UBA2 variants underlie a recognizable syndrome with variable aplasia cutis congenita and ectrodactyly.

PURPOSE: The human chromosome 19q13.11 deletion syndrome is associated with a variable phenotype that includes aplasia cutis congenita (ACC) and ectrodactyly as specific features. UBA2 (ubiquitin-like modifier-activating enzyme 2) lies adjacent to the minimal deletion overlap region. We aimed to define the UBA2-related phenotypic spectrum in humans and zebrafish due to sequence variants and to establish the mechanism of disease. METHODS: Exome sequencing was used to detect UBA2 sequence variants in 16 subjects in 7 unrelated families. uba2 loss of function was modeled in zebrafish. Effects of human missense variants were assessed in zebrafish rescue experiments. RESULTS: Seven human UBA2 loss-of-function and missense sequence variants were detected. UBA2-phenotypes included ACC, ectrodactyly, neurodevelopmental abnormalities, ectodermal, skeletal, craniofacial, cardiac, renal, and genital anomalies. uba2 was expressed in zebrafish eye, brain, and pectoral fins; uba2-null fish showed deficient growth, microcephaly, microphthalmia, mandibular hypoplasia, and abnormal fins. uba2-mRNAs with human missense variants failed to rescue nullizygous zebrafish phenotypes. CONCLUSION: UBA2 variants cause a recognizable syndrome with a wide phenotypic spectrum. Our data suggest that loss of UBA2 function underlies the human UBA2 monogenic disorder and highlights the importance of SUMOylation in the development of affected tissues.

Autoimmune Variant PTPN22 C1858T Is Associated With Impaired Responses to Influenza Vaccination.

High-affinity-antibody production, T-cell activation, and interferon upregulation all contribute to protective immunity that occurs in humans following influenza immunization. Hematopoietic cell-specific PTPN22 encodes lymphoid phosphatase (Lyp), which regulates lymphocyte antigen receptor and pattern recognition receptor (PRR) signaling. A PTPN22 variant, R620W (LypW), predisposes to autoimmune and infectious diseases and confers altered signaling through antigen receptors and PRRs. We tested the hypothesis that LypW-bearing humans would have diminished immune response to trivalent influenza vaccine (TIV). LypW carriers exhibited decreased induction of influenza virus-specific CD4(+) T cells expressing effector cytokines and failed to increase antibody affinity following TIV receipt. No differences between LypW carriers and noncarriers were observed in virus-specific CD8(+) T-cell responses, early interferon transcriptional responses, or myeloid antigen-presenting cell costimulatory molecule upregulation. The association of LypW with defects in TIV-induced CD4(+) T-cell expansion and antibody affinity maturation suggests that LypW may predispose individuals to have a diminished capacity to generate protective immunity against influenza virus.