Our finding confirms the genetic/clinical heterogeneity of the disorder; corroborated by previous identification of ADCY5 mutations in one family with dyskinesia-facial myokymia and in two unrelated sporadic cases of paxoysmal choreic/dystonia-facial myokymia; ADCY5's high expression in the striatum and movement disorders in ADCY5-deficient mice. Hence ADCY5 genetic analyses may be relevant in the diagnostic workup of unexplained early-onset hyperkinetic movement disorders.

Key Points• Matching for MICA significantly reduces the incidence of acute and chronic GVHD in otherwise HLA 10/ 10-matched unrelated-donor HCT.• Our results formally define MICA as a novel major histocompatibility complex-encoded human transplantation antigen.

The association of primary Sjögren's syndrome (pSS) with Major Histocompatibility Complex (MHC) alleles is quintessential of MHC-disease associations. Indeed, although disease associations with classical HLA class I and II alleles/haplotypes are amply documented, further dissection is often prevented by the strong linkage disequilibrium across the entire MHC complex. Here we study the association of pSS, not with HLA genes, but with the non-conventional MHC encoded class I gene, MICA (MHC class I chain-related gene A). MICA is selectively expressed within epithelia, and is the major ligand for the activatory receptor, NKG2D, both attributes relevant to pSS' etiology. MICA-pSS association was studied in two independent (French and UK) cohorts representing a total of 959 cases and 1,043 controls. MICA*008 allele was shown to be significantly associated with pSS (pcor=2.61 × 10-35). A multivariate logistic regression showed that this association was independent of all major known MHC-linked risk loci/alleles, as well as other relevant candidate loci that are in linkage disequilibrium with MICA*008 i.e. HLA-B*08:01, rs3131619 (T), MICB*008, TNF308A, HLA-DRB1*03:01 and HLA-DRB1*15:01 (P = 1.84 × 10-04). Furthermore, independently of the MICA*008 allele, higher levels of soluble MICA proteins were detected in sera of pSS patients compared to healthy controls. This study hence defines MICA as a new, MHC-linked, yet HLA-independent, pSS risk locus and opens a new front in our understanding of the still enigmatic pathophysiology of this disease. The fact that the soluble MICA protein is further amplified in MICA*008 carrying individuals, might also be relevant in other auto-immune diseases and cancer.

The identity of histocompatibility loci, besides human leukocyte antigen (HLA), remains elusive. The major histocompatibility complex (MHC) class I MICA gene is a candidate histocompatibility locus. Here, we investigate its role in a French multicenter cohort of 1,356 kidney transplants. MICA mismatches were associated with decreased graft survival (hazard ratio (HR), 2.12; 95% confidence interval (CI): 1.45–3.11; P < 0.001). Both before and after transplantation anti-MICA donor-specific antibodies (DSA) were strongly associated with increased antibody-mediated rejection (ABMR) (HR, 3.79; 95% CI: 1.94–7.39; P < 0.001; HR, 9.92; 95% CI: 7.43–13.20; P < 0.001, respectively). This effect was synergetic with that of anti-HLA DSA before and after transplantation (HR, 25.68; 95% CI: 3.31–199.41; P = 0.002; HR, 82.67; 95% CI: 33.67–202.97; P < 0.001, respectively). De novo-developed anti-MICA DSA were the most harmful because they were also associated with reduced graft survival (HR, 1.29; 95% CI: 1.05–1.58; P = 0.014). Finally, the damaging effect of anti-MICA DSA on graft survival was confirmed in an independent cohort of 168 patients with ABMR (HR, 1.71; 95% CI: 1.02–2.86; P = 0.041). In conclusion, assessment of MICA matching and immunization for the identification of patients at high risk for transplant rejection and loss is warranted.

Infection with human BK polyomavirus, a small double-stranded DNA virus, potentially results in severe complications in immunocompromised patients. Here, we describe the in vivo variability and evolution of the BK polyomavirus by deep sequencing. Our data reveal the highest genomic evolutionary rate described in double-stranded DNA viruses, i.e., 10−3–10−5 substitutions per nucleotide site per year. High mutation rates in viruses allow their escape from immune surveillance and adaptation to new hosts. By combining mutational landscapes across viral genomes with in silico prediction of viral peptides, we demonstrate the presence of significantly more coding substitutions within predicted cognate HLA-C-bound viral peptides than outside. This finding suggests a role for HLA-C in antiviral immunity, perhaps through the action of killer cell immunoglobulin-like receptors. The present study provides a comprehensive view of viral evolution and immune escape in a DNA virus.

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Noonan syndrome (NS), an autosomal dominant multisystem disorder, is caused by the dysregulation of the RAS-MAPK pathway and is characterized by short stature, heart defects, pectus excavatum, webbed neck, learning problems, cryptorchidism and facial dysmorphism. We here present the clinical and molecular characterization of a family with NS and multiple giant cell lesions (MGCLs). The proband is a 12-year-old girl with NS and MGCL. Her mother shows typical NS without MGCL. Whole-exome sequencing of the girl, her mother and her healthy maternal grand parents revealed a previously unobserved mutation in exon 5 of the PTPN11 gene (c.598 A>T; p.N200Y), transmitted from the mother to the proband. As no other modification in the RAS-MAPK pathway genes as related to Rasopathies was detected in the proband, this report demonstrates for the first time that a unique mutation affecting this, otherwise unaffected signaling route, can cause both NS and NS/MGCL in the same family. This observation further confirms that NS/MGCL is not a distinct entity but rather that MGCL represents a rare complication of NS. Moreover, the localization of the p.N200Y mutation suggests an alternative molecular mechanism for the excessive phosphatase activity of the PTPN11-encoded protein.