Affected individuals from 17 families (35.4%) had variants in known arthrogryposis-associated genes, including homozygous variants of cholinergic γ nicotinic receptor (CHRNG, 6 subjects) and endothelin converting enzyme-like 1 (ECEL1, 4 subjects).
Of 26 other reported recessive ECEL1 mutation cases (14 families), all had arthrogryposis, 19 had documented ptosis, and 4 had documented complex strabismus.