A Novel Intronic OCRL1 Variant Causing Lowe Syndrome with an Atypical Phenotype Mimicking Mucopolysaccharidosis

Abstract

Lowe syndrome is a rare X-linked recessive multisystem disorder caused by pathogenic OCRL1 variants. We describe a 19-month-old child with global developmental delay, bilateral congenital cataracts, glaucoma, and hypotonia but without clinically apparent renal involvement at last follow-up. Brain and spine magnetic resonance imaging revealed scaphocephaly, a J-shaped sella, peritrigonal white-matter abnormalities, and a soft-tissue lesion causing compression at the craniovertebral junction, suggestive of mucopolysaccharidosis. Whole-exome sequencing (WES) identified a novel pathogenic hemizygous splice-site variant, c. 1880-2A > G, in OCRL1 . This case highlights the atypical phenotype of Lowe syndrome, which mimics mucopolysaccharidosis, and the diagnostic utility of WES in such presentations.