Oculocerebrorenal syndrome

Oculocerebrorenal syndrome, or Lowe syndrome, is a rare X-linked disorder caused by pathogenic variants in OCRL. It characteristically affects the eyes, brain, and kidneys, including congenital cataracts and proximal renal tubule dysfunction.

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OCRL: A gene encoding an inositol polyphosphate 5-phosphatase involved in phosphoinositide signaling and membrane trafficking. Pathogenic variants in this gene cause Lowe syndrome by disrupting cellular phosphoinositide regulation.
Slit-lamp examination: An eye examination using a microscope and a narrow beam of light to inspect the anterior eye. It helps characterize cataracts and other eye abnormalities in suspected Lowe syndrome.
Dent disease: An X-linked proximal tubulopathy characterized by low-molecular-weight proteinuria, hypercalciuria, and kidney complications. It shares OCRL-related kidney disease but typically lacks Lowe syndrome’s congenital cataracts and neurological phenotype.
Charles Upton Lowe: A Canadian-American physician who described the syndrome now known as Lowe syndrome with colleagues in 1952. His clinical report established the recognizable combination of eye, neurological, and renal findings.
Genotype–phenotype correlation: The relationship between genetic variants and the observable features or severity of a condition. OCRL variants do not fully predict the severity of eye, neurological, or renal involvement.
Phosphoinositide signaling: Cellular signaling mediated by phosphorylated derivatives of phosphatidylinositol in cell membranes. OCRL normally modifies phosphoinositides, and its loss disrupts processes across affected tissues.
Renal tubular acidosis: A group of disorders in which impaired renal acid handling causes metabolic acidosis. Proximal tubular bicarbonate loss can cause acidosis requiring monitoring and treatment.
Congenital cataract facial dysmorphism neuropathy syndrome: A rare disorder involving congenital cataracts, distinctive facial features, and peripheral neuropathy, usually caused by MAF variants. Its cataracts overlap, but its genetic cause and characteristic neurological pattern differ.
Lowe syndrome: The common name for oculocerebrorenal syndrome, an X-linked disorder involving the eyes, brain, and kidneys. This eponym is used interchangeably with the formal name of the condition.
Mosaicism: The presence of genetically distinct cell populations within one individual arising from a single fertilized egg. Mosaic OCRL variants may help explain unusual clinical presentations and variation in severity.