Thymectomy in Juvenile Myasthenia Gravis Is Safe Regarding Long Term Immunological Effects.

Thymectomy is an established treatment in adult MG and also recommended for the treatment of post-pubertal onset juvenile MG. Whether the youngest children should be thymectomized is still debated. Signs of premature aging of the immune system have been shown in studies on early perioperative thymectomy in children with congenital heart defect. In this retrospective cohort study the objective was to investigate the long-term effects of treatment related thymectomy on T cell subsets and T cell receptor rearrangement excision circles (TRECs) in peripheral blood of juvenile myasthenia gravis (MG) patients, as well as clinical occurrence of autoimmune disorders, malignancies and infectious diseases. Forty-seven patients with onset of myasthenia gravis before the age of 19 years were included; 32 (68.1%) had been thymectomized and 15 (31.8%) had not. They were studied at varying times after thymectomy (7-26 years). We found a significant lower number of naïve helper T cells (CD4+CD45RA+) with an increased proportion of memory helper T cells (CD4+CD45RO+), and a significant lower number of naïve cytotoxic T cells (CD8+CD27+CD28+) in the thymectomized patients. In addition they showed a significant reduction in the number of TRECs and proportion of recent thymic emigrants (RTE) compared to non-thymectomized patients. In none of them an increased frequency of malignancies or infections was found. Our findings indicate a premature aging of the immune system after thymectomy in juvenile MG, but associated clinical consequences could not be verified.

Second-Tier Next Generation Sequencing Integrated in Nationwide Newborn Screening Provides Rapid Molecular Diagnostics of Severe Combined Immunodeficiency.

Severe combined immunodeficiency (SCID) and other T cell lymphopenias can be detected during newborn screening (NBS) by measuring T cell receptor excision circles (TRECs) in dried blood spot (DBS) DNA. Second tier next generation sequencing (NGS) with an amplicon based targeted gene panel using the same DBS DNA was introduced as part of our prospective pilot research project in 2015. With written parental consent, 21 000 newborns were TREC-tested in the pilot. Three newborns were identified with SCID, and disease-causing variants in IL2RG, RAG2, and RMRP were confirmed by NGS on the initial DBS DNA. The molecular findings directed follow-up and therapy: the IL2RG-SCID underwent early hematopoietic stem cell transplantation (HSCT) without any complications; the leaky RAG2-SCID received prophylactic antibiotics, antifungals, and immunoglobulin infusions, and underwent HSCT at 1 year of age. The child with RMRP-SCID had complete Hirschsprung disease and died at 1 month of age. Since January 2018, all newborns in Norway have been offered NBS for SCID using 1st tier TRECs and 2nd tier gene panel NGS on DBS DNA. During the first 20 months of nationwide SCID screening an additional 88 000 newborns were TREC tested, and four new SCID cases were identified. Disease-causing variants in DCLRE1C, JAK3, NBN, and IL2RG were molecularly confirmed on day 8, 15, 8 and 6, respectively after birth, using the initial NBS blood spot. Targeted gene panel NGS integrated into the NBS algorithm rapidly delineated the specific molecular diagnoses and provided information useful for management, targeted therapy and follow-up i.e., X rays and CT scans were avoided in the radiosensitive SCID. Second tier targeted NGS on the same DBS DNA as the TREC test provided instant confirmation or exclusion of SCID, and made it possible to use a less stringent TREC cut-off value. This allowed for the detection of leaky SCIDs, and simultaneously reduced the number of control samples, recalls and false positives. Mothers were instructed to stop breastfeeding until maternal cytomegalovirus (CMV) status was determined. Our limited data suggest that shorter time-interval from birth to intervention, may prevent breast milk transmitted CMV infection in classical SCID.

T-cell Receptor Excision Circles in Newborns with Heart Defects.

