Supernumerary ring chromosome 8: clinical and molecular cytogenetic characterization in a case report

We report on a 3-year-old male with developmental delay, autistic behavior, and minor abnormalities consistent with trisomy 8 syndrome whose cytogenetic analysis revealed mosaicism for a supernumerary ring chromosome (SRC). Fluorescence in situ hybridization (FISH) studies, using centromeric and yeast artificial chromosome (YAC) probes, were performed to characterize further the supernumerary chromosome. The ring origin has been detected from the short arm of chromosome 8, resulting in r(8)(p10p23.1). Moreover, uniparental disomy (UPD) using microsatellite analysis was excluded. To our knowledge a total of 25 cases, confirmed by FISH, have been reported with either supernumerary marker or ring chromosome 8. We present a detailed clinical and molecular cytogenetic characterization of this additional case in order to better define the genotype-phenotype correlation.     

An interstitial deletion of chromosome 7 at band q21: a case report and review

We report on a girl with moderate developmental delay and mild dysmorphic features. Cytogenetic investigations revealed a de novo interstitial deletion at the proximal dark band on the long arm of chromosome 7 (7q21.1-q21.3) in all analyzed G-banded metaphases of lymphocytes and fibroblasts. Fluorescence in situ hybridization (FISH) and molecular studies defined the breakpoints at 7q21.11 and 7q21.3 on the paternal chromosome 7, with the proximal deletion breakpoint between the elastin gene (localized at 7q11.23) and D7S2517, and the distal breakpoint between D7S652 and the COL1A2 gene (localized at 7q21.3-q22.1). Deletions of interstitial segments at the proximal long arm of chromosome 7 at q21 are relatively rare. The karyotype-phenotype correlation of these patients is reviewed and discussed. The clinical findings of patients with a deletion at 7q21 significantly overlap with those of patients with maternal uniparental disomy of chromosome 7 (matUPD(7)) and Silver-Russell syndrome (SRS, OMIM 180860). Therefore, 7q21 might be considered a candidate chromosomal region for matUPD(7) and SRS.     

Interstitial deletion of chromosome 1 del (1) (q32 q42): case report and review of the literature

We describe the case of a female infant with multiple congenital anomalies who was found to have a de novo distal intestinal del (1) (q32 q42). The clinical features of other reports of similar deletions are briefly reviewed. No characteristic phenotype seems to be as yet definable due to the limited number of cases published.     

Molecular cytogenetic analysis of a de novo interstitial chromosome 10q22 deletion

Interstitial deletions of 10q are rare, and only one patient with a deletion confined to chromosome band 10q22 has been reported so far. We report on a 2 6/12-year-old girl with a constitutional interstitial deletion of one homologue of 10q [karyotype: 46,XX,del(10)(q22.2q22.3)de novo]. Our patient had muscular hypotonia, developmental delay, growth retardation, mild facial dysmorphism, and hypoplastic labia minora. The precise location and extent (3.6 Mb) of the deletion was determined by fluorescence in situ hybridization (FISH) using 16 YAC and BAC clones. The clinical features in our patient are remarkably similar to the previously reported patient with a 10q22.2 deletion.     

Further delineation of the chromosome 14q terminal deletion syndrome

A patient with hypotonia, blepharophimosis, ptosis, a bulbous nose, a long philtrum, upturned corners of the mouth, and mild developmental delay was found to have a small subtelomeric deletion of the long arm of chromosome 14 (q32.31-qter). In comparing her phenotype with previously reported patients with similar 14q deletions, due to either a linear deletion or to a ring chromosome 14, a clinically recognizable terminal 14q microdeletion syndrome was evident. Due to the limited number of cases reported, it was not possible to assign specific features to specific regions of terminal 14q. The comparison of features in cases with a linear deletion of 14qter (n = 19) to those in cases with a deletion due to a ring chromosome 14 (n = 23), both with the same breakpoint in 14q, showed that seizures and retinitis pigmentosa have been found only in patients with ring chromosomes. Several hypotheses are put forward to explain this difference: mitotic instability of ring chromosomes; a telomere position effect in ring chromosomes in which the 14p telomere silences nearby gene(s) on the q-arm; and dose-dependent gene(s) involved in seizures and retinitis pigmentosa located on the short arm of chromosome 14. In our opinion, only seizures may be explained by the mitotic instability of ring chromosomes, while both seizures and retinitis pigmentosa may be explained by silencing of gene(s) on 14q by the 14p telomere; the third hypothesis seems unlikely to explain either symptom.     

