Figure 1

(a) Family pedigree. Genotyped individuals are indicated as WT +/Y or +/+; carrier −/+; affected -/Y. XCI ratios (peripheral blood DNA) for the tested females are shown (Supplementary Table 3). Foetus II-6 was a missed miscarriage at 25/40, III-3 died in the neonatal period at 36/40, III-5 was stillborn at 34/40, and pregnancies III-7 and IV-1 were terminated at 21/40 and 18.5/40, respectively, following diagnosis by ultrasound. IUGR, intrauterine growth restriction. (b) Schematic structure of GPKOW gene and protein. Arrow indicates location of +5G>A variant in the donor splice site of exon 2. One G-Patch domain, two KOW motifs and a predicted nuclear localisation sequence (NLS, aa 331–334) are shown. Exons are numbered as in NCBI Refseq NG_021310.2 and the amino acid locations of different domains are from the NCBI Refseq NP_056513.2. The shaded box indicates the aa 59–189 missing from the truncated protein, based on transcript D cDNA sequence. (c) Schematic representation of the four different transcripts identified in the cycloheximide (CHX) assay. Asterisks represent premature termination codons (PTC) introduced due to shifts in reading frame. (d) c.331+5G>A carrier female LCLs show additional aberrant processing of GPKOW pre-mRNA. Agarose gel showing GPKOW transcripts amplified from carrier and control female LCLs cultured in the presence (+) or absence (–) of CHX. Full-length (WT) and aberrantly-spliced (A–D) transcripts are indicated by arrows. XCI ratios assayed from LCL gDNA from three carrier females are also shown.