A Novel <scp> <i>PLCD1</i> </scp> Variant in Familial Trichilemmal Cysts With Leukonychia: Per‐Cyst Second Hits Support a Monoallelic Two‐Hit Mechanism

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions. Data S1: Supplementary methods. Figure S1: Full-length PLCD1 RT-PCR from cyst-derived cDNA. First-strand cDNA (oligo-dT primed) from the proband's cysts 1–4 and a healthy scalp control (C) was used to amplify a 2523-bp PLCD1 cDNA encompassing all coding exons. Each cyst yielded a single expected-size band comparable to the control; GAPDH served as an internal control. MWM, molecular weight markers. Figure S2: (a) Sanger sequencing of full-length PLCD1 cDNA from cyst-derived RNA identified lesion-specific somatic second hits (c.614A>G [p.Tyr205Cys]). (b) Cloning of PLCD1 RT-PCR products followed by sequencing of individual clones demonstrated that the second hits are in cis with the germline c.2122G>T allele (l: c.614A>G). (c) Sequencing of cyst-derived genomic DNA from the corresponding lesions confirmed the same second hit (m: c.614A>G). Figure S3: (a) Sanger sequencing of full-length PLCD1 cDNA from cyst-derived RNA identified lesion-specific somatic second hits (c.2129C>T [p.Ser710Phe]). (b) Cloning of PLCD1 RT-PCR products followed by sequencing of individual clones demonstrated that the second hits are in cis with the germline c.2122G>T allele (c.2129C>T). (c) Sequencing of cyst-derived genomic DNA from the corresponding lesions confirmed the same second hit (c.2129C>T). Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.