The interstitial deletion of bands q33–35 of long arm of chromosome 7: a review with a new case report

Interstitial or terminal deletion resulting in partial monosomy of various segments of the long arm of chromosome 7 was first recorded over two decades ago. Since then, a number of reports have correlated the severity of clinical manifestations with the length of the deletion involved. However, difficulty remains in defining a so-called "distinct syndrome". We present a new case with the shortest interstitial deletion of the long arm of chromosome 7 bands q33-35, i.e. 46,XX,del(7)(pter----q33::q35----qter). A 4-year-old black female was referred for cytogenetic evaluation due to neurodevelopmental delay. Pertinent physical examination at birth was cleft lip and cleft palate which required corrective surgery. At 2 years of age, a myringotomy tube was inserted for repeated ear infection and a hearing aid was required for conductive deafness. Neurological examination revealed poor eye contact, and severe mental and motor retardation. We reviewed 21 cases of a partial interstitial deletion of varied segments of the long arm of chromosome 7, but we were unable to establish a definite relationship with the deletion of various 7q segments with any specific clinical manifestations.     

Monosomy 18q 12.1→21.1: A recognizable aneuploidy syndrome? Report of a patient and review of the literature

This report of a patient with an interstitial deletion 18q and review of previously described cases suggest a clinically recognizable syndrome. The phenotype appears to result from a microdeletion of part of 18q12.2 or q12.3, or a deletion of parts of both bands. © 1992 Wiley-Liss, Inc.     

A heterozygous,intragenic deletion of CNOT2 recapitulates the phenotype of 12q15 deletion syndrome

Only a few individuals with 12q15 deletion have been described, presenting with a disorder characterized by learning disability, developmental delay, nasal speech, and hypothyroidism. The smallest region of overlap for this syndrome was included in a genomic segment spanning CNOT2, KCNMB4, and PTPRB genes. We report on an additional patient harboring a 12q15 microdeletion encompassing only part of CNOT2 gene, presenting with a spectrum of clinical features overlapping the 12q15 deletion syndrome phenotype. We propose CNOT2 as the phenocritical gene for 12q15 deletion syndrome and its haploinsufficiency being associated with an autosomal dominant disorder, presenting with developmental delay, hypotonia, feeding problems, learning difficulties, nasal speech, skeletal anomalies, and facial dysmorphisms.     

16q22.1 microdeletion and anticipatory guidance

The widespread availability of comparative genomic hybridization (CGH) array analysis has led to the discovery of several genomic microdeletion‐associated syndromes and has identified possible genetic causes for patients with previously unexplained clinical features. We report the case of four unrelated patients who share common clinical characteristics, namely failure to thrive, developmental delay, dysmorphic features, and congenital anomalies. CGH array analysis revealed that all four patients had a de novo microdeletion at 16q22.1. In this case report, we describe the clinical features of these patients and offer possible explanations for how their 16q22.1 microdeletion may account for their symptoms. We also suggest guidelines for the management of 16q22.1 microdeletion based on the phenotypes seen in our patients and the function of the genes affected by this microdeletion.     

Proximal 15q variant as possible pitfall in the cytogenetic diagnosis of Prader-Willi syndrome

A patient with Prader-Willi syndrome showed an elongated proximal 15q, and thus was initially considered to be negative for a proximal 15q deletion. However, repeated high resolution chromosome study demonstrating the DNA-replication banding patterns revealed an obvious deletion/deficiency of the 15q12 equivalent band on that elongated chromosome 15. This deletion was further verified by comparison with the parental chromosomes 15 and the deleted chromosome 15 was of paternal origin. The elongation was due to a long variant of 15q11.2 band, which has previously been shown to be polymorphic/variable. This variable proximal 15q site could potentially mask a deletion if it is too long, or mimic a deletion if it is too short. The use of the DNA-replication banding technique instead of the more widely used trypsin banding technique could alleviate this possible pitfall.     

