Benini Ruba, Saint-Martin Christine, Shevell Michael I, Bernard Genevieve
Division of Pediatric Neurology, McGill University, Montreal, Quebec, Canada.
J Child Neurol. 2012 Aug;27(8):1042-7. doi: 10.1177/0883073811430268. Epub 2012 Jan 30.
Partial deletion of genetic material from the long arm of chromosome 18 results in a syndrome with multisystemic involvement, including dysmorphic features, intellectual disability, cardiac malformations, endocrine abnormalities, immunodeficiency, musculoskeletal deformities, and variable neurologic manifestations. Hypomyelination has been reported in patients with chromosome 18q- and postulated to be secondary to deletion of the gene coding for myelin basic protein found at 18q23. Little however is reported on cerebral anomalies seen in patients with ring chromosome 18, an analogous syndrome but with expectedly more severe phenotype secondary to the combined deletions of genetic material from both the short (p-) and long arm (q-) of chromosome 18. We are reporting a case of a girl with ring chromosome 18 and deletions involving 18p11.32-18p11.21 and 18q21.31-18q23. The abnormalities observed on magnetic resonance imaging are discussed with a specific focus on the evolution and significance of associated white matter changes.
18号染色体长臂遗传物质的部分缺失会导致一种多系统受累的综合征，包括畸形特征、智力残疾、心脏畸形、内分泌异常、免疫缺陷、肌肉骨骼畸形以及各种神经系统表现。18q-患者中曾有髓鞘形成低下的报道，并推测这是由于位于18q23的髓鞘碱性蛋白编码基因缺失所致。然而，关于18号环状染色体患者中所见脑异常的报道很少，18号环状染色体是一种类似的综合征，但由于18号染色体短臂（p-）和长臂（q-）的遗传物质联合缺失，其表型预计更为严重。我们报告一例患有18号环状染色体且缺失涉及18p11.32 - 18p11.21和18q21.31 - 18q23的女孩病例。本文将讨论磁共振成像观察到的异常情况，并特别关注相关白质变化的演变及意义。
