The defective gene associated with LCCS1 is mRNA export mediator GLE1 at chromosome 9q34.
A slightly milder phenotype with survival beyond 32nd gestational week also characterized by foetal akinesia, arthrogryposis and anterior horn cell loss (Lethal arthrogryposis with anterior horn cell disease, LAAHD) was also shown to be allelic to LCCS1 and result from mutations in GLE1.