From the Departments of Radiology (J.-A.P.M., K.P.)
Clinical Genetics (M.W.).
AJNR Am J Neuroradiol. 2020 Jun;41(6):1087-1093. doi: 10.3174/ajnr.A6541. Epub 2020 May 14.
X-linked deafness-2 (DFNX2) is an X-linked recessive disorder characterized by profound sensorineural hearing loss and a pathognomonic temporal bone deformity. Because hypothalamic malformations associated with DFNX2 have been rarely described, we aimed to further describe these lesions and compare them with features of a nonaffected population. All patients diagnosed with DFNX2 between 2006 and 2019 were included and compared with age-matched patients with normal MR imaging findings and without hypothalamic dysfunction. MR imaging features differing between groups were selected to help identify DFNX2. Sensitivity and specificity were calculated for these features. Agreement among 3 radiologists was quantified using the index κ. Information on the presence or absence of gelastic seizures, precocious puberty, or delayed puberty was also gathered. We selected distinctive MR imaging features of hypothalamic malformations in DFNX2. The feature selected on axial T2 images was the folded appearance of the ventromedial hypothalamus (sensitivity, 100%; specificity, 95.8%) characterized by an abnormal internal/external cleft (sensitivity, 100%; specificity, 95.7%). On coronal T2, the first distinctive feature was a concave morphology of the medial eminence (sensitivity, 100%; specificity, 97.1%), the second feature was at least 1 hypothalamic-septum angle ≥90° (sensitivity, 90%; specificity, 72.5%), and the third feature was a forebrain-hypothalamic craniocaudal length of ≥6 mm (sensitivity, 70%; specificity, 79.7%). Clinical features were also distinctive because 9 patients with DFNX2 did not present with gelastic seizures or precocious puberty. One patient had delayed puberty. The κ index and intraclass correlation coefficient ranged between 0.78 and 0.95. Imaging and clinical features of the hypothalamus suggest that there is a hypothalamic malformation associated with DFNX2. Early assessment for pubertal delay is proposed.
X 连锁耳聋 2 型（DFNX2）是一种 X 连锁隐性疾病，其特征是严重的感觉神经性听力损失和典型的颞骨畸形。由于与 DFNX2 相关的下丘脑畸形很少被描述，我们旨在进一步描述这些病变，并将其与非受影响人群的特征进行比较。所有在 2006 年至 2019 年间被诊断为 DFNX2 的患者均被纳入研究，并与年龄匹配、磁共振成像结果正常且无下丘脑功能障碍的患者进行比较。选择两组之间存在差异的磁共振成像特征来帮助识别 DFNX2。计算这些特征的敏感性和特异性。使用指数κ来量化 3 位放射科医生之间的一致性。还收集了有无发笑性癫痫、性早熟或青春期延迟的信息。我们选择了 DFNX2 下丘脑畸形的独特磁共振成像特征。在轴位 T2 图像上选择的特征是腹内侧下丘脑的折叠外观（敏感性 100%，特异性 95.8%），其特征是异常的内/外裂（敏感性 100%，特异性 95.7%）。在冠状 T2 上，第一个独特的特征是内侧隆起的凹形形态（敏感性 100%，特异性 97.1%），第二个特征是至少 1 个下丘脑-隔角≥90°（敏感性 90%，特异性 72.5%），第三个特征是前脑-下丘脑颅尾长度≥6mm（敏感性 70%，特异性 79.7%）。临床特征也很独特，因为 9 名 DFNX2 患者没有出现发笑性癫痫或性早熟。1 名患者有青春期延迟。κ指数和组内相关系数在 0.78 至 0.95 之间。下丘脑的影像学和临床特征表明存在与 DFNX2 相关的下丘脑畸形。建议早期评估青春期延迟。
