Cases of 2q23q24 microdeletion syndrome are rare. Patients with chromosomal deletions in this region often show language impairment and/or developmental delay of variable severity. Previous genotype–phenotype correlation study suggested GALNT13 and KCNJ3 as possible candidate genes for such phenotypes. We identified a new overlapping deletion in a patient with severe developmental delay. The identified deletion extended toward the distal 2q24.1 region, and more severe phenotypes in the present patient were considered to be related to the additionally deleted genes including NR4A2 and GPD2. Previously reported chromosomal translocation and the mutation identified in GPD2 suggested that this gene would be responsible for the developmental delay. Re‐evaluation for the critical region for behavior abnormalities commonly observed in the patients with overlapping deletions of this region suggested that KCNJ3 rather than GALNT13 may be responsible for abnormal behaviors, although there was phenotypic variability. Combinatory deletions involving KCNJ3 and GPD2 may lead to more severe developmental delay. Further studies would be necessary to establish clearer genotype–phenotype correlation in patients with 2q23q24 microdeletion syndrome.
{"title":"Possible genes responsible for developmental delay observed in patients with rare 2q23q24 microdeletion syndrome: Literature review and description of an additional patient","authors":"K. Shimojima, N. Okamoto, Toshiyuki Yamamoto","doi":"10.1111/cga.12205","DOIUrl":"https://doi.org/10.1111/cga.12205","url":null,"abstract":"Cases of 2q23q24 microdeletion syndrome are rare. Patients with chromosomal deletions in this region often show language impairment and/or developmental delay of variable severity. Previous genotype–phenotype correlation study suggested GALNT13 and KCNJ3 as possible candidate genes for such phenotypes. We identified a new overlapping deletion in a patient with severe developmental delay. The identified deletion extended toward the distal 2q24.1 region, and more severe phenotypes in the present patient were considered to be related to the additionally deleted genes including NR4A2 and GPD2. Previously reported chromosomal translocation and the mutation identified in GPD2 suggested that this gene would be responsible for the developmental delay. Re‐evaluation for the critical region for behavior abnormalities commonly observed in the patients with overlapping deletions of this region suggested that KCNJ3 rather than GALNT13 may be responsible for abnormal behaviors, although there was phenotypic variability. Combinatory deletions involving KCNJ3 and GPD2 may lead to more severe developmental delay. Further studies would be necessary to establish clearer genotype–phenotype correlation in patients with 2q23q24 microdeletion syndrome.","PeriodicalId":93953,"journal":{"name":"Congenital anomalies","volume":"51 1","pages":"109 - 113"},"PeriodicalIF":0.0,"publicationDate":"2017-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89571684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hironobu Okuno, K. Nakabayashi, K. Abe, Takayuki Ando, Tsukasa Sanosaka, J. Kohyama, W. Akamatsu, M. Ohyama, Takao Takahashi, K. Kosaki, H. Okano
Prader‐Will syndrome (PWS) is characterized by hyperphagia, growth hormone deficiency and central hypogonadism caused by the dysfunction of the hypothalamus. Patients with PWS present with methylation abnormalities of the PWS‐imprinting control region in chromosome 15q11.2, subject to parent‐of‐origin‐specific methylation and controlling the parent‐of‐origin‐specific expression of other paternally expressed genes flanking the region. In theory, the reversal of hypermethylation in the hypothalamic cells could be a promising strategy for the treatment of PWS patients, since cardinal symptoms of PWS patients are correlated with dysfunction of the hypothalamus. The genome‐wide methylation status dramatically changes during the reprograming of somatic cells into induced pluripotent stem cells (iPSCs) and during the in vitro culture of iPSCs. Here, we tested the methylation status of the chromosome 15q11.2 region in iPSCs from a PWS patient using pyrosequencing and a more detailed method of genome‐wide DNA methylation profiling to reveal whether iPSCs with a partially unmethylated status for the chromosome 15q11.2 region exhibit global methylation aberrations. As a result, we were able to show that a fully methylated status for chromosome 15q11.2 in a PWS patient could be reversed to a partially unmethylated status in at least some of the PWS‐iPSC lines. Genome‐wide DNA methylation profiling revealed that the partial unmethylation occurred at differentially methylated regions located in chromosome 15q11.2, but not at other differentially methylated regions associated with genome imprinting. The present data potentially opens a door to cell‐based therapy for PWS patients and, possibly, patients with other disorders associated with genomic imprinting.