In the fetus, the cardiac neural crest gives rise to both the thymus and the conotruncus of the heart. In newborn screening for severe T-cell lymphopenia neonates with congenital heart defects may be detected. In this study, we investigated the occurrence of T-cell lymphopenia in neonates with or without 22q11.2 deletion syndrome (del) suffering from heart defects. This retrospective cohort study included 125 patients with heart defects. T-cell receptor excision circles (TRECs), a measure for T-cell lymphopenia, were quantified by RT-PCR using stored newborn screening blood spots. Three patient groups were compared: non-conotruncal defects (n = 57), conotruncal defects (n = 42), and 22q11.2 del with conotruncal defects (n = 26). Significantly lower TREC values were detected in patients with 22q11.2 del and conotruncal heart defects compared to those with non-syndromic conotruncal (p < 0.001) and non-conotruncal (p < 0.001) defects. In contrast, no significant difference was found between patients with non-syndromic conotruncal and non-conotruncal heart defects (p = 0.152). Low TREC levels were obtained in neonates treated with heart surgery/intervention within 2 weeks after birth and in those with a fatal outcome (p = 0.02) independent of patient group. A correlation was found between low TREC numbers and oxygen saturation, SpO2 below 95% (p = 0.017). The SpO2 was significantly lower in the non-syndromic conotruncal group compared to non-conotruncal (p < 0.001) and 22q11.2 del group (p = 0.015). No correlation was found between low neonatal TRECs and infections needing hospitalization later in life (p = 0.135). Patients with 22q11.2 del and conotruncal defects have significantly lower TREC levels compared to patients with heart defects without this syndrome.

Complement Activation in 22q11.2 Deletion Syndrome.

The 22q11.2 deletion syndrome (22q11.2 del), also known as DiGeorge syndrome, is a genetic disorder with an estimated incidence of 1:3000 to 1:6000 births. These patients may suffer from affection of many organ systems with cardiac malformations, immunodeficiency, hypoparathyroidism, autoimmunity, palate anomalies, and psychiatric disorders being the most frequent. The importance of the complement system in 22q11.2 del has not been investigated. The objective of this study was to evaluate the complement system in relation to clinical and immunological parameters in patients. A national cohort of patients (n = 69) with a proven heterozygous deletion of chromosome 22q11.2 and a group of age and sex matched controls (n = 56) were studied. Functional capacity of the classical, lectin, and alternative pathways of the complement system as well as complement activation products C3bc and terminal complement complex (TCC) were accessed and correlated to clinical features. All patients in our study had normal complement activation in both classical and alternative pathways. The frequency of mannose-binding lectin deficiency was comparable to the normal population. The patients had significantly raised plasma levels of C3bc and a slight, but not significant, increase in TCC compared with controls. This increase was associated with the presence of psychiatric disorders in patients. The present study shows no complement deficiencies in 22q11.2 deletion syndrome. On the contrary, there are signs of increased complement activation in these patients. Complement activation is particularly associated with the presence of psychiatric disorders.

Lymphocyte Apoptosis and FAS Expression in Patients with 22q11.2 Deletion Syndrome.

PURPOSE: Immunodeficiency is one of the key features of 22q11.2 deletion syndrome (del), and it is seen in approximately 75% of the patients. The degree of immunodeficiency varies widely, from no circulating T cells to normal T cell counts. It has been hypothesized that the low number of T cells may at least in part be due to increased apoptosis of T cells. Increased spontaneous T cell apoptosis has been reported in one patient with 22q11.2del, but this has not been further investigated. METHODS: A national cohort of patients with a proven heterozygous deletion of chromosome 22q11.2 diagnosed by FISH or MLPA and a group of age and sex matched controls were studied. Spontaneous and activation-induced apoptosis, in addition to FAS expression on lymphocytes, were measured using flow cytometry. Serum levels of FASL were analyzed using ELISA. RESULTS: There was no increased spontaneous apoptosis in patients with 22q11.2del. Upon activation, anti-FAS-induced apoptosis was significantly increased in patients compared to those in controls, while there was no difference in activation induced cell death or activated cell autonomous death. We also found a significant increase in expression of FAS on freshly isolated lymphocytes from patients, while there was no difference in serum levels of FASL. Patients with congenital heart defects (CHD) had significantly higher serum levels of FASL compared to non-CHD patients. CONCLUSION: We have shown increased FAS expression on lymphocytes from patients with 22q11.2del as well as increased levels of FASL in patients with CHD. Those changes may contribute to the pathophysiology of the 22q11.2del.

Correction: Impact of extensive antibiotic treatment on faecal carriage of antibiotic-resistant enterobacteria in children in a low resistance prevalence setting.

[This corrects the article DOI: 10.1371/journal.pone.0187618.].

