Mucolipidosis type II (MLII, MIM 252500) is a lysosomal storage disorders caused by defects in GNPTAB gene which encodes alpha and beta subunits of N-acetylglucosamine (GlcNAc)-1-phosphotransferase. Neonatal presentation includes coarse facial features, restricted postnatal growth, generalized hypotonia, gingival hypertrophy and multiple skeletal anomalies. Here we present a case of a 26-week gestational age preterm infant with MLII who did not exhibit the typical facial features at birth; however, the diagnosis was suggested from abnormal placental pathology showing trophoblastic lipidosis and initial skeletal abnormalities from chest radiograph revealing generalized diffuse severe bone demineralizing disease and multiple fractures. Biochemical testing revealed elevation of plasma lysosomal enzymes. Homozygous pathogenic variant, designated c.3505_3504del, was discovered from GNPTAB sequencing. Her course was complicated by respiratory distress, secondary hyperparathyroidism, abdominal distention and feeding difficulties. Urine mucopolysaccharides analysis revealed mild elevation of total and individual glycosaminoglycan species in a non-specific pattern. To our knowledge, our case is the most premature example of mucolipidosis type II that has ever been reported to date. This report highlights the importance of placental pathological studies in the diagnosis of lysosomal storage disorders.

II型粘膜脂肪病（MLII，MIM 252500）是一种溶酶体贮积病，由GNPTAB基因的缺陷引起，该基因编码N的α和β亚基-乙酰基葡糖胺（GlcNAc）-1-磷酸转移酶。新生儿表现包括五官粗糙，产后发育受限，肌张力低下，牙龈肥大和多发骨骼异常。在这里，我们介绍了一个26周胎龄早产儿MLII，在出生时没有表现出典型的面部特征的情况。然而，诊断是从胎盘病理异常显示滋养细胞脂质增生和胸部X线检查显示最初的骨骼异常，提示广泛性弥漫性严重的骨骼脱盐疾病和多处骨折的诊断。生化测试显示血浆溶酶体酶升高。从GNPTAB中发现了纯合的致病变体，命名为c.3505_3504del。排序。她的病程并发呼吸窘迫，继发性甲状旁腺功能亢进，腹胀和进食困难。尿液中的黏多糖分析显示，非特异性模式的总糖胺聚糖和单个糖胺聚糖的含量均呈轻度升高。据我们所知，我们的病例是迄今为止报道过的II型粘膜脂溢性病的最早的例子。该报告强调了胎盘病理学研究在溶酶体贮积病诊断中的重要性。