Dominant dystrophic epidermolysis bullosa is associated with glycolytically active GATA3+ Th2 cells which may contribute to pruritus in lesional skin.

BACKGROUND: Dominant dystrophic epidermolysis bullosa (DDEB) is characterized by trauma-induced blisters and, in some individuals, intense pruritus. Precisely what causes itch in DDEB and optimal ways to reduce it have not been fully determined. OBJECTIVE: To characterize DDEB skin transcriptomes to identify therapeutic targets to reduce pruritus in patients. METHODS: We evaluated affected and unaffected skin biopsy samples from 6 DDEB subjects (all with the very itchy pruriginosa subtype), and 4 healthy individuals using bulk RNA-seq. Single-cell transcriptomes of affected (n=2) and unaffected (n=1) DDEB and healthy skin (n=2) were obtained. Dupilumab treatment was provided for three patients. RESULTS: The skin bulk transcriptome showed significant enrichment of Th1/2 and Th17 pathways in affected DDEB skin compared with non-lesional DDEB and healthy skin. Single-cell transcriptomics showed an association of glycolytically active GATA3+ Th2 cells in affected DDEB skin. Treatment with dupilumab in three people with DDEB led to significantly reduced VAS itch scores after 12 weeks (mean VAS=3.83) compared to pre-treatment (mean VAS=7.83). Bulk RNA-seq and qPCR showed that healthy skin and dupilumab-treated epidermolysis bullosa (EB) pruriginosa skin show very similar transcriptomic profiles, and reduced Th1/2 and Th17 pathway enrichment. CONCLUSIONS: Single-cell RNA-seq helps define an enhanced DDEB-associated Th2 profile and rationalizes drug repurposing of anti-Th2 drugs in treating DDEB pruritus.

Genetic Diagnosis of Rubinstein-Taybi Syndrome With Multiplex Ligation-Dependent Probe Amplification (MLPA) and Whole-Exome Sequencing (WES): Case Series With a Novel CREBBP Variant.

Rubinstein-Taybi Syndrome (RSTS) is a rare congenital disease with distinctive facial features, broadening of the thumbs and halluces, and developmental delay. RSTS is caused by de novo genetic alterations in CREBBP and the homologous EP300 genes. In this study, we established a genetic diagnostic protocol by integrating multiplex ligation-dependent probe amplification (MLPA) and whole-exome sequencing (WES). Five patients clinically diagnosed with RSTS were enrolled for genetic testing. Germline DNA was extracted from the peripheral blood of the patients and their families. One patient (case 1) was identified as harboring a large heterozygous deletion in the 16p13.3 region, spanning the CREBBP gene. Three patients (Cases 2-4) harbored different CREBBP variants (c.2608C>T:p.Gln870Ter,c.4404_4405del:p.Thr1468fs,c.3649C>T:p.Gln1217Ter). No causative variants were identified for the fifth RSTS patient (case 5). Here, we propose a molecular diagnostic protocol that identified causative genetic alterations in 4/5 of the patients, yielding a molecular diagnostic rate of 80%. Given the rarity of RSTS, more research is needed to explore its pathogenesis and mechanism.