Transfer of a bla CTX-M-1-carrying plasmid between different Escherichia coli strains within the human gut explored by whole genome sequencing analyses.

Horizontal transfer of antibiotic resistance determinants contributes to dissemination of antibiotic resistance. Such transfer of resistance genes within the human gut has been documented in some in vivo studies. The present study investigated seven bla CTX-M-1-carrying Escherichia coli isolates from three consecutive faecal samples collected from one cystic fibrosis patient in a nine-months period, by analysing whole genome sequencing data. The analyses showed that the seven E. coli isolates represented three genetically diverse strains. All isolates contained bla CTX-M-1-carrying Incl1 plasmids that shared a common 101 kb backbone differing by only four SNPs. The plasmids harboured by the three different E. coli strains varied within limited regions suggestive of recombination events, according to the phylogenetic topology of the genomes of the isolates harbouring them. The findings strongly suggest that horizontal transfer of a bla CTX-M-1-carrying plasmid had occurred within the patient´s gut. The study illustrates the within-host diversity of faecally carried resistant E. coli isolates and highlights the value of collecting multiple bacterial colonies from longitudinally collected samples to assess faecal carriage of resistant enterobacteria. The clustering of the plasmids with the corresponding E. coli strains carrying them indicates that the plasmids appear to have adapted to their respective E. coli hosts.

Strictly controlled glucose infusion rates are associated with a reduced risk of hyperglycaemia in extremely low birth weight preterm infants.

AIM: We evaluated a strict strategy that aimed to avoid fluctuations in glucose infusion rates (GIRs) and assessed the independent effects of maximal daily GIRs on the hyperglycaemia risk among extremely low birth weight (ELBW) infants receiving early enhanced parenteral nutrition. METHODS: This study comprised all ELBW infants admitted to the neonatal intensive care unit of Oslo University Hospital Rikshospitalet, Norway, before (2007-2009) and after (2012-2013) implementing a strict GIR strategy. Severe hyperglycaemia was defined as two consecutive blood glucose values over 12 mmol/L. Maximum daily GIRs (mg/kg/min) were categorised into low (<5.1), intermediate (5.1-7.0) or high (>7.0). Mixed effects logistic regression modelling for repeated measurements was applied to investigate independent determinants of hyperglycaemia. RESULTS: We included 1293 treatment days for 195 infants. The maximum daily GIR decreased (6.3 versus 5.8 mg/kg/min), while mean daily glucose and energy intakes were maintained in the post-strategy period. The prevalence of severe hyperglycaemia (48% versus 23%), insulin use (39% versus 16%) and mortality (26% versus 10%) fell. Intermediate GIR (odds ratio 2.11) and high GIR (odds ratio 2.85) were significant independent predictors of severe hyperglycaemia compared to low GIR. CONCLUSION: A strict GIR strategy reduced the risk of severe hyperglycaemia and adverse outcomes.

Adults with 22q11.2 deletion syndrome have a different velopharyngeal anatomy with predisposition to velopharyngeal insufficiency.

AIM: To find out if subjects with 22q11.2 deletion syndrome (DS) have a different velopharyngeal anatomy which could cause velopharyngeal insufficiency (VPI). METHODS: A prospective study of 16 subjects >16 years of age with 22q11.2 DS, without overt cleft palate and without previous VPI surgery, and 48 healthy controls >18 years of age were included in the study. Speech was recorded and scored blindly by two independent senior speech therapists. All 64 individuals had MRI scans, which were analyzed blindly by a consultant radiologist. RESULTS: Subjects with 22q11.2 DS had a mild degree of weak pressure consonants (mean score); borderline to mild degree of hypernasality and audible nasal emission (mean score). All controls had normal speech. When comparing subjects (22q11.2 DS) to controls, we found the subjects to have the following: A shorter distance between left and right points of origin of the levator veli palatini muscle (LVP) (p < 0.0001); a more obtuse angle of origin of the LVP (bilaterally) (p < 0.009); a thinner LVP bilaterally and in the midline (p < 0.0001); a shorter LVP bilaterally (p < 0.0001); a shorter velum (p = 0.007); a larger osseous pharyngeal depth:velar length ratio (p = 0.01); a more obtuse anterior cranial base angle (nasion to sella to basion) (p < 0.0001) and posterior cranial base angle (sella to basion to foramen magnum) (p < 0.0001); a wider velopharyngeal width (p = 0.002) and a larger pharyngeal airway volume (p = 0.0007). CONCLUSION: Compared with healthy controls, adults with 22q11.2 DS showed a different velopharyngeal anatomy, which will make these individuals more prone to VPI.

