Our data indicate that HSCT for patients with GOF-STAT1 mutations is curative but has significant risk of secondary graft failure and death.

Background: Postzygotic de novo mutations lead to the phenomenon of gene mosaicism. The 3 main types are called somatic, gonadal, and gonosomal mosaicism, which differ in terms of the body distribution of postzygotic mutations. Mosaicism has been reported occasionally in patients with primary immunodeficiency diseases (PIDs) since the early 1990s, but its real involvement has not been systematically addressed. Objective: We sought to investigate the incidence of gene mosaicism in patients with PIDs. Methods: The amplicon-based deep sequencing method was used in the 3 parts of the study that establish (1) the allele frequency of germline variants (n 5 100), (2) the incidence of parental gonosomal mosaicism in families with PIDs with de novo mutations (n 5 92), and (3) the incidence of mosaicism in families with PIDs with moderate-to-high suspicion of gene mosaicism (n 5 36). Additional investigations evaluated body distribution of postzygotic mutations, their stability over time, and their characteristics. Results: The range of allele frequency (44.1% to 55.6%) was established for germline variants. Those with minor allele frequencies of less than 44.1% were assumed to be postzygotic. Mosaicism was detected in 30 (23.4%) of 128 families with PIDs, with a variable minor allele frequency (0.8% to 40.5%). Parental gonosomal mosaicism was detected in 6 (6.5%) of 92 families with de novo mutations, and a high incidence of mosaicism (63.9%) was detected among families with moderateto-high suspicion of gene mosaicism. In most analyzed cases mosaicism was found to be both uniformly distributed and stable over time. Conclusion: This study represents the largest performed to date to investigate mosaicism in patients with PIDs, revealing that it affects approximately 25% of enrolled families. Our results might have serious consequences regarding treatment and genetic counseling and reinforce the use of next-generation sequencing-based methods in the routine analyses of PIDs.

BackgroundThe aim of the research is to study the human leukocyte antigen (HLA) class II allele frequencies in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) associated with anti-neurofascin 155 (NF155) antibodies.MethodsThirteen anti-NF155+ and 35 anti-NF155 negative (anti-NF155neg) CIDP patients were included in a case-control study. The frequencies of the DRB1 HLA allele were analyzed in all patients while DQ frequencies were only studied in patients sharing the DRB1*15 allele. In silico HLA-peptide binding and NF155 antigenicity, predictions were performed to analyze overlap between presented peptides and antigenic regions.ResultsDRB1*15 alleles (DRB1*15:01 and DRB1*15:02) were present in 10 out of 13 anti-NF155+ CIDP patients and in only 5 out of 35 anti-NF155neg CIDP patients (77 vs 14%; OR = 20, CI = 4.035 to 99.13). DRB1*15 alleles appeared also in significantly higher proportions in anti-NF155+ CIDP than in normal population (77 vs 17%; OR = 16.9, CI = 4.434 to 57.30). Seven anti-NF155+ CIDP patients (53%) and 5 anti-NF155neg CIDP patients had the DRB1*15:01 allele (OR = 7, p = 0.009), while 3 anti-NF155+ CIDP patients and none of the anti-NF155neg CIDP patients had the DRB1*15:02 allele (OR = 23.6, p = 0.016). In silico analysis of the NF155 peptides binding to DRB1*15 alleles showed significant overlap in the peptides presented by the 15:01 and 15:02 alleles, suggesting functional homology.ConclusionsDRB1*15 alleles are the first strong risk factor associated to a CIDP subset, providing additional evidence that anti-NF155+ CIDP patients constitute a differentiated disease within the CIDP syndrome.Electronic supplementary materialThe online version of this article (10.1186/s12974-017-0996-1) contains supplementary material, which is available to authorized users.

Here we report a rapid and simple method to analyze an AccH polymorphism within the human p53 gene using the polymerase chain reaction. PCR Primers: The primer sequences corresponded to the 4th exon of the human p53 gene as described by Lamb (1). Sense oligo 5'-AATGGATGATTTGATGCTGTCCC-3' Antisense oligo 5'-CGTGCAAGTCACAGACTTGGC-3' Polymorphism: AccH (CGCG) digest of the amplified fragment identifies two alleles; Al = 259 bp and A2 = 160 bp + 99 bp. Frequency: Allele frequencies were calculated from 90 unrelated Caucasians. Al = 0.32 A2 = 0.68 Chromosomal Localization: The polymorphic AccH recognition site occurs within the 4th exon of the human p53 locus (17ql3) (2). Mendelian Inheritance: Co-dominant segregation demonstrated in 6 two-generation families. PCR Conditions: PCRs were carried out in a total volume of 50 ,ul containing: 500 ng of genomic DNA, 50 pmoles of each prii.ler, 2 mM MgCl2, 200 AM dNTPs, 50 mM KCl, 20 mM Tris-pH 8.3 and 0.1 % gelatine. The amplification is performed for 35 cycles with an annealing temperature of 62°C. The amplified DNA is digested overnight with a tenfold excess of AccH. DNA fragments are resolved by electrophoresis through a 2% agarose gel or a 7% polyacrylamide gel. Acknowledgements: This work was supported by a CAICYT Grant # PB 86-0046 del Ministerio de Educaci6n y Ciencia. 0. de la Calle-Martin was supported by a Hospital Clinic grant.