{"title":"Changeability of the fully methylated status of the 15q11.2 region in induced pluripotent stem cells derived from a patient with Prader‐Willi syndrome","authors":"Hironobu Okuno, K. Nakabayashi, K. Abe, Takayuki Ando, Tsukasa Sanosaka, J. Kohyama, W. Akamatsu, M. Ohyama, Takao Takahashi, K. Kosaki, H. Okano","doi":"10.1111/cga.12206","DOIUrl":"https://doi.org/10.1111/cga.12206","url":null,"abstract":"Prader‐Will syndrome (PWS) is characterized by hyperphagia, growth hormone deficiency and central hypogonadism caused by the dysfunction of the hypothalamus. Patients with PWS present with methylation abnormalities of the PWS‐imprinting control region in chromosome 15q11.2, subject to parent‐of‐origin‐specific methylation and controlling the parent‐of‐origin‐specific expression of other paternally expressed genes flanking the region. In theory, the reversal of hypermethylation in the hypothalamic cells could be a promising strategy for the treatment of PWS patients, since cardinal symptoms of PWS patients are correlated with dysfunction of the hypothalamus. The genome‐wide methylation status dramatically changes during the reprograming of somatic cells into induced pluripotent stem cells (iPSCs) and during the in vitro culture of iPSCs. Here, we tested the methylation status of the chromosome 15q11.2 region in iPSCs from a PWS patient using pyrosequencing and a more detailed method of genome‐wide DNA methylation profiling to reveal whether iPSCs with a partially unmethylated status for the chromosome 15q11.2 region exhibit global methylation aberrations. As a result, we were able to show that a fully methylated status for chromosome 15q11.2 in a PWS patient could be reversed to a partially unmethylated status in at least some of the PWS‐iPSC lines. Genome‐wide DNA methylation profiling revealed that the partial unmethylation occurred at differentially methylated regions located in chromosome 15q11.2, but not at other differentially methylated regions associated with genome imprinting. The present data potentially opens a door to cell‐based therapy for PWS patients and, possibly, patients with other disorders associated with genomic imprinting.","PeriodicalId":93953,"journal":{"name":"Congenital anomalies","volume":"130 1","pages":"103 - 96"},"PeriodicalIF":0.0,"publicationDate":"2017-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75037440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Sawada, K. Fukunishi, M. Kashima, Noritaka Imai, S. Saito, I. Aoki, Y. Fukui
The present study aimed to specify the cerebral sulci developed by cortical expansion in cynomolgus monkey fetuses. The degree of sulcal infolding was evaluated by the gyrification index (GI), which was quantified using ex vivo magnetic resonance imaging. The correlation of cortical volume with the sulcal GI was most frequent during embryonic days (EDs) 100 to 120. Interestingly, the high correlation was marked during EDs 140 to 150 in restricted primary sulci in prefrontal, parietotemporal and medial temporal regions. The present results suggest that cortical expansion is involved in gyral demarcation by sulcal infolding, followed by the sulcal infolding progression in phylogenetically‐newer cortices.
