Wongkittichote Parith, Upchurch Garland Michael, Dehner Louis P, Wood Timothy, Granadillo Jorge L
Division of Genetics and Genomic Medicine, Department of Pediatrics, Washington University School of Medicine, St Louis, MO, United States of America.
Department of Pathology and Immunology (Lauren V. Ackerman Laboratory of Surgical Pathology), Washington University School of Medicine, St Louis, MO, United States of America.
Mol Genet Metab Rep. 2021 Mar 25;27:100747. doi: 10.1016/j.ymgmr.2021.100747. eCollection 2021 Jun.
Mucolipidosis type II (MLII, MIM 252500) is a lysosomal storage disorders caused by defects in gene which encodes alpha and beta subunits of -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 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型粘脂贮积症（MLII，MIM 252500）是一种溶酶体贮积症，由编码N-乙酰葡糖胺（GlcNAc）-1-磷酸转移酶α和β亚基的基因突变引起。新生儿表现包括面部粗糙、出生后生长受限、全身肌张力低下、牙龈肥大和多处骨骼异常。在此，我们报告一例孕26周的早产II型粘脂贮积症婴儿，其出生时未表现出典型面部特征；然而，胎盘病理异常显示滋养层脂质贮积症，胸部X线片显示全身弥漫性严重骨质脱矿质病和多处骨折，提示了该诊断。生化检测显示血浆溶酶体酶升高。测序发现纯合致病性变异，命名为c.3505_3504del。她的病程因呼吸窘迫、继发性甲状旁腺功能亢进、腹胀和喂养困难而复杂化。尿粘多糖分析显示总糖胺聚糖和各单糖胺聚糖种类轻度升高，呈非特异性模式。据我们所知，我们的病例是迄今为止报道的最早产的II型粘脂贮积症病例。本报告强调了胎盘病理研究在溶酶体贮积症诊断中的重要性。