Impact of extensive antibiotic treatment on faecal carriage of antibiotic-resistant enterobacteria in children in a low resistance prevalence setting.

We prospectively studied the consequences of extensive antibiotic treatment on faecal carriage of antibiotic-resistant enterobacteria in a cohort of children with cystic fibrosis (CF) and a cohort of children with cancer compared to healthy children with no or low antibiotic exposure. The study was conducted in Norway in a low resistance prevalence setting. Sixty longitudinally collected faecal samples from children with CF (n = 32), 88 samples from children with cancer (n = 45) and 127 samples from healthy children (n = 70) were examined. A direct MIC-gradient strip method was used to detect resistant Enterobacteriaceae by applying Etest strips directly onto agar-plates swabbed with faecal samples. Whole genome sequencing (WGS) data were analysed to identify resistance mechanisms in 28 multidrug-resistant Escherichia coli isolates. The prevalence of resistance to third-generation cephalosporins, gentamicin and ciprofloxacin was low in all the study groups. At inclusion the prevalence of ampicillin-resistant E. coli and trimethoprim-sulfamethoxazole-resistant E. coli in the CF group compared to healthy controls was 58.6% vs. 28.4% (p = 0.005) and 48.3% vs. 14.9% (p = 0.001), respectively, with a similar prevalence at the end of the study. The prevalence of resistant enterobacteria was not significantly different in the children with cancer compared to the healthy children, not even at the end of the study when the children with cancer had been treated with repeated courses of broad-spectrum antibiotics. Children with cancer were mainly treated with intravenous antibiotics, while the CF group mainly received peroral treatment. Our observations indicate that the mode of administration of antibiotics and the general level of antimicrobial resistance in the community may have an impact on emergence of resistance in intestinal enterobacteria during antibiotic treatment. The WGS analyses detected acquired resistance genes and/or chromosomal mutations that explained the observed phenotypic resistance in all 28 multidrug-resistant E. coli isolates examined.

Primary immunodeficiency diseases: Genomic approaches delineate heterogeneous Mendelian disorders.

BACKGROUND: Primary immunodeficiency diseases (PIDDs) are clinically and genetically heterogeneous disorders thus far associated with mutations in more than 300 genes. The clinical phenotypes derived from distinct genotypes can overlap. Genetic etiology can be a prognostic indicator of disease severity and can influence treatment decisions. OBJECTIVE: We sought to investigate the ability of whole-exome screening methods to detect disease-causing variants in patients with PIDDs. METHODS: Patients with PIDDs from 278 families from 22 countries were investigated by using whole-exome sequencing. Computational copy number variant (CNV) prediction pipelines and an exome-tiling chromosomal microarray were also applied to identify intragenic CNVs. Analytic approaches initially focused on 475 known or candidate PIDD genes but were nonexclusive and further tailored based on clinical data, family history, and immunophenotyping. RESULTS: A likely molecular diagnosis was achieved in 110 (40%) unrelated probands. Clinical diagnosis was revised in about half (60/110) and management was directly altered in nearly a quarter (26/110) of families based on molecular findings. Twelve PIDD-causing CNVs were detected, including 7 smaller than 30 Kb that would not have been detected with conventional diagnostic CNV arrays. CONCLUSION: This high-throughput genomic approach enabled detection of disease-related variants in unexpected genes; permitted detection of low-grade constitutional, somatic, and revertant mosaicism; and provided evidence of a mutational burden in mixed PIDD immunophenotypes.

A potential founder variant in CARMIL2/RLTPR in three Norwegian families with warts, molluscum contagiosum, and T-cell dysfunction.

