Mutations in LAMB2are typically different in each family and more than 100 have been reported to date. Pathogenic variants in LAMB2include truncating (nonsense, frameshift, deletions, insertions, rearrangements, and splice site changes) and non-truncating changes (missense and in-frame variants).
Genetic testing is the ‘gold standard’ for the Congenital nephrotic syndrome or Pierson syndrome due to LAMB2variants. Knowing the variant not only make the diagnosis accurately but also helps predict the prognosis based on whether the variant is truncating or non-truncating.
In general, two truncating variants result in a worse prognosis than one truncating change, with earlier onset kidney failure, and an increased likelihood of ocular and neuromuscular abnormalities. Although mutations in the amino terminus of the protein or LN domain (residues Ser43 to Asn282) of the laminin β2 chain are reported to be more common, a recent study has suggested that these are not necessarily associated with a worse prognosis.
LAMB2