Patient iPSCs display unstable FLNA mRNA and no FLNa. (A) Quantitative reverse transcription polymerase chain reaction (qRT-PCR) primer design for the identification of the expressed X chromosome. Amplification of exon 2 allows detection of both WT and mutated messenger RNA (mRNA); that of exon 43 allows detection of only the WT mRNA. (B) qRT-PCR for FLNa expression on 2 different exons for several iPSC clones (9 FLNA^WT and 20 FLNA^mut clones for P1; 9 FLNA^WT and 10 FLNA^mut clones for P2). Results are presented as mean ± standard error of the mean; unpaired Student t test with Welch’s correction was used; each point represents 1 independent experiment. (C-D) Representative immunoblots for FLNa expression on 4 iPSC clones for each patient using a C-terminus–specific antibody (C) and a N-terminal antibody (D). Lines 1, 3, 5, and 7 represent FLNA^WT clones, and lines 2, 4, 6, and 8 represent FLNA^mut clones. (E) Immunoblot for FLNa expression on iPSCs cultivated for 60 passages using C-terminal antibody. Line 1 represents FLNA^WT clone, and lines 2 to 4 represent 3 different FLNA^mut clones. ***P < .001.