{"title":"Regional difference in sulcal infolding progression correlated with cerebral cortical expansion in cynomolgus monkey fetuses","authors":"K. Sawada, K. Fukunishi, M. Kashima, Noritaka Imai, S. Saito, I. Aoki, Y. Fukui","doi":"10.1111/cga.12209","DOIUrl":"https://doi.org/10.1111/cga.12209","url":null,"abstract":"The present study aimed to specify the cerebral sulci developed by cortical expansion in cynomolgus monkey fetuses. The degree of sulcal infolding was evaluated by the gyrification index (GI), which was quantified using ex vivo magnetic resonance imaging. The correlation of cortical volume with the sulcal GI was most frequent during embryonic days (EDs) 100 to 120. Interestingly, the high correlation was marked during EDs 140 to 150 in restricted primary sulci in prefrontal, parietotemporal and medial temporal regions. The present results suggest that cortical expansion is involved in gyral demarcation by sulcal infolding, followed by the sulcal infolding progression in phylogenetically‐newer cortices.","PeriodicalId":93953,"journal":{"name":"Congenital anomalies","volume":"12 1","pages":"114 - 117"},"PeriodicalIF":0.0,"publicationDate":"2017-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81902140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Takakuwa, Teppei Koike, Taiga Muranaka, C. Uwabe, S. Yamada
The circle of Willis (CW) is a circulatory anastomosis that supplies blood to the brain and adjacent structures. We examined the timing of formation of CW in 20 Japanese human embryo samples by using 3‐dimensional reconstruction of serial histological sections. The CW was closed in 1 (n = 6), 2 (n = 8), 2 (n = 3) and 2 (n = 3) samples at Carnegie stages 20, 21, 22, and 23, respectively. The CW was unclosed in 13 samples (unclosed at ACOM alone, 6 samples; ACOM and bilateral P1, 4; left PCOM and right P1, 1; right PCOM and right P1, 1; ACOM and left PCOM, 1). It was difficult to predict whether the circle would close during further development, as such variations frequently exist in adults.
{"title":"Formation of the circle of Willis during human embryonic development","authors":"T. Takakuwa, Teppei Koike, Taiga Muranaka, C. Uwabe, S. Yamada","doi":"10.1111/cga.12165","DOIUrl":"https://doi.org/10.1111/cga.12165","url":null,"abstract":"The circle of Willis (CW) is a circulatory anastomosis that supplies blood to the brain and adjacent structures. We examined the timing of formation of CW in 20 Japanese human embryo samples by using 3‐dimensional reconstruction of serial histological sections. The CW was closed in 1 (n = 6), 2 (n = 8), 2 (n = 3) and 2 (n = 3) samples at Carnegie stages 20, 21, 22, and 23, respectively. The CW was unclosed in 13 samples (unclosed at ACOM alone, 6 samples; ACOM and bilateral P1, 4; left PCOM and right P1, 1; right PCOM and right P1, 1; ACOM and left PCOM, 1). It was difficult to predict whether the circle would close during further development, as such variations frequently exist in adults.","PeriodicalId":93953,"journal":{"name":"Congenital anomalies","volume":"53 1","pages":"233 - 236"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89820144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ying Xiang, Jingxia Bian, Zhigang Wang, Yunlan Xu, Q. Fu
Polydactyly is one of the most common hereditary limb malformations, involving additional digits on the hands and/or feet, which is a very attractive model to appreciate clinical and genetic heterogeneity. A high level of heterogeneity in polydactyly has been identified in different regions. However, such data of the medical literatures for Asian populations are relatively limited. This study was intended to shed light on the phenotypic manifestations of polydactyly in the recruited Chinese population and to characterize the medical literature on this condition. A total of 459 well‐characterized polydactyly cases from Shanghai Children's Medical Center were recruited. Their phenotypes, inheritance patterns, and clinical heterogeneity were obtained from clinical medical records. It was found that 4.8% of cases were familial and 95.2% were sporadic. The proportions of preaxial and postaxial polydactyly types were 74.7% and 25.3%, respectively. In preaxial polydactyly, type I formed the overwhelming majority (95.9%). Among the postaxial polydactyly cases, type A was most prevalent at 69.8% and type B was witnessed in 30.2% of cases. Familial and sporadic polydactyly patients mainly had unilateral presentations. A total of 583 limbs with additional digits were recorded in the 459 subjects. Upper limb involvement was more common than lower, and right hand involvement was more common than left for preaxial polydactyly, and lower limb involvement was more common than upper in postaxial polydactyly. This cohort added useful clinical/epidemiological information to the polydactyly literature in the Chinese population and highlighted its marked clinical heterogeneity.