MCA/MR syndrome with features of Hallermann-Streiff syndrome and 4q deficiency/ 14q duplication

Fryns JP, Borghgraef M, Lemmens F, Van den Berghe H. MCA/MR syndrome with features of Hallermann-Streiff syndrome and 4q deficiency/14q duplication.
Clin Genet 1993: 44: 146–148. © Munksgaard, 1993
In this report we present the clinical history and findings in a female newborn with 4q deficiency/14q duplication, the unbalanced product of a paternal t(4;14)(q33;q32). The clinical symptoms and signs observed in this child up to the age of 14 months were most compatible with the diagnosis of Hallermann-Streiff syndrome.     

Velo-cardio-facial syndrome: Frequency and extent of 22q1l deletions

Velo-cardio-facial. (VCFS) or Shprintzen syndrome is associated with deletions in a region of chromosome 22q11.2 also deleted in DiGeorge anomaly and some forms of congenital heart disease. Due to the variability of phonotype, the evaluation of the incidence of deletions has been hampered by uncertainty of diagnosis. In this study, 54 patients were diagnosed with VCFS by a single group of clinicians using homogeneous clinical criteria independent of the deletion status. Cell lines of these patients were established and the deletion status evaluated for three loci within the commonly deleted region at 22q11.2 using fluorescence in situ hybridization (FISH). In 81% of the patients all three loci were hemizygous. In one patient we observed a smaller interstitial deletion than that defined by the three loci. The phenotype of this patient was not different from that observed in patients with larger deletions. © 1995 Wiley-Liss, Inc.     

Dysmorphic phenotype and neurological impairment in 22 retinoblastoma patients with constitutional cytogenetic 13q deletion

We describe the facial dysmorphic phenotype and the neurological development of a series of 22 retinoblastoma patients sharing a cytogenetically detectable 13q deletion in a retrospective and longitudinal study. In most of the cases, high-resolution banding analysis, morphological analysis, and assessment for neurodevelopmental outcome, as well for organ malformations, were performed. Chromosomal rearrangement involving the RB1 gene included 20 13q interstitial deletions (including 16 de novo deletions) and two (de novo translocations. The most prominent dysmorphic abnormalities were anteverted ear lobes (90%), a high and broad forehead (85%), and a prominent philtrum (65%). This phenotype was associated with severe mental retardation and/or motor impairment at age 2 years in 69% of patients and correlated with the size and the location of the 13q deletion. The survival rate of our series (91%) was not different from that usually seen in retinoblastoma patients.     

SATB2‐associated syndrome: Mechanisms,phenotype, and practical recommendations

The SATB2‐associated syndrome is a recently described syndrome characterized by developmental delay/intellectual disability with absent or limited speech development, craniofacial abnormalities, behavioral problems, dysmorphic features, and palatal and dental abnormalities. Alterations of the SATB2 gene can result from a variety of different mechanisms that include contiguous deletions, intragenic deletions and duplications, translocations with secondary gene disruption, and point mutations. The multisystemic nature of this syndrome demands a multisystemic approach and we propose evaluation and management guidelines. The SATB2‐associated syndrome registry has now been started and that will allow gathering further clinical information and refining the provided surveillance recommendations. © 2016 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc.     

Conventional and molecular cytogenetic findings of myelodysplastic syndrome patients

Abstract Myelodysplastic syndrome (MDS) involves myeloid cells of the bone marrow, which is important in progressive bone marrow insufficiency. Of all MDS patients, 40%–50% have at least one chromosomal rearrangement. Loss of specific chromosomal regions like 5q– and 7q– are usually the secondary cytogenetic abnormalities associated with MDS. In order to detect chromosome abnormalities associated with MDS, bone marrow samples from 26 patients diagnosed as MDS were obtained prior to chemotherapy. Both conventional cytogenetic analyses and fluorescence in situ hybridisation (FISH) methods were performed and locus–specific probes for 5q and 7q were used. Results obtained were compared. Twenty–one patients had normal karyotypes and four patients had abnormal karyotypes, while in one patient we could not obtain metaphases from cultures. Three patients with normal karyotypes revealed del (5q), two patients had del (7q) and one patient had monosomy (7). A total of 10 of 26 patients had chromosome changes visualised by either conventional or molecular cytogenetics (~38.5%). Our results show that both methods are important in diagnosis and follow up of MDS patients. When used together, conventional cytogenetics and FISH detect clinically significant chromosome abnormalities in MDS patients.     

