A. Three pedigrees and four MOS variants were identified, including homozygous missense variant Asn95Lys in patient 1 (family 1), compound heterozygous missense variants Met139Thr and Arg246His in patient 2 (family 2) and homozygous nonsense variant Cys320Ter in patient 3 (family 3). The four MOS variants were inherited and identified via Sanger sequencing. WT indicates wild-type. 