Gray Matter Heterotopia, Mental Retardation, Developmental Delay, Microcephaly, and Facial Dysmorphisms in a Boy with Ring Chromosome 6: A 10-Year Follow-Up and Literature Review

2018 ◽  
Vol 154 (4) ◽  
pp. 201-208 ◽  
Author(s):  
Shu Liu ◽  
Zhiqing Wang ◽  
Sisi Wei ◽  
Jinqun Liang ◽  
Nuan Chen ◽  
...  

Ring chromosome 6, r(6), is an extremely rare cytogenetic abnormality with clinical heterogeneity which arises typically de novo. The phenotypes of r(6) can be highly variable, ranging from almost normal to severe malformations and neurological defects. Up to now, only 33 cases have been reported in the literature. In this 10-year follow-up study, we report a case presenting distinctive facial features, severe developmental delay, and gray matter heterotopia with r(6) and terminal deletions of 6p25.3 (115426-384174, 268 kb) and 6q26-27 (168697778-170732033, 2.03 Mb) encompassing 2 and 15 candidate genes, respectively, which were detected using G-banding karyotyping, FISH, and chromosomal microarray analysis. We also analyzed the available information on the clinical features of the reported r(6) cases in order to provide more valuable information on genotype-phenotype correlations. To the best of our knowledge, this is the first report of gray matter heterotopia manifested in a patient with r(6) in China, and the deletions of 6p and 6q in our case are the smallest with the precise size of euchromatic material loss currently known.

Author(s):  
М.Е. Миньженкова ◽  
Ж.Г. Маркова ◽  
И.В. Анисимова ◽  
И.В. Канивец ◽  
Н.В. Шилова

Выяснение этиопатогенеза аномального фенотипа у пациентов со сбалансированными транслокациями является актуальным аспектом в современной клинической цитогенетике. Формирование аномалий развития может быть ассоциировано с наличием скрытого геномного дисбаланса как в точках разрывов, так и на хромосомах, не задействованных в перестройке. Целью данного исследования явилась этиологическая диагностика геномного дисбаланса у пациента со сбалансированной транслокацией и аномалиями развития. Для детекции геномного дисбаланса у пациента со сбалансированной транслокацией использовали хромосомный микроматричный анализ (ХМА) и FISH-исследование. У пациента со сбалансированной транслокацией при ХМА была выявлена делеция на хромосоме 8, не задействованной в транслокации. Таким образом, в статье представлен новый случай делеции 8q22.2q22.3 у пациента со сбалансированной транслокацией t(1;6) и аномалиями развития вследствие делеции. Identification of the etiopathogenesis of the abnormal phenotype in patients with balanced translocations is current trend in cytogenetic laboratories. The formation of developmental anomalies can be associated with the presence of a cryptic genomic imbalance both at breakpoints and on chromosomes not involved in rearrangements.The aim of this study is diagnostics of genomic imbalance in a patient with balanced translocation and abnormal phenotype. The case was characterized by GTG-banding, chromosomal microarray analysis and FISH diagnosis. We present a new case of deletion 8q22.2-q22.3 in child with balanced translocation t(1;6) and developmental delay/congenital defects due to deletion.


2016 ◽  
Vol 148 (2-3) ◽  
pp. 165-173 ◽  
Author(s):  
Aswini Sivasankaran ◽  
Murthy K. Kanakavalli ◽  
Deenadayalu Anuradha ◽  
Chandra R. Samuel ◽  
Lakshmi R. Kandukuri

Ring chromosomes have been described for all human chromosomes and are typically associated with physical and/or mental abnormalities resulting from a deletion of the terminal ends of both chromosome arms. This report describes the presence of a ring chromosome 9 in a 2-year-old male child associated with developmental delay. The proband manifested a severe phenotype comprising facial dysmorphism, congenital heart defects, and seizures. The child also exhibited multiple cell lines with mosaic patterns of double rings, a dicentric ring and loss of the ring associated with mitotic instability and dynamic tissue-specific mosaicism. His karyotype was 46,XY,r(9)(p22q34)[89]/46,XY,dic r(9; 9)(p22q34;p22q34)[6]/45, XY,-9[4]/47,XY,r(9),+r(9)[1]. However, the karyotypes of his parents and elder brother were normal. FISH using mBAND probe and subtelomeric probes specific for p and q arms for chromosome 9 showed no deletion in any of the regions. Chromosomal microarray analysis led to the identification of a heterozygous deletion of 15.7 Mb from 9p22.3 to 9p24.3. The probable role of the deleted genes in the manifestation of the phenotype of the proband is discussed.


2018 ◽  
Vol 08 (01) ◽  
pp. 001-009
Author(s):  
Pinar Arican ◽  
Berk Ozyilmaz ◽  
Dilek Cavusoglu ◽  
Pinar Gencpinar ◽  
Kadri Erdogan ◽  
...  

AbstractChromosomal microarray (CMA) analysis for discovery of copy number variants (CNVs) is now recommended as a first-line diagnostic tool in patients with unexplained developmental delay/intellectual disability (DD/ID) and autism spectrum disorders. In this study, we present the results of CMA analysis in patients with DD/ID. Of 210 patients, pathogenic CNVs were detected in 26 (12%) and variants of uncertain clinical significance in 36 (17%) children. The diagnosis of well-recognized genetic syndromes was achieved in 12 patients. CMA analysis revealed pathogenic de novo CNVs, such as 11p13 duplication with new clinical features. Our results support the utility of CMA as a routine diagnostic test for unexplained DD/ID.