Molecular cytogenetic analysis of a de novo interstitial deletion of 5q23.3q31.2 and its phenotypic consequences

We report a 2(3/12)-year-old boy with a constitutional interstitial deletion of 5q,46,XY,del(5)(q23.3q31.2) de novo. Clinical manifestations in this patient included failure to thrive, psychomotor retardation, mild facial dysmorphic features, and long and slender fingers and toes. The precise location and extent (9.5 Mb) of the deletion was determined by fluorescence in situ hybridization (FISH) using 19 YAC and BAC clones. Comparison of the present patient with six other patients with deletions of chromosomal bands 5q22-5q31 allowed further delineation of a constitutional del5q22q31 syndrome. The main features of this syndrome are psychomotor retardation, failure to thrive, hypotonia, hypoplastic muscles, cleft or high arched palate, low-set and dysplastic ears, flat nasal bridge, downslanting palpebral fissures, hypertelorism, anteverted nostrils, and micro- and/or retrognathia.     

Chromosome 1q terminal deletion resulting fromde novo translocation with an acrocentric chromosome

Summary Distal deletion of chromosome 1q has been reported in nearly 30 patients, all being associated with a deletion ranging from the 1q42 or q43 band to 1qter region. Here, we describe a girl with 1q terminal deletion resulting from an unbalancedde novo translocation t(1;D or G)(q44; p11), as revealed by the presence of a satellited feature and an NOR-stained region at the tip of 1q. We suggest that most of the phenotypic abnormalities seen in patients with 1q distal deletion are attributable to the monosomy for band 1q44.     

Bladder exstrophy and extreme genital anomaly in a patient with pure terminal 1q deletion: expansion of phenotypic spectrum

We describe a 5 2/12 years old male patient with a de novo deletion 1q43q44 of approximately 10.4 Mb in size. The boy presented with the classic features of chromosome 1q43q44 deletion syndrome including growth and psychomotor retardation, microcephaly, distinct facial features and various midline defects as agenesis of corpus callosum, cardiac and urogenital anomalies. Fronto-parietal simplified gyral pattern was an additional neuroimaging finding. The urogenital anomalies in our patient were remarkable in form of bladder exstrophy and severe hypogenitalism with a marked hypoplastic scrotum, small sized retractile testis and absent phallus. To the best of our knowledge, bladder exstrophy and absence phallus have not been previously reported in terminal deletion 1q43q44 syndrome. This report provides further evidence of phenotype-genotype correlation and expands the phenotypic spectrum of midline defects described with this syndrome.     

Mild phenotypic manifestations of terminal deletion of the long arm of chromosome 4: clinical description of a new patient

We present clinical and developmental data on a patient with a de novo terminal deletion of the long arm of chromosome 4. Cytogenetic studies after G-banding revealed the karyotype 46,XY,del(4)(q34). The 4-year-old male showed mild facial dysmorphism, moderate mental retardation with speech retardation, and marked deficits in gross motor skills. Our patient is the second with this deletion described in the literature. In both patients the phenotype was characterized by mild to moderate mental retardation, abnormalities of the pinnae, and nonspecific facial dysmorphism. The mild phenotype might explain why only two patients with this deletion have been described so far.     

New chromosome aberration: duplication of a large part of chromosome 4q and partial deletion of chromosome 1q

We describe a preterm female infant with multiple anomalies who has a duplication of a large part of 4q and partial deletion of chromosome 1q. Her karyotype was interpreted to be 46,XX,-1,+der(1),t(1;4) (q44;q23 or 24)mat. She is the first patient with an unbalanced translocation involving chromosomes 4 and 1. There is a substantial amount of concordance between the phenotypic features of this patient and those described in the context of partial deletion 1q. The extensive duplication of 4q has no dominant clinical effects in the present infant. These facts support the general concept of much more deleterious effects of deletions versus duplications in human species.     

Partial deletion 11q: report of a case with a large terminal deletion 11q21-qter without loss of telomeric sequences, and review of the literature

We describe the cytogenetic findings and the dysmorphic features in a stillborn girl with a large de novo terminal deletion of the long arm of chromosome 11. The karyotype was 46,XX,del(11)(q21qter). By reviewing previous reports of deletion 11q, we found that cleft lip and palate are most frequently seen in proximal 11q deletions involving 11q21. Telomeric staining using the PRINS technique demonstrated normal telomeric sequences in the deleted chromosome 11.     

Small terminal deletion of 1p and duplication of 1q: Cytogenetics,FISH studies,and clinical observations at newborn and at age 16 years

A small, extra chromosome segment added to 1p was found by Q-banding 16 years ago in a newborn baby with low birth weight, short stature, wide open fontanelle, small palpebral fissures, depressed nose bridge, and inguinal hernia. This chromosome abnormality has been characterized recently with G-banding and fluorescence in situ hybridization using multiple DNA probes. The karyotype is now described as 46,XY, der(1)(qter→p36.13::q42.3→qter), representing a small deletion of 1p36.13-pter and a small duplication of 1q42.3-qter. Re-examination of this patient at age 16 years showed marked psychomotor delay, severely accentuated dorsal kyphosis and scoliosis, pectus excavatum, and other anomalies but no clinical signs of neuroblastoma. Comparison of the clinical findings in this case with those described in the patients having either a deletion of 1p36-pter or a duplication of 1q42-qter further illustrated the complexity of the genotype-phenotype relationship. Am. J. Med. Genet. 86:118–123, 1999. © 1999 Wiley-Liss, Inc.     

