S1 (Supplementary Figure 1). Pedigrees and haplotypes of the studied families.
Family 1(A), patient 1 is denoted IV:8. Her sister (IV:6) had molecularly confirmed
Prader-Willi syndrome. The parents are expecting another child. The patient’s
maternal uncle married the patient’s paternal aunt and one of their children (IV:11)
has an undiagnosed congenital condition. Family 2 (B). Patients 2 and 3 are denoted
IV:1 and IV:2. Haplotypes of the patients and their parents are also shown. All
patients were homozygous for a small region containing the ALG9 gene, suggesting
the presence of a common founder variant in these two unrelated families.
S2. Supplementary Table 1. Primers used for Sanger sequencing for variant
confirmation (denoted g) and cDNA analysis (denoted c) of the ALG9 gene. The two
different sizes marked by asterisk correspond to different splice isoforms in exon 11.
bp=base pairs.
S3 (Supplementary Figure 2). Pathogenic variants in the ALG9 gene in the patients
and their parents. (A) Family 1 patient 1 (IV:8) and her parents (III:6 & III:7), (B)
Family 2, patients 2 (IV:1) and 3 (IV:2) and their parents (III:13 & III:14).
Homozygous variants are marked by arrow, whereas heterozygous by W.
S4 (Supplementary Figure 3). Representative gel picture showing results from
cDNA amplification of the samples from the patients, their parents and normal
controls using primers on exon 9 and 11. (1) 123 bp marker; (2) patient 1; (3) mother
of patient 1; (4) father of patient 1; (5) patient 2; (6) patient 3; (7) mother of patients
2&3; (8) father of patients 2&3; (9) control fetus 1; 10. lymphocytes of normal adult;
11. negative control (no RNA added); 12. 123 bp marker. For patients only a short
fragment of 106 bp is seen, because of exon 10 skipping, whereas for heterozygous
parents both 106 bp and 261 bp fragments are seen. For healthy control fetus and
adult lymphocytes the 261 bp fragment is predominant. A weak 106 bp band was
noticed in both fetal and adult normal control samples indicating that a low scale of
the defect RNA splicing is present in normal individuals, which does not have
consequences for ALG9 protein function.
S5 (Supplementary Figure 4). Evolutionary comparison of the ALG9 protein
sequence corresponding to exon 10 in human NP_079016.2. Note that the protein
sequence coded by exon 10 (marked by grey background) of ALG9 gene is highly
evolutionary conserved.
S6 (Supplementary Figure 5). Mass spectra analysis of transferrin from spleen and
serum of normal control individuals. Mass spectra of affinity purified transferrin
before (A, C) and after deconvolution (B, D). Panel A/B; representative mass data of
transferrin from spleen of an adult control individual. Panel C/D; representative mass
data of transferrin from serum of an adult control individual. Note that spleen-derived
Trf analysis matches the profile of serum-derived transferrin.
S7. Supplementary table 2. Comparison of radiologic and other common features in
our patients with ALG9-CDG with those previously reported in patients with ALG3and ALG12-CDG.