Variants in LINC complex-encoding genes may explain the heterogeneity in disease severity, as EDMD patients with mutations in SUN1 or SUN2, along with mutations in other genes like EMD or LMNA, had more severe symptoms compared to relatives without SUN gene mutations, although the SUN mutations alone were not linked to disease in other family members. Here, SUN1 is linked to Emery-Dreifuss muscular dystrophy.