{"title":"Clinical study of 459 polydactyly cases in China, 2010 to 2014","authors":"Ying Xiang, Jingxia Bian, Zhigang Wang, Yunlan Xu, Q. Fu","doi":"10.1111/cga.12163","DOIUrl":"https://doi.org/10.1111/cga.12163","url":null,"abstract":"Polydactyly is one of the most common hereditary limb malformations, involving additional digits on the hands and/or feet, which is a very attractive model to appreciate clinical and genetic heterogeneity. A high level of heterogeneity in polydactyly has been identified in different regions. However, such data of the medical literatures for Asian populations are relatively limited. This study was intended to shed light on the phenotypic manifestations of polydactyly in the recruited Chinese population and to characterize the medical literature on this condition. A total of 459 well‐characterized polydactyly cases from Shanghai Children's Medical Center were recruited. Their phenotypes, inheritance patterns, and clinical heterogeneity were obtained from clinical medical records. It was found that 4.8% of cases were familial and 95.2% were sporadic. The proportions of preaxial and postaxial polydactyly types were 74.7% and 25.3%, respectively. In preaxial polydactyly, type I formed the overwhelming majority (95.9%). Among the postaxial polydactyly cases, type A was most prevalent at 69.8% and type B was witnessed in 30.2% of cases. Familial and sporadic polydactyly patients mainly had unilateral presentations. A total of 583 limbs with additional digits were recorded in the 459 subjects. Upper limb involvement was more common than lower, and right hand involvement was more common than left for preaxial polydactyly, and lower limb involvement was more common than upper in postaxial polydactyly. This cohort added useful clinical/epidemiological information to the polydactyly literature in the Chinese population and highlighted its marked clinical heterogeneity.","PeriodicalId":93953,"journal":{"name":"Congenital anomalies","volume":"30 1","pages":"226 - 232"},"PeriodicalIF":0.0,"publicationDate":"2016-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91351190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Do Hyung Lee, Bo-Kyung Je, Doran Hong, Sang-Dae Kim, S. Eun
Occipital condylar dysplasia is a rare congenital anomaly that is caused by failure to form lateral elements of the 4 occipital sclerotome from the 4 week of gestation (Tubbs et al. 2013). This flattened and underdeveloped condyle occurs as an isolated anomaly or as part of complex Atlanto-occipital abnormality (Shapiro and Robinson 1976). Although its clinical manifestations are headache, stiff neck, torticollis, ataxia, and neurological signs associated with cervicomedullary compression, this congenital anomaly is difficult to be recognized, due to late onset of symptoms that usually occurs no sooner than the second decades (Kruyff 1965; Shapiro and Robinson 1976). Therefore, imaging examination is mandatory for its diagnosis. A 6-year-old girl underwent brain magnetic resonance imaging (MRI) to evaluate a recent episode of lateral deviation of the left eyeball. Contrast-enhanced brain MR images showed displaced medulla oblongata and upper cervical cord by a bony protrusion into the foramen magnum (Fig. 1a,b). Multidetector computed tomography (CT) with three-dimensional reconstruction revealed that the left occipital condyle is asymmetrically small as compared with the right one, so the craniovertebral junction (CVJ) was tilted