Supplementary Material Table 1. Primers used in the quantitative RT-PCR. Amplicon Primer Sequence FBXO31_1F GTGAGCTCCAGGAATGAGGA FBXO31_1R GATTTCAGCTCCAGCCAGAC FBXO31_2F GTTCTCCACCAAGTGCAACC FBXO31_2R ATTGAAGTTGCGCTGGTTCT FBXO31_3F GCCGTGAGGAGTATGGTGTT FBXO31_3R CGTTCAGCAGTCCTCCGTAT 1 2 3 Table 2. Primers used for validation of exon 7 mutation: Primer Sequence FBXO31_7F GGCCCTGGTTGAGCTGAG FBXO31_7R GGATCAGTGTCTGCCCAAGT Table 3. Whole exome sequencing statistics from individual IV:8. The single SNP remaining after filtering out dbSNP131 known SNPs, non-coding variants, heterozygous variants, and finally variants not within the two HBD regions on 16q, was in the gene KATNB1, c.599A>C; p.Asn200Thr, had low coverage (N=3 reads), and is predicted by PolyPhen2, ConDel, and others to be neutral . WES coverage Number of all variations Number of Homozygous variations Mean coverage Median coverage % variants with ≥3X coverage % variants with ≥10X coverage WES variants Number of SNPs Number of Indels Number of homozygous SNPs Number of homozygous Indels Number of homozygous coding SNPs Number of homozygous coding Indels Number of homozygous coding SNPs in HBD regions Number of homozygous coding Indels in HBD regions Number of coding exons with less than 3X coverage in HBD regions WES variants filtered for SNPs in dbSNP131 Number of homozygous coding SNPs Number of homozygous coding Indels Number of homozygous coding SNPs in HBD regions Number of homozygous coding Indels in HBD regions FBXO31 protein sequence: Wild-type FBXO31 protein MAVCARLCGVGPSRGCRRRQQRRGPAETAAADSEPDTDPEEERIEASAGV GGGLCAGPSPPPPRCSLLELPPELLVEIFASLPGTDLPSLAQVCTKFRRI LHTDTIWRRRCREEYGVCENLRKLEITGVSCRDVYAKLLHRYRHILGLWQ PDIGPYGGLLNVVVDGLFIIGWMYLPPHDPHVDDPMRFKPLFRIHLMERK AATVECMYGHKGPHHGHIQIVKKDEFSTKCNQTDHHRMSGGRQEEFRTWL REEWGRTLEDIFHEHMQELILMKFIYTSQYDNCLTYRRIYLPPSRPDDLI KPGLFKGTYGSHGLEIVMLSFHGRRARGTKITGDPNIPAGQQTVEIDLRH RIQLPDLENQRNFNELSRIVLEVRERVRQEQQEGGHEAGEGRGRQGPRES 43657 22136 13.10X 9X 91.8 46.5 41769 1888 21094 1042 20042 999 369 10 211 298 13 1 0 QPSPAQPRAEAPSKGPDGTPGEDGGEPGDAVAAAEQPAQCGQGQPFVLPV GVSSRNEDYPRTCRMCFYGTGLIAGHGFTSPERTPGVFILFDEDRFGFVW LELKSFSLYSRVQATFRNADAPSPQAFDEMLKNIQSLTS The epitope sequence where the C-terminal anti-FBXO31 antibodies (Bethyl Laboratories and Novus Biologicals) bind is indicated in blue (residues 489 to 539). Mutated Protein MAVCARLCGVGPSRGCRRRQQRRGPAETAAADSEPDTDPEEERIEASAGV GGGLCAGPSPPPPRCSLLELPPELLVEIFASLPGTDLPSLAQVCTKFRRI LHTDTIWRRRCREEYGVCENLRKLEITGVSCRDVYAKLLHRYRHILGLWQ PDIGPYGGLLNVVVDGLFIIGWMYLPPHDPHVDDPMRFKPLFRIHLMERK AATVECMYGHKGPHHGHIQIVKKDEFSTKCNQTDHHRMSGGRQEEFRTWL REEWGRTLEDIFHEHMQELILMKFIYTSQYDNNLPPHLPAAQPPRRPHQA WPLQRYLWQPRPGDCDAQLPRPACQGHQDHGRPQHPRWAADSGDRPEASD PAARPREPAQLQ* Amino acid sequence after the indel mutation and frameshift is indicated in red