Congenital nephrotic syndrome or Pierson syndrome due to biallelic LAMB2 mutations is rare. It is characterised by nephrotic syndrome soon after birth or in infancy and kidney failure. The baby is usually born with ocular abnormalities (a small eye, squnits, cataracts, pigmented retina, optic nerve hypoplasia and impaired vision) as well as neuromuscular features (delayed motor development and myopathy. Cognition is normal. The kidney biopsy demonstrates diffuse mesangial sclerosis. Electron microscopy of the neuromuscular junction may demonstrate small axon terminal , widening of the synaptic clefts and decreased number of synaptic vesicles.
LAMB2