with the SchmidtFisher angle of 130° which is no more than 125° in normal CVJ. The bony protrusion on MR was the medial part of the left occipital condyle, which was due to the pressure by atlas, leading to displaced medulla, tilting of atlas and axis, and atlanto-axial subluxation (Fig. 1c–e). Due to the tilting atlas, the course of the left vertebral artery and the canal for the left hypoglossal nerve were aberrant and elongated, as compared with the normal contralateral ones (Fig. 1f). Considering the lateral displacement of brainstem and cervical cord, we are planning an operation to decompress the deformity in order to prevent cord compression and attain stability of CVJ. Craniovertebral junction is comprised of occiput, atlas, axis, and supporting ligaments (Smoker 1994). Anatomically, this articulation surrounds the cervicomedullary junction, including medulla oblongata, spinal cord, and lower cranial nerves (Smoker 1994; Tubbs et al. 2013). Functionally, CVJ keeps movement of the head on the neck and the stability of the vertebrae, thus protecting the spinal cord (David et al. 1998). As a part of CVJ, occipital condyles articulate with the superior faces of the atlas to form the atlanto-occipital joints that contribute to the flexion and extension of the head and neck (Tubbs et al. 2013). Thus, occipital condylar hypoplasia can lead to instability of CVJ and compression of the cervicomedullary junction as well as adjacent vascular structures, resulting in various neurological disorders such as ataxia, spastic quadriparesis and lower cranial nerve palsies (Kruyff 1965). However, symptoms usually begin insidiously and generally occur near adolescence when the axial growth is accelerated (Ryken & Menezes, 1993). In
枕髁发育不良是一种罕见的先天性异常，其原因是在妊娠4周后未能形成枕骨4侧硬膜(Tubbs et al. 2013)。这种扁平和不发达的髁是孤立的异常或复杂的寰枕异常的一部分(Shapiro和Robinson 1976)。虽然其临床表现为头痛、颈部僵硬、斜颈、共济失调和与颈髓受压相关的神经学症状，但由于症状发作较晚，通常不早于20岁，因此这种先天性异常很难识别(Kruyff 1965;夏皮罗和罗宾逊1976)。因此，影像学检查是诊断的必要手段。一个6岁的女孩接受了脑磁共振成像(MRI)来评估最近发生的左眼球外侧偏。增强的脑MR图像显示延髓和上颈髓因骨突进入枕骨大孔而移位(图1a,b)。多层CT三维重建显示，左枕髁相对于右枕髁不对称小，导致颅椎交界处(CVJ)倾斜，schmidt - fisher角为130°，正常CVJ不大于125°。MR上的骨突出是左枕髁内侧，这是由于寰椎的压力，导致髓质移位，寰椎和轴倾斜，寰枢半脱位(图1c-e)。由于寰椎倾斜，与正常对侧相比，左侧椎动脉和左侧舌下神经管的走行异常且延长(图1f)。考虑到脑干和颈髓的外侧移位，我们计划对畸形进行减压手术，以防止脊髓受压，实现CVJ的稳定。颅椎交界处由枕骨、寰椎、椎轴和支持韧带组成(Smoker 1994)。解剖上，该关节围绕颈髓连接处，包括延髓、脊髓和下颅神经(Smoker 1994;Tubbs et al. 2013)。在功能上，CVJ保持头部在颈部的运动和椎骨的稳定，从而保护脊髓(David et al. 1998)。作为CVJ的一部分，枕髁与寰椎的上面连接形成寰枕关节，有助于头部和颈部的屈伸(Tubbs et al. 2013)。因此，枕髁发育不全可导致CVJ不稳定，压迫颈髓交界处及邻近血管结构，导致各种神经系统疾病，如共济失调、痉挛性四肢瘫和下颅神经麻痹(Kruyff 1965)。然而，症状通常在不知不觉中开始，通常发生在青春期附近，此时轴向生长加速(Ryken & Menezes, 1993)。在我们的病例中，患者就诊的症状是左眼外侧偏。此外，她有发育迟缓，构音障碍，左腿障碍一段时间未被评估。然而，我们不能确定这些症状与枕髁异常引起的颈髓移位之间的任何关系。体检发现她患有轻微的斜颈，她的父母之前甚至没有注意到。我们的结论是，本病例的左枕髁发育不良是偶然发现的，与患者的癫痫发作、发育迟缓、构音障碍和跛腿无关。自1965年Kruyff首次引入枕骨发育不良的平片以来，CT被认为是评估CVJ关节和研究枕髁发育不良的最佳方式(Kruyff 1965;Ilkko et al. 1998)。目前，随着多探测器CT的广泛使用，我们可以获得最先进的CVJ三维图像，如图所示。此外，MR可以在多个正交平面上显示脑干、脊髓、下颅神经和韧带的详细特征。总之，枕髁发育不良是一种罕见的先天性异常，可以发生在CVJ作为一个孤立的异常或综合征的一部分。由于其症状多样且表现较晚，因此医生应了解CVJ先天性异常的影像学特征。三维CT和MR特征可以显示CVJ的详细关节。CVJ周围神经血管结构的可视化对手术计划至关重要。
