In subject 3, who had a severe AMC form and deceased at the age of 3 months, trio ES detected the compound heterozygous COL25A1 variants c.367G > C and c.1198G > T, predicting the amino acid substitution p.(Gly123Arg) and p.(Gly400Trp), respectively (Supplementary Fig. S1A). Here, COL25A1 is linked to arthrogryposis multiplex congenita.