scholarly journals Phenotypic and Molecular Cytogenetic Analysis of a Case of Monosomy 1p36 Syndrome due to Unbalanced Translocation

2020 ◽  
Vol 11 (5-6) ◽  
pp. 284-295
Author(s):  
Dalia F. Hussen ◽  
Alaa K. Kamel ◽  
Mona K. Mekkawy ◽  
Engy A. Ashaat ◽  
Mona O. El Ruby
Keyword(s):  
Intellectual Disability ◽  
Microarray Analysis ◽  
Cytogenetic Analysis ◽  
Copy Number ◽  
Clinical Manifestations ◽  
Copy Number Variations ◽  
Chromosomal Microarray Analysis ◽  
Fish Analysis ◽  
Unbalanced Translocation ◽  
Genotype Correlation

Monosomy 1p36 syndrome is one of the most common submicroscopic deletion syndromes, which is characterized by the presence of delayed developmental milestones, intellectual disability, and clinically recognizable dysmorphic craniofacial features. The syndrome comprises 4 cytogenetic groups including pure terminal deletions, interstitial deletions, complex rearrangements, and derivative chromosomes 1 due to unbalanced translocations, where unbalanced translocations represent the least percentage of all cases of monosomy 1p36 (7%). Most patients with monosomy 1p36 due to an unbalanced translocation can be cytogenetically diagnosed using conventional techniques. However, chromosomal microarray analysis is mandatory in these cases to detect copy number variance and size of the deletion and allows for setting a phenotype-genotype correlation. Here, we studied a 1.5-year-old female patient who showed intellectual disability, delayed milestones, hypotonia, seizures, and characteristic dysmorphic features including brachycephaly, straight eyebrows, deep-set eyes, downslanting palpebral fissures, midface hypoplasia, depressed nasal bridge, long philtrum, and pointed chin. Conventional cytogenetic analysis (CCA), microarray study, and fluorescence in situ hybridization (FISH) analysis were performed. CCA showed a translocation involving chromosomes 1 and 21, 45,XX,der(1)t(1;21)(p36.32;q21.1)dn. Microarray analysis revealed copy number losses at both 1p36 and proximal 21q. FISH confirmed the presence of the 1p36 deletion, but was not performed for 21q. We have concluded that phenotype-genotype correlation for monosomy 1p36 syndrome can be performed for the fundamental clinical manifestations; however, the final aspect of the syndrome depends on composite factors. Monosomy 1p36 due to unbalanced translocation may present either classically or with additional altered features of various severity based on the copy number variations involving different chromosomes.

scholarly journals Performance of Chromosomal Microarray Analysis for Detection of Copy Number Variations in Fetal Echogenic Bowel

2021 ◽  
Vol Volume 14 ◽  
pp. 1431-1438
Author(s):  
Xiangqun Fan ◽  
Hailong Huang ◽  
Xiyao Lin ◽  
Huili Xue ◽  
Meiying Cai ◽  
...  
Keyword(s):  
Microarray Analysis ◽  
Copy Number ◽  
Copy Number Variations ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis

Chromosomal Microarray Analysis in Taiwanese Patients with Williams-Beuren Syndrome

2019 ◽  
Vol 159 (4) ◽  
pp. 182-189
Author(s):  
Haung-Tsung Kuo ◽  
Chieh-Ho Chen ◽  
Chien-Yu Lin ◽  
Ya-Sian Chang ◽  
Jan-Gowth Chang
Keyword(s):  
Microarray Analysis ◽  
Copy Number ◽  
Neurodevelopmental Disorder ◽  
Copy Number Variations ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Taiwanese Population ◽  
Gene Deletions ◽  
Wide Mouth ◽  
Break Points

