Petrak Borivoj, Kraus Josef, Bendova Sarka, Dvorakova Marcela, Pourova Radka Kremlikova, Ebel Matyas, Glombova Marie, Jakoubek Vit, Musova Zuzana, Hedvicakova Petra, Santova Alzbeta, Maminak Miroslav, Tesner Pavel
Second Faculty of Medicine, Department of Paediatric Neurology, Charles University and Motol University Hospital, Prague, Czech Republic.
Second Faculty of Medicine, Department of Paediatric Neurology, Charles University and Motol University Hospital, Prague, Czech Republic.
Pediatr Neurol. 2025 Aug;169:142-147. doi: 10.1016/j.pediatrneurol.2025.05.008. Epub 2025 May 12.
Legius syndrome (LGSS) is a rare neurocutaneous disorder that is differentiated from neurofibromatosis type I (NF1) based on pathogenic variants in the SPRED1 gene (15q14). Similar to NF1, LGSS also presents with café-au-lait macules on the skin and sometimes intertriginous freckling; however, the other diagnostic features of NF1 are absent in LGSS. Clinical contradistinction from NF1 is important for an LGSS diagnosis, but molecular genetic confirmation is necessary. Hypersignal areas on T2-weighted magnetic resonance imaging (MRI) (focal areas of signal intensity [FASI]) in specific brain locations are another common clinical finding in NF1. The aim of this study is to compare the incidence of FASI in LGSS and NF1 in an effort to further distinguish these two clinical entities and evaluate the clinical and diagnostic significance of an absence of FASI in LGSS.
We have examined a group of 16 children with LGSS and a group of 130 children with NF1. All children had been clinically and molecularly diagnosed with LGSS or NF1 and had had MRI examinations of their brains. FASI findings on these scans were evaluated. The independence of FASI on diagnosis was evaluated using the Fischer exact test.
FASI were found in 116 of 130 (89%) children with NF1, and no FASI was detected in children with LGSS (zero of 16, 0%). The presence of FASI was significantly dependent on the diagnosis.
We suggest that the absence of FASI on brain MRI examinations of patients with LGSS is an important clinical and diagnostic feature of this disorder.
勒吉尤斯综合征（LGSS）是一种罕见的神经皮肤疾病，基于SPRED1基因（15q14）的致病变异与1型神经纤维瘤病（NF1）相鉴别。与NF1相似，LGSS也表现为皮肤上的咖啡牛奶斑，有时还有间擦部位雀斑；然而，LGSS不存在NF1的其他诊断特征。与NF1进行临床鉴别对LGSS的诊断很重要，但分子遗传学确认是必要的。特定脑区在T2加权磁共振成像（MRI）上的高信号区（信号强度灶性区 [FASI]）是NF1的另一个常见临床发现。本研究的目的是比较LGSS和NF1中FASI的发生率，以进一步区分这两种临床实体，并评估LGSS中不存在FASI的临床和诊断意义。
我们检查了一组16名患有LGSS的儿童和一组130名患有NF1的儿童。所有儿童均已通过临床和分子诊断为LGSS或NF1，并对其脑部进行了MRI检查。对这些扫描结果中的FASI发现进行了评估。使用费舍尔精确检验评估FASI对诊断的独立性。
130名NF1儿童中有116名（89%）发现有FASI，而LGSS儿童中未检测到FASI（16名中0名，0%）。FASI的存在与诊断显著相关。
我们认为，LGSS患者脑部MRI检查未发现FASI是该疾病的一个重要临床和诊断特征。