BACKGROUND: Four patients from three Norwegian families presented with a common skin phenotype of warts, molluscum contagiosum, and dermatitis since early childhood, and various other immunological features. Warts are a common manifestation of human papilloma virus (HPV), but when they are overwhelming, disseminated and/or persistent, and presenting together with other immunological features, a primary immunodeficiency disease (PIDD) may be suspected. METHODS AND RESULTS: The four patients were exome sequenced as part of a larger study for detecting genetic causes of primary immunodeficiencies. No disease-causing variants were identified in known primary immunodeficiency genes or in other disease-related OMIM genes. However, the same homozygous missense variant in CARMIL2 (also known as RLTPR) was identified in all four patients. In each family, the variant was located within a narrow region of homozygosity, representing a potential region of autozygosity. CARMIL2 is a protein of undetermined function. A role in T-cell activation has been suggested and the mouse protein homolog (Rltpr) is essential for costimulation of T-cell activation via CD28, and for the development of regulatory T cells. Immunophenotyping demonstrated reduced regulatory, CD4+ memory, and CD4+ follicular T cells in all four patients. In addition, they all seem to have a deficiency in IFN γ -synthesis in CD4+ T cells and NK cells. CONCLUSIONS: We report a novel primary immunodeficiency, and a differential molecular diagnosis to CXCR4-,DOCK8-,GATA2-,MAGT1-,MCM4-,STK4-,RHOH-,TMC6-, and TMC8-related diseases. The specific variant may represent a Norwegian founder variant segregating on a population-specific haplotype.

Early Enhanced Parenteral Nutrition, Hyperglycemia, and Death Among Extremely Low-Birth-Weight Infants.

IMPORTANCE: Efforts to optimize early parenteral nutrition (PN) in extremely low-birth-weight (ELBW) infants to promote growth and development may increase hyperglycemia risk. Recent studies have identified an association between early hyperglycemia and adverse outcomes in ELBW infants. OBJECTIVES: To examine the prevalence of early hyperglycemia and clinical outcomes among ELBW infants before (2002-2005) and after (2006-2011) the implementation of an early enhanced PN protocol and to assess the independent effects of early enhanced PN and early hyperglycemia on mortality. DESIGN, SETTING, AND PARTICIPANTS: Observational cohort study in a level III neonatal intensive care unit. Prospectively collected clinical data in the neonatal intensive care unit's medical database, nutritional information, and blood glucose levels were merged for analysis. All ELBW infants born between January 1, 2002, and December 31, 2011, without lethal malformations and still alive at 12 hours of life were eligible for inclusion in the study. MAIN OUTCOMES AND MEASURES: Mortality was the main outcome measure. Severe hyperglycemia was defined as 2 consecutive blood glucose levels exceeding 216 mg/dL at least 3 hours apart. A multivariable logistic regression model was applied to determine the independent effects of early enhanced PN and hyperglycemia on mortality. RESULTS: In total, 343 infants were included in the study, 129 in a historical comparison group before the enhanced PN protocol and 214 in the early enhanced PN group. Baseline characteristics were similar between the study groups. After the introduction of early enhanced PN, the prevalence of severe hyperglycemia during the first week of life was higher in the early enhanced PN group (11.6% [15 of 129] vs 41.6% [89 of 214], P < .001), as was the mortality (10.9% [14 of 129] vs 24.3% [52 of 214], P = .003). When adjusting for background characteristics, treatment, and nutritional data, early severe hyperglycemia remained a strong independent risk factor for death (odds ratio, 4.68; 95% CI, 1.82-12.03), together with gestational age (odds ratio, 0.62; 95% CI, 0.49-0.79). CONCLUSIONS AND RELEVANCE: The implementation of an enhanced PN protocol was correlated with an increased prevalence of severe hyperglycemia and higher mortality. In the multivariable analysis, an enhanced PN regimen per se was not predictive of mortality, whereas early severe hyperglycemia remained strongly predictive of death. To avoid detrimental effects on outcomes in ELBW infants, the optimal composition of early PN to avoid postnatal growth failure must be carefully balanced against hyperglycemia risk.

A worrying trend in weight-adjusted paediatric antibiotic use in a Norwegian tertiary care hospital.