2008 ◽  
Vol 146A (7) ◽  
pp. 925-929 ◽  
Author(s):  
Martina Höckner ◽  
Barbara Utermann ◽  
Martin Erdel ◽  
Christine Fauth ◽  
Gerd Utermann ◽  
...  

Open Medicine ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 1123-1127
Author(s):  
Shuang Chen ◽  
Yang Yu ◽  
Han Zhang ◽  
Leilei Li ◽  
Yuting Jiang ◽  
...  

AbstractChromosomal microdeletions and microduplications likely represent the main genetic etiologies for children with developmental delay or intellectual disability. Through prenatal chromosomal microarray analysis, some microdeletions or microduplications can be detected before birth to avoid unnecessary abortions or birth defects. Although some microdeletions or microduplications of chromosome 5 have been reported, numerous microduplications remain undescribed. We describe herein a case of a 30-year-old woman carrying a fetus with a chromosome 5q21.1–q21.3 microduplication. Because noninvasive prenatal testing indicated a fetal chromosome 5 abnormality, the patient underwent amniocentesis at 22 weeks 4 days of gestation. Karyotyping and chromosomal microarray analysis were performed on amniotic fluid cells. Fetal behavioral and structural abnormalities were assessed by color and pulsed Doppler ultrasound. Clinical characteristics of the newborn were assessed during the follow-up. The left lateral ventricle appeared widened on ultrasound, but the infant appeared normal at birth. The 5q21.1–q21.3 microduplication in the fetus was inherited from his mother. There are seven genes in this duplication region, but their main functions are unclear. According to this case report, microduplication in this region could represent a benign mutation. Clinicians should pay attention to the breakpoints and the genes involved when counseling patients with microdeletions and microduplications.


1988 ◽  
Vol 34 (2) ◽  
pp. 273-276 ◽  
Author(s):  
Stephen J. Russell ◽  
Helen Walker ◽  
Francis J. Giles ◽  
Anthony H. Goldstone

2021 ◽  
Vol 12 ◽  
Author(s):  
Sha Liu ◽  
Hongqian Liu ◽  
Jianlong Liu ◽  
Ting Bai ◽  
Xiaosha Jing ◽  
...  

BackgroundOur aim was to provide a theoretical basis for clinicians to conduct genetic counseling and choose further prenatal diagnosis methods for pregnant women who failed non-invasive prenatal screening (NIPS).MethodsA retrospective analysis was performed on pregnant women who had failed NIPS tests.ResultsAmong the 123,291 samples, 394 pregnant women did not obtain valid results due to test failures. A total of 378 pregnant women were available for follow-up, while 16 patients were lost to follow-up. Of these 378, 135 pregnant women chose further prenatal diagnosis through amniocentesis, and one case of dysplasia was recalled for postpartum chromosome testing. The incidence rate of congenital chromosomal abnormalities in those who failed the NIPS was 3.97% (15/378), which was higher than that of the chromosomal abnormalities in the common population (1.8%). Among the pregnant women who received prenatal diagnosis, the positive rates of chromosomal abnormalities in the chromosomal microarray analysis/copy number variation sequencing (CMA/CNV-seq) group and in the karyotyping group were 15.28 and 4.76%, respectively.ConclusionPrenatal diagnosis should be strongly recommended in posttest genetic counseling for pregnant women with NIPS failures. Further, high-resolution detection methods should be recommended for additional prenatal diagnoses.


2020 ◽  
Author(s):  
Abul Kalam Azad ◽  
Lindsay Yanakakis ◽  
Samantha Issleb ◽  
Jessica Turina ◽  
Kelli Drabik ◽  
...  

Abstract Background Full or partial monosomy of chromosome (chr) 21 is a very rare abnormal cytogenetic finding. It is characterized by variable sizes and deletion breakpoints on the long arm (q) of chr 21 that lead to a broad spectrum of phenotypes that include an increased risk of birth defects, developmental delay and intellectual deficit. Case presentation: We report a 37-year-old G1P0 woman initially screened by non-invasive prenatal testing with no positive findings that was followed by an 18-week anatomy scan with a fetal finding of duplication of the superior vena cava (SVC). The medical and family history was otherwise uneventful. After appropriate genetic counseling, amniocentesis was performed to evaluate suspected chromosomal anomalies. Conclusions Fluorescent in situ hybridization revealed loss of one chr 21 signal that was further delineated by chromosomal microarray analysis on uncultured amniocytes as a terminal 10 Mb deletion on chr 21q. Karyotype and microarrays on cultured amniocytes showed two cell lines for a mosaic 21q terminal deletion and monosomy 21. The combined molecular cytogenetics results reported as mos 45,XX,-21[10]/46,XX,del(21)(q22)dn[20].nuc ish(D21S342/D21S341/D21S259 × 1)[100].arr[GRCh37] 21q11.2q22.12(15412676_36272993)x1 ~ 2,21q22.12q22.3(36431283_47612400)x1. Parental chromosomal analysis revealed normal karyotypes. Thus, this was a de novo mosaic full and partial monosomy of chr 21 in a case with SVC duplication. Despite the association of congenital heart disease with monsomy 21 we could not find any published literature or online databases for this cytogenetic abnormality. The patient terminated the pregnancy following the abnormal molecular cytogenetic results due to the possible challenges the baby would face if carried to term.


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