{"title":"Unilateral occipital condylar dysplasia: 3‐dimensional multidetector computed tomography and magnetic resonance findings","authors":"Do Hyung Lee, Bo-Kyung Je, Doran Hong, Sang-Dae Kim, S. Eun","doi":"10.1111/cga.12160","DOIUrl":"https://doi.org/10.1111/cga.12160","url":null,"abstract":"Occipital condylar dysplasia is a rare congenital anomaly that is caused by failure to form lateral elements of the 4 occipital sclerotome from the 4 week of gestation (Tubbs et al. 2013). This flattened and underdeveloped condyle occurs as an isolated anomaly or as part of complex Atlanto-occipital abnormality (Shapiro and Robinson 1976). Although its clinical manifestations are headache, stiff neck, torticollis, ataxia, and neurological signs associated with cervicomedullary compression, this congenital anomaly is difficult to be recognized, due to late onset of symptoms that usually occurs no sooner than the second decades (Kruyff 1965; Shapiro and Robinson 1976). Therefore, imaging examination is mandatory for its diagnosis. A 6-year-old girl underwent brain magnetic resonance imaging (MRI) to evaluate a recent episode of lateral deviation of the left eyeball. Contrast-enhanced brain MR images showed displaced medulla oblongata and upper cervical cord by a bony protrusion into the foramen magnum (Fig. 1a,b). Multidetector computed tomography (CT) with three-dimensional reconstruction revealed that the left occipital condyle is asymmetrically small as compared with the right one, so the craniovertebral junction (CVJ) was tilted with the SchmidtFisher angle of 130° which is no more than 125° in normal CVJ. The bony protrusion on MR was the medial part of the left occipital condyle, which was due to the pressure by atlas, leading to displaced medulla, tilting of atlas and axis, and atlanto-axial subluxation (Fig. 1c–e). Due to the tilting atlas, the course of the left vertebral artery and the canal for the left hypoglossal nerve were aberrant and elongated, as compared with the normal contralateral ones (Fig. 1f). Considering the lateral displacement of brainstem and cervical cord, we are planning an operation to decompress the deformity in order to prevent cord compression and attain stability of CVJ. Craniovertebral junction is comprised of occiput, atlas, axis, and supporting ligaments (Smoker 1994). Anatomically, this articulation surrounds the cervicomedullary junction, including medulla oblongata, spinal cord, and lower cranial nerves (Smoker 1994; Tubbs et al. 2013). Functionally, CVJ keeps movement of the head on the neck and the stability of the vertebrae, thus protecting the spinal cord (David et al. 1998). As a part of CVJ, occipital condyles articulate with the superior faces of the atlas to form the atlanto-occipital joints that contribute to the flexion and extension of the head and neck (Tubbs et al. 2013). Thus, occipital condylar hypoplasia can lead to instability of CVJ and compression of the cervicomedullary junction as well as adjacent vascular structures, resulting in various neurological disorders such as ataxia, spastic quadriparesis and lower cranial nerve palsies (Kruyff 1965). However, symptoms usually begin insidiously and generally occur near adolescence when the axial growth is accelerated (Ryken & Menezes, 1993). In","PeriodicalId":93953,"journal":{"name":"Congenital anomalies","volume":"68 1","pages":"243 - 244"},"PeriodicalIF":0.0,"publicationDate":"2016-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91534214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-03-01DOI: 10.1142/S0578563405001185
.•'l tJ7SCE, B. Choi, Marjolein Dohmen-Janssen, T. Hiraishi, F. Imamura, Nobuhisa Kobayashi, Haruyuki Kojima, Shoichiro Kojima, Toshimitsu Komatsu, Jeffrey A. Melby, Kazuo Murakami, T. Ohyama, A. Okayasu, T. Shibayama, T. Shigematsu, S. Suh, Tomoyuki Takahashi, K. Takikawa, Hitoshi Tanaka
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