AIM: The World Health Organization recommends the defined daily dose (DDD) as the standard unit of measurement for antibiotic use, but this is not applicable in children. We aimed to assess paediatric antibiotic use in a Norwegian tertiary care hospital using a novel weight-adjusted method. METHODS: We obtained antibiotic purchase data from the hospital pharmacy and administrative data for all admissions from 2002 to 2009 to the paediatric wards at Oslo University Hospital, Rikshospitalet. Recommended daily doses per 100 kg days (RDDs/kg days) were calculated based on national guidelines for paediatric antibiotic use, length of stay and estimated weight for sex and age using national growth references. RESULTS: Total antibiotic use increased significantly from 51.8 to 65.5 RDDs/100 kg days. We found statistically significant annual increases in the consumption of carbapenems (18.0%), third-generation cephalosporins (6.0%) and imidazole derivatives (6.6%) and a considerable difference between total antibiotic use measured in RDDs/100 kg days and DDDs/100 bed days for neonates. CONCLUSION: Weight-adjusted antibiotic use provided a more meaningful description of the quantities of antibiotics consumed than DDDs/100 bed days, particularly for neonates. Total antibiotic use, use of meropenem, third-generation cephalosporins and imidazole derivatives increased significantly despite low prevalence of antibiotic-resistant pathogens.

Neonatal Levels of T-cell Receptor Excision Circles (TREC) in Patients with 22q11.2 Deletion Syndrome and Later Disease Features.

PURPOSE: Newborns with severe T-cell lymphopenia, including those with 22q11.2 deletion syndrome (DS), have low numbers of T-cell receptor excision circles (TRECs). The aim of this study was to determine a possible correlation between neonatal TRECs in 22q11.2DS and the development of different phenotypes to elucidate the prognostic value of TREC in this disease. METHODS: In this national survey including 46 patients with 22q11.2DS born after 2005, TREC levels were determined using stored newborn screening blood spots on filter cards. Patients were grouped into quartiles according to their TREC values, except the two infants with thymus aplasia. RESULTS: The two patients with thymic aplasia had no detectable TREC. The rest had no severe clinical immunodeficiency. There was a significant correlation between low TRECs and the proportion of patients with CD3(+)CD4(+)T-cells below the 5th percentile of healthy infants (p = 0.027) as well as the proportion with an abnormal thymus feature either no thymus or remnant thymus as observed during heart surgery (p = 0.022). Significantly lower TRECs (p = 0.019) were found in patients with cardiac defects compared to no such defects. Patients within the lowest quartile of TREC values (<71 TRECs/µL, n = 11) had more frequent severe cardiac defects than the other quartiles (p = 0.010). Eight of these patients in the lowest quartile needed an operation/intervention within two weeks after birth or died because of a cardiac defect. CONCLUSION: The low TREC values not only correlate with decreased T-cell immunity, but also with the occurrence of heart defects in the patients.

PGM3 mutations cause a congenital disorder of glycosylation with severe immunodeficiency and skeletal dysplasia.

Human phosphoglucomutase 3 (PGM3) catalyzes the conversion of N-acetyl-glucosamine (GlcNAc)-6-phosphate into GlcNAc-1-phosphate during the synthesis of uridine diphosphate (UDP)-GlcNAc, a sugar nucleotide critical to multiple glycosylation pathways. We identified three unrelated children with recurrent infections, congenital leukopenia including neutropenia, B and T cell lymphopenia, and progression to bone marrow failure. Whole-exome sequencing demonstrated deleterious mutations in PGM3 in all three subjects, delineating their disease to be due to an unsuspected congenital disorder of glycosylation (CDG). Functional studies of the disease-associated PGM3 variants in E. coli cells demonstrated reduced PGM3 activity for all mutants tested. Two of the three children had skeletal anomalies resembling Desbuquois dysplasia: short stature, brachydactyly, dysmorphic facial features, and intellectual disability. However, these additional features were absent in the third child, showing the clinical variability of the disease. Two children received hematopoietic stem cell transplantation of cord blood and bone marrow from matched related donors; both had successful engraftment and correction of neutropenia and lymphopenia. We define PGM3-CDG as a treatable immunodeficiency, document the power of whole-exome sequencing in gene discoveries for rare disorders, and illustrate the utility of genomic analyses in studying combined and variable phenotypes.

TTC7A mutations disrupt intestinal epithelial apicobasal polarity.

