Congenital distal spinal muscular atrophy is caused by a mutation of the TRPV4 gene found on the 12q23-12q24.1. The mutation causes an affected individual to have lower levels of TRPV4 expression. This deficiency can lead to abnormal osmotic regulation. Congenital dSMA is genetically heterogeneous, meaning a mutation on this gene can cause a plethora of other phenotypically related or phenotypically unrelated diseases depending on the region that is mutated.