Pierson syndrome

Pierson syndrome (also known as microcoria-congenital nephrotic syndrome) is a rare autosomal recessive disorder caused by mutations in the LAMB2 gene, which encodes the laminin β2 chain, a critical component of basement membranes in the kidney, eye, and neuromuscular junction. The disease is characterized by congenital nephrotic syndrome with diffuse mesangial sclerosis and distinctive ocular abnormalities, most notably microcoria (fixed, narrow pupils due to abnormal development of the iris dilator muscle). The condition typically presents at birth or in the neonatal period with severe proteinuria and rapidly progressive renal failure. The ocular features of Pierson syndrome are a hallmark of the condition and may include microcoria, abnormalities of the lens (such as lenticonus or cataracts), retinal abnormalities, and glaucoma. Neurological involvement, including neurodevelopmental delay and muscular hypotonia, has also been reported in some patients, reflecting the role of laminin β2 in neuromuscular junctions and the central nervous system. The prognosis of classic Pierson syndrome is severe, with many affected infants progressing to end-stage renal disease within the first months to years of life. Treatment is primarily supportive and includes management of nephrotic syndrome (albumin infusions, nutritional support), dialysis, and ultimately kidney transplantation when feasible. The ocular abnormalities may require ophthalmological interventions. Milder phenotypic variants have been described in patients with certain LAMB2 mutations, where renal disease may progress more slowly and ocular findings may be less pronounced. There is currently no curative or disease-modifying therapy available. Genetic counseling is recommended for affected families.

Common questions about Pierson syndrome