Multiple intestinal atresia (MIA) is a rare cause of bowel obstruction that is sometimes associated with a combined immunodeficiency (CID), leading to increased susceptibility to infections. The factors underlying this rare disease are poorly understood. We characterized the immunological and intestinal features of 6 unrelated MIA-CID patients. All patients displayed a profound, generalized lymphocytopenia, with few lymphocytes present in the lymph nodes. The thymus was hypoplastic and exhibited an abnormal distribution of epithelial cells. Patients also had profound disruption of the epithelial barrier along the entire gastrointestinal tract. Using linkage analysis and whole-exome sequencing, we identified 10 mutations in tetratricopeptide repeat domain­7A (TTC7A), all of which potentially abrogate TTC7A expression. Intestinal organoid cultures from patient biopsies displayed an inversion of apicobasal polarity of the epithelial cells that was normalized by pharmacological inhibition of Rho kinase. Our data indicate that TTC7A deficiency results in increased Rho kinase activity, which disrupts polarity, growth, and differentiation of intestinal epithelial cells, and which impairs immune cell homeostasis, thereby promoting MIA-CID development.

Dental developmental disturbances in 50 individuals with the 22q11.2 deletion syndrome; relation to medical conditions?

OBJECTIVE: The aims of the study were to examine tooth and enamel disturbances in individuals with 22q11.2 deletion syndrome and to analyze associations with medical conditions, birth characteristics and blood values of calcium and PTH. MATERIALS AND METHODS: Fifty individuals participated in the study (27 females, median age 10 years, range 1.5-44). Congenital absence of teeth was studied on orthopantomograms; 1148 teeth were examined, both clinically and radiologically, and enamel hypomineralizations and hypoplasias were recorded. Medical history and findings were recorded as part of a larger study on the manifestations of 22q11.2-deletion syndrome in Norway. RESULTS: Tooth agenesis was observed in 15% of study participants. Sixty-six percent of the participants and 26.0% of teeth presented with enamel disturbances. Of these, 12 individuals (24.0%) and 215 teeth (18.7%) had hypomineralizations and four individuals (8.0%) and 86 teeth (7.5%) had hypoplasias. Seventeen participants (34.0%) presented with both types of disturbance, but rarely in the same tooth. Only two teeth (0.17%) had both types of disturbance. Hypomineralizations were twice as frequent in permanent as in primary teeth. No correlations were found to medical conditions, except that participants with congenital cardiac anomalies presented with fewer total enamel disturbances and hypomineralizations in permanent teeth than those without. CONCLUSIONS: Enamel disturbances were frequently seen. There were more hypomineralizations than hypoplasias. Hypoparathyroidism and/or hypocalcemia are not clear etiological factors for enamel disturbances and there were no major correlations between medical conditions and enamel disturbances.

Hypoparathyroidism and autoimmunity in the 22q11.2 deletion syndrome.

OBJECTIVE: To characterize the endocrine and autoimmune disturbances with emphasis on parathyroid dysfunction in patients with 22q11.2 deletion syndrome (22q11.2 DS). Design In this nationwide survey; 59 patients (age 1-54 years) out of 86 invited with a 22q11.2 DS were recruited through all the genetic institutes in Norway. METHODS: Data was collected from blood tests, medical records, a physical examination and a semi-structured interview. We registered autoimmune diseases and measured autoantibodies, hormone levels and HLA types. RESULTS: Twenty-eight (47%) patients had hypoparathyroidism or a history of neonatal or transient hypocalcemia. Fifteen patients had neonatal hypocalcemia. Fourteen patients had permanent hypoparathyroidism including seven (54%) of those above age 15 years. A history of neonatal hypocalcemia did not predict later occurring hypoparathyroidism. Parathyroid hormone levels were generally low indicating a low reserve capacity. Twenty-eight patients were positive for autoantibodies. Six (10%) persons had developed an autoimmune disease, and all were females (P<0.02). Hypoparathyroidism correlated with autoimmune diseases (P<0.05), however, no antibodies were detected against the parathyroid glands. CONCLUSIONS: Hypoparathyroidism and autoimmunity occur frequently in the 22q11.2 DS. Neonatal hypocalcemia is not associated with later development of permanent hypoparathyroidism. Hypoparathyroidism may present at any age, also in adults, and warrants regular measurement of calcium levels. Hypoparathyroidism and autoimmunity occur frequently together. Our findings of autoimmune diseases in 10% of the patients highlight the importance of stringent screening and follow-up routines.