Williams-Beuren Syndrome (WBS; OMIM #194050) is a rare neurodevelopmental disorder that results from a deletion at 7q11.23 spanning 25-27 genes. We performed chromosomal microarray analysis (CMA) in 9 Taiwanese patients with WBS to confirm the diagnosis. These samples had already been examined by FISH and diagnosed as WBS. Pathogenic copy number variations (CNVs) were identified in all patients, including 24 genes (spanning from FKBP6 to GTF2I) with typical 7q11.23 microdeletion. A deletion in TRIM50 was common in Taiwanese patients with WBS (8/9). Furthermore, 1 patient had 2 additional gene deletions in NCF1 and GTF2IRD2. We also found 4 patients with duplications of 4p16.1, 16p13.11, 10q26.3, and 21q22.3. All 9 WBS patients exhibited distinctive facial dysmorphisms, including a wide mouth, thick prominent lips, short nose with anteverted nares, and periorbital puffiness. However, cardiac defects were not frequent in our patients (3/9). In conclusion, we detected CNVs associated with WBS in a Taiwanese population using CMA. Although CMA is expensive and labor-intensive, it is useful for identifying typical/atypical CNVs, delineating distal break points, and detecting other CNVs.

X-linked CNV and skewed X-chromosome inactivation

2020 ◽  
pp. 19-21
Author(s):  
Е.А. Фонова ◽  
Е.Н. Толмачева ◽  
А.А. Кашеварова ◽  
М.Е. Лопаткина ◽  
К.А. Павлова ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Intellectual Disability ◽  
X Chromosome ◽  
Copy Number ◽  
Copy Number Variations ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Chromosome X ◽  
Skewed X Chromosome Inactivation

Смещение инактивации Х-хромосомы может быть следствием и маркером нарушения клеточной пролиферации при вариациях числа копий ДНК на Х-хромосоме. Х-сцепленные CNV выявляются как у женщин с невынашиванием беременности и смещением инактивации Х-хромосомы (с частотой 33,3%), так и у пациентов с умственной отсталостью и смещением инактивацией у их матерей (с частотой 40%). A skewed X-chromosome inactivation can be a consequence and a marker of impaired cell proliferation in the presence of copy number variations (CNV) on the X chromosome. X-linked CNVs are detected in women with miscarriages and a skewed X-chromosome inactivation (with a frequency of 33.3%), as well as in patients with intellectual disability and skewed X-chromosome inactivation in their mothers (with a frequency of 40%).

scholarly journals A Case With 4 de Novo Copy Number Variations With Clinical Features That Overlap 1q43q44 Microdeletion and 3q29 Microduplication Syndromes

2018 ◽  
Vol 5 ◽  
pp. 2329048X1879820
Author(s):  
Miriam Kessi ◽  
Jing Peng ◽  
Lifen Yang ◽  
Haolin Duan ◽  
Yulin Tang ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Corpus Callosum ◽  
Copy Number ◽  
De Novo ◽  
Copy Number Variations ◽  
Language Delay ◽  
Global Developmental Delay ◽  
Recurrent Infections ◽  
Dental Anomalies ◽  
Microdeletion Syndrome

1q43q44 microdeletion syndrome is characterized by intellectual disability/global developmental delay, epilepsy, dysmorphic facies, stereotypic movement, language delay, recurrent infections, dental anomalies, and hand and foot anomalies. Microcephaly and corpus callosum dysplasia are present in some cases depending on gene content. 3q29 microduplication syndrome is characterized by intellectual disability, language delay, microcephaly, and dental anomalies. We report the first case with 4 de novo copy number variations with clinical features which overlap 1q43q44 microdeletion and 3q29 microduplication syndromes. Our case presented with global developmental delay, epilepsy, recurrent infections, stereotypic movements, speech delay, microcephaly, facial dysmorphism, bilateral clinodactyly, and small puffy feet with metatarsus varus; however, she had no corpus callosum dysplasia. Our case highlights the role of multiple copy number variations in the occurrence of a certain phenotype. Moreover, it supports the theory that the loss of HNRNPU gene function cannot explain the occurrence of microcephaly and abnormalities of the corpus callosum in 1q43q44 microdeletion syndrome.

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