Case with autistic syndrome and chromosome 22q13.3 deletion detected by FISH

Autism is a rare neurodevelopmental disorder with a strong genetic component. Co-occurrence of autism and chromosomal abnormalities is useful to localize candidate regions that may include gene(s) implicated in autism determinism. Several candidate chromosomal regions are known, but association of chromosome 22 abnormalities with autism is unusual. We report a child with autistic syndrome and a de novo 22q13.3 cryptic deletion detected by FISH. Previously described cases with 22q13.3 deletions shared characteristic developmental and speech delay, but autism was not specifically reported. This case emphasizes a new candidate region that may bear a gene involved in autism etiopathogenesis. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:839-844, 2000.     

Interstitial deletion of chromosome 10q23: a new case and review.

A new case of a deletion of 10q23 is described. Only two other deletions involving this region have been previously noted. A review of clinical features of these three children did not show a distinct pattern of dysmorphic features. Other interstitial deletions of 10q are listed.     

Tetraploidy and 5q deletion in myelodysplastic syndrome: a case report

Tetraploidy is a very rare cytogenetic abnormality in myelocytic malignancies, and its significance is unclear to date. We report here on a 68-year-old male diagnosed with myelodysplastic syndrome/refractory anemia with excess blasts (MDS/RAEB). Cytogenetic analysis of his bone marrow biopsy at initial clinical presentation and in subsequent studies revealed the presence of two abnormal clones, 92,XXYY and 92,XXYY,del(5)(q13q33). Interphase fluorescence in situ hybridization analysis of abnormal cells confirmed interstitial deletion in 5q, demonstrated predominance of the tetraploid clone and persistent presence of the tetraploid clone with 5q deletion. The patient was not responsive to Revlimid (lenalidomide) treatment, which is routinely used in patients with 5q– syndrome. However, a subsequent course of therapy with the methyl-transferase inhibitor decitabine resulted in clinical and cytogenetic remission. Our data suggest that the unique complex abnormality of tetraploidy and 5q deletion described here for the first time in MDS is characterized by distinct disease etiology, the mechanism of which could involve epigenetic inactivation of gene expression via methylation. ©2008 Elsevier Inc. All rights reserved.     

Subtelomeric deletion of chromosome 10p15.3: Clinical findings and molecular cytogenetic characterization

We describe 19 unrelated individuals with submicroscopic deletions involving 10p15.3 characterized by chromosomal microarray (CMA). Interestingly, to our knowledge, only two individuals with isolated, submicroscopic 10p15.3 deletion have been reported to date; however, only limited clinical information is available for these probands and the deleted region has not been molecularly mapped. Comprehensive clinical history was obtained for 12 of the 19 individuals described in this study. Common features among these 12 individuals include: cognitive/behavioral/developmental differences (11/11), speech delay/language disorder (10/10), motor delay (10/10), craniofacial dysmorphism (9/12), hypotonia (7/11), brain anomalies (4/6) and seizures (3/7). Parental studies were performed for nine of the 19 individuals; the 10p15.3 deletion was de novo in seven of the probands, not maternally inherited in one proband and inherited from an apparently affected mother in one proband. Molecular mapping of the 19 individuals reported in this study has identified two genes, ZMYND11 (OMIM 608668) and DIP2C (OMIM 611380; UCSC Genome Browser), mapping within 10p15.3 which are most commonly deleted. Although no single gene has been identified which is deleted in all 19 individuals studied, the deleted region in all but one individual includes ZMYND11 and the deleted region in all but one other individual includes DIP2C. There is not a clearly identifiable phenotypic difference between these two individuals and the size of the deleted region does not generally predict clinical features. Little is currently known about these genes complicating a direct genotype/phenotype correlation at this time. These data however, suggest that ZMYND11 and/or DIP2C haploinsufficiency contributes to the clinical features associated with 10p15 deletions in probands described in this study. ? 2012 Wiley Periodicals, Inc.     

Small terminal deletion of 1p and duplication of 1q: cytogenetics, FISH studies, and clinical observations at newborn and at age 16 years.

A small, extra chromosome segment added to 1p was found by Q-banding 16 years ago in a newborn baby with low birth weight, short stature, wide open fontanelle, small palpebral fissures, depressed nose bridge, and inguinal hernia. This chromosome abnormality has been characterized recently with G-banding and fluorescence in situ hybridization using multiple DNA probes. The karyotype is now described as 46,XY, der(1)(qter-->p36.13::q42.3-->qter), representing a small deletion of 1p36.13-pter and a small duplication of 1q42.3-qter. Re-examination of this patient at age 16 years showed marked psychomotor delay, severely accentuated dorsal kyphosis and scoliosis, pectus excavatum, and other anomalies but no clinical signs of neuroblastoma. Comparison of the clinical findings in this case with those described in the patients having either a deletion of 1p36-pter or a duplication of 1q42-qter further illustrated the complexity of the genotype-phenotype relationship.