高磷酸血症伴智力低下综合征4(HPMRS4)是一种由糖基磷脂酰肌醇(GPI)缺乏引起的罕见常染色体隐性遗传疾病。GPI缺乏是由六个已知基因之一的突变引起的。GPI后与蛋白磷脂酶3基因(PGAP3)连接的突变与HPMRS4有关。患者通常表现为畸形特征,发育迟缓,中枢低张力,和癫痫。然而,在我们的案例中,我们报道了一个新的PGAP3基因纯合错义突变的女性儿童谁出现了巨大角膜,这是HPMRS4的不寻常临床表现。巨角膜,在她生命的第一天,导致原发性先天性青光眼的误诊。稍后,HPMRS4的其他常见临床特征变得明显。
Hyperphosphatasia with mental retardation syndrome 4 (HPMRS4) is a rare autosomal recessive disorder caused by glycosylphosphatidylinositol (GPI) deficiency. GPI deficiency results from a mutation in one of six known genes. Mutation in post-GPI attachment to protein phospholipase 3 gene (PGAP3) is linked to HPMRS4. Patients usually present with dysmorphic features, developmental delay, central hypotonia, and seizure. However, in our case, we report a novel homozygous missense mutation of PGAP3 gene in a female child who presented with megalocornea, which is an unusual clinical presentation for HPMRS4. Megalocornea, in her first days of life, led to a misdiagnosis of primary congenital glaucoma. Later, other common clinical features of HPMRS4 became apparent.