Sialidosis, an autosomal recessive disorder, is characterized by progressive lysosomal storage of sialylated glycopeptides and oligosaccharides. It occurs as a result of biallelic mutations in the NEU1 gene. Sialidosis is traditionally classified as a milder, late-onset type I and a severe early-onset type II disease. The presence of a cherry-red spot is a well-established ophthalmological clue to the disorder. We present a clinical-radiological report of seven unrelated patients with molecularly confirmed sialidosis type II. To the best of our knowledge, This is the largest reported series of patients with Sialidosis type II. A novel, previously unreported ophthalmic phenotype of bulls-eye maculopathy, is described. All seven phenotypically heterogeneous patients had the same pathogenic variant (c.679G > A; p.Gly227Arg) at a homozygous level in the NEU1 gene. We propose that this is a common mutation in north Indians for this rare disorder. We also observed an overlap of symptoms and a continuum of phenotypes in type I and II Sialidosis.

唾液酸中毒是一种常染色体隐性遗传疾病，其特征在于唾液酸化的糖肽和寡糖的逐步溶酶体储存。它是NEU1中双等位基因突变的结果基因。传统上，唾液病被分类为轻度，迟发性I型疾病和重度早发性II型疾病。樱桃红色斑点的存在是该疾病的公认的眼科线索。我们提供了7例分子确认的II型唾液中毒无关患者的临床放射学报告。据我们所知，这是报告的最大的II型唾液中毒患者系列。描述了一种新颖的，以前未曾报道过的牛眼黄斑病变的眼表型。所有七个表型异质患者具有相同的致病变种（c.679G> A; p.Gly227Arg）在纯合水平NEU1基因。我们建议，这是北印度人这种罕见疾病的常见突变。我们还观察到I型和II型唾液酸中毒症状重叠和表型连续。