 3 (3p deletion) is a cytogenetic abnormality generally associated with clear cell renal cell carcinoma, the most aggressive form of renal epithelial tumor. To cytogenetically characterize 24 renal tumors in order to check the incidence and the type of 3p deletions, as well as to identify new genes putatively participating in renal tumorigenesis and test the protein products of the von Hippel-Lindau (VHL) and fragile histidine triad (FHIT) genes. We analyzed 24 renal tumors by conventional cytogenetics, comparative genomic hybridization, and fluorescence in situ hybridization. We then performed a comparative expression study of the proteins pVHL and Fhit. In our series of 24 renal tumors, the 3p deletion was the most frequent genetic alteration (15/24); the other features were partial trisomy 5q, 8p deletion, and monosomy 9 and 14. The 3p deletion was long and terminal, and no interstitial deletion was identified. By immunohistochemistry, we found that for the 2 genes of interest, VHL and FHIT, loss or decrease in protein expression were very frequently observed in clear cell renal cell carcinoma and not always associated with a 3p deletion (14/20 in clear cell renal cell carcinoma). Our studies characterize the 3p deletion as long and terminal and identify no interstitial deletion in that chromosome. Fhit and pVHL protein expression loss appear to be independent, as they can be dissociated. Our data are supportive of a role for FHIT (in addition to VHL) in renal tumorigenesis. No other gene with particular potential interest in renal tumorigenesis could be identified among the selected genes.

Larsen‐like phenotype associated with partial trisomy 3p and monosomy 5p

We report on a fetus with radiographic features of Larsen Syndrome (LS) and unbalanced 3;5 translocation. Recently LS was shown to be caused by mutations in FLNB gene which maps on 3p14.3. Comparative genomic hybridization (CGH) was performed to search for genomic imbalances. Fluorescence in situ analysis (FISH) was done with BAC clone RP11-754F19 probe from the FLNB gene region (3p14.3). CGH showed a large loss of the chromosome 5 short arm and a gain of half of the short arm of chromosome 3 resulting from a derivative chromosome 5. FISH analysis with FLNB probe demonstrated that it was not triplicated. Thus, we excluded the role of a gene dosage effect of FLNB in abnormal craniofacial development in this fetus. To our knowledge, this is the first report of Larsen-like phenotype associated with unbalanced translocation resulting in partial trisomy 3p and monosomy 5p.

Partial monosomy Xq(Xq23 → qter) and trisomy 4p(4p15.33 → pter) in a woman with intractable focal epilepsy, borderline intellectual functioning, and dysmorphic features

Studies of epilepsy associated with chromosomal abnormalities may provide information about clinical and EEG phenotypes and possibly to identify new epilepsy genes. We describe a female patient with intractable focal epilepsy, borderline intellectual functioning, and facial dysmorphisms, in whom genetic study (i.e., karyotype and array-CGH analysis) revealed a distal trisomy 4p and distal monosomy Xq. Although any genetic hypothesis remains speculative, several genes are located in the 4p chromosome segment involved in the rearrangement, some of which may be related to epilepsy.

Partial Trisomy 3p and Monosomy 7p Associated with Tetralogy of Fallot and Infantile Seizure

A 7-month-old female infant was referred because of hypothyroidism, seizure, respiratory distress syndrome, and tetralogy of Fallot (TOF) with hypoxic spell. Her father and 24-year-old mother were healthy and nonconsanguineous. There was no family history of congenital malformations. The mother denied any exposure to alcohol, teratogenic agents or infectious diseases during this pregnancy. She received regular prenatal examinations at a local clinic. The infant was born prematurely at 35 weeks of gestation. However, bradycardia, restlessness, cyanosis, gasping respiration, upgaze, and episodes of seizure developed soon after delivery. The infant’s external appearance was grossly normal, and the extremities were freely movable. The body weight was less than third percentile with growth restriction. Serial studies were arranged. Echocardiography revealed an atrial septal defect, a large ventricular septal defect, right ventricular hypertrophy, and severe pulmonary stenosis that were consistent with TOF. Brain sonography revealed moderate dilatation of lateral and third ventricles, in favor of the diagnosis of benign extracerebral fluid collection. Conventional cytogenetic studies performed on the

Bilateral Semilunar Valve Dysplasia in a Patient with Inverted Duplication 2p25–22

Here we report a patient with partial trisomy 2p and congenital dysplasia of the semilunar valves. To our knowledge, this is the first case of 2p duplication with developmental defects of both semilunar valves and suggests that genes on this region contribute to the formation of the semilunar valves.

A case of de novo partial tetrasomy of distal 6p and review of the literature

We report on a 3-year-old girl with bilateral eyelid colobomas, bulbous nose, blepharophimosis, blepharoptosis, sensorineural hearing loss, atrial septal defect, psychomotor retardation, and growth delay. Cytogenetic analysis showed additional material of unknown origin on the short arm of chromosome 8. Whole chromosome paint FISH identified the additional material to originate from chromosome 6. Subtelomeric metaphase FISH analysis detected a bright signal pattern for the 6p subtelomere probe on the derivative 8 as well as two short arm signals for the normal chromosomes 6. Interphase FISH with the 6p subtelomere probe demonstrated four 6p signals. Interestingly, metaphase FISH with a probe for the 8p subtelomere region demonstrated a signal for 8p just proximal to the translocated material. Comparative genomic hybridization studies confirmed tetrasomy of the 6p subtelomere region from 6p25.1 --> 6p25.3. Thus our patient represents the first reported case of "pure" partial tetrasomy 6p, meaning the tetrasomy was not associated with a significant deletion of chromosome arm 8p. We compare here this case with previously reported cases of partial trisomy 6p and the resulting phenotypes.

Small supernumerary marker chromosome causing partial trisomy 6p in a child with craniosynostosis

We report on a child with a small supernumerary marker chromosome (sSMC) causing partial trisomy 6p. The child showed a phenotype consisting of neonatal craniosynostosis, microcephaly, and borderline developmental delay. By molecular techniques the sSMC has been shown to contain approximately 16 Mb of genomic DNA from 6p21.1 to 6cen, being de novo and of maternal origin.