Trisomy 9q3 syndrome: a case report and review of the literature

A girl with partial trisomy 9q is reported. She was characterized by dolichomorphism, abnormalities of the digits, a cardiac defect and craniofacial dysmorphism. A high-resolution analysis revealed the karyotype to be: 46,XX,-3,+ der(3)t(3;9)(q29;q13) de novo. A phenotype-karyotype correlation study in 22 cases of partial trisomies 9q supported the delineation of a trisomy 9q3 syndrome. The smallest region of overlap was confined to 9q32.     

Tricho-Rhino-Phalangeal syndrome type II (Langer-Giedion) with persistent cloaca and prune belly sequence in a girl with 8q interstitial deletion

A patient with the diagnosis of Langer-Giedion syndrome (tricho-rhino-phalangeal syndrome type II) and interstitial 8q deletion was also noted to have persistent cloaca and prune belly sequence. This is the first report of this association. If it postulated that these latter embryonic defects may be due to the chromosome abnormality, supporting the definition of contiguous gene syndrome. © 1992 Wiley-Liss, Inc.     

Unusual clinical features in an Angelman syndrome patient with uniparental disomy due to a translocation 15q15q

We had previously described a patient with an overgrowth syndrome and the chromosome constitution 45,XY,t(15q15q) (Wajntal et al., DNA Cell Biol 1993: 12: 227–231). Clinical reassessment and the use of molecular studies, including methylation analysis with an SNRPN probe, microsatellite analyses of D15S11 , GABRB3 and D15S113 loci, and fluorescence in situ hybridization (FISH) using the SNRPN and GABRB3 probes, are consistent with a diagnosis of Angelman syndrome (AS) due to paternal isodisomy. This is the fourth report case of a translocation 15q15q with paternal uniparental disomy (UPD). Our findings suggest that some patients with clinical features of AS have hyperphagia and obesity with overgrowth, and that these features should not rule out a diagnosis of AS.     

Robertsonian (15q;15q) translocation in a child with Angelman syndrome: Evidence of uniparental disomy

A balanced Robertsonian translocation 45,XY,t(15q15q) was detected in a patient with mental retardation, microcephaly, and hypertonia. Deletion of the 15q11q13 region was unlikely based on fluorescence in situ hybridization studies that revealed hybridization of appropriate DNA probes to both arms of the Robertsonian chromosome. Inheritance of alleles from 13 highly polymorphic DNA markers on chromosome 15 showed paternal uniparental isodisomy. The clinical, cytogenetic, and molecular results are consistent with a diagnosis of Angelman syndrome. © 1996 Wiley-Liss, Inc.     

A brief review of cryptic duplications of 21q as an emerging cause of Down syndrome: practical considerations for accurate detection

We review five cryptic duplications of 21q in patients with Down syndrome (DS) that were inherited from parental balanced translocations. All cases were identified by fluorescence in situ hybridization (FISH) and or DNA diagnosis because the phenotype was inconsistent with the initial cytogenetic studies. These rearrangements seem to escape detection without expanded testing and are probably more frequent than expected. For this reason we propose a series of steps combining objective clinical diagnostic criteria, FISH and DNA methods to achieve an accurate ascertainment.     

9例伴有3q21q26结构重排的血液病患者临床及实验室研究

目的探讨恶性血液病伴有t(3;3)(q21;q26)或inv(3)(q21q26)患者临床及实验室特点。方法骨髓细胞24h短期培养后制备染色体标本,R技术显带后进行核型分析;链霉卵白素-碱性磷酸酶(Streptavidin-AKP,SAP)法检测小巨核细胞;流式细胞仪间接免疫荧光法检测白细胞表面抗原,综合分析临床和实验室资料。结果9例染色体核型为t(3;3)(q21;q26)或inv(3)(q21q26)的患者均存在明显的病态造血,对化学治疗反应差,其中1例行异基因造血干细胞移植后短期复发。结论3q21q26综合征可见于各型恶性血液病,具有独特的临床特征,预后极差。