SMCHD1 and facioscapulohumeral muscular dystrophy: Furthermore, as highlighted by molecular combing [81], a significant proportion of individuals affected by FSHD display an atypical genotype, with complex distal rearrangements [82], presence of proximal deletions, additional 10q alleles, in the absence of D4Z4 array shortening, SMCHD1 variants, or D4Z4 hypomethylation [83].