Unlike the 1p36 microdeletion syndrome, which has been extensively described, 1p36.3 microduplications have rarely been reported. We report the two siblings of familial 1p36.3 microduplication, presenting with a severe global developmental delay, epilepsy, and a few dysmorphic features. They were referred to moderate-to-severe developmental delay (DD) and intellectual disability (ID). Both were considered eyelid myoclonus with absence of epilepsy (Jeavons syndrome). The EEG is characterized by widespread 2.5–3.5 Hz spikes and spike slow complex wave, eye closure sensitivity, and photosensitivity. The children has same dysmorphic features, including mild bitemporal narrowing and sloping forehead, sparse eyebrows, hypertelorism, ptosis, strabismus, infraorbital creases, wide nasal bridge with bulbous nasal tip, dystaxia, hallux valgus, and flat feet. Family exome sequencing revealed a maternally inherited 3.2-Mb microduplication of chromosomal band 1p36.3p36.2. However, DNA purified from blood samples of either parent did not find evidence for a microduplication of 1p36 in somatic tissue, indicating that such a mutation might be carried in the germline of the parents as gonadal mosaicism. No other family members of the affected siblings’ parents were reported to be affected by the symptoms found.

与已被广泛描述的 1p36 微缺失综合征不同，1p36.3 微重复很少有报道。我们报告了家族性 1p36.3 微重复的两个兄弟姐妹，表现出严重的整体发育迟缓、癫痫和一些畸形特征。他们被称为中度至重度发育迟缓（DD）和智力障碍（ID）。两者均被认为是眼睑肌阵挛，不伴有癫痫（杰文斯综合征）。EEG 的特点是广泛的 2.5-3.5 Hz 尖峰和尖峰慢复合波、闭眼敏感性和光敏感性。儿童具有相同的畸形特征，包括轻度双颞部狭窄和前额倾斜、眉毛稀疏、距离过远、上睑下垂、斜视、眶下皱纹、鼻梁宽且鼻尖呈球状、运动障碍、拇外翻和扁平足。家族外显子组测序显示，染色体带 1p36.3p36.2 存在母系遗传的 3.2 Mb 微重复。然而，从父母双方的血液样本中纯化的 DNA 并未发现体细胞组织中存在 1p36 微复制的证据，这表明这种突变可能以性腺嵌合的形式存在于父母的种系中。据报道，受影响兄弟姐妹的父母中没有其他家庭成员受到所发现症状的影响。