Using medical exome sequencing to identify the causes of neurodevelopmental disorders: Experience of 2 clinical units and 216 patients.

Although whole-exome sequencing (WES) is the gold standard for the diagnosis of neurodevelopmental disorders (NDDs), it remains expensive for some genetic centers. Commercialized panels comprising all OMIM-referenced genes called "medical exome" (ME) constitute an alternative strategy to WES, but its efficiency is poorly known. In this study, we report the experience of 2 clinical genetic centers using ME for diagnosis of NDDs. We recruited 216 consecutive index patients with NDDs in 2 French genetic centers, corresponded to the daily practice of the units and included non-syndromic intellectual disability (NSID, n = 33), syndromic ID (NSID = 122), pediatric neurodegenerative disorders (n = 7) and autism spectrum disorder (ASD, n = 54). We sequenced samples from probands and their parents (when available) with the Illumina TruSight One sequencing kit. We found pathogenic or likely pathogenic variants in 56 index patients, for a global diagnostic yield of 25.9%. The diagnosis yield was higher in patients with ID as the main diagnosis (32%) than in patients with ASD (3.7%). Our results suggest that the use of ME is a valuable strategy for patients with ID when WES cannot be used as a routine diagnosis tool.

Wiedemann-Steiner syndrome as a major cause of syndromic intellectual disability: A study of 33 French cases.

Wiedemann-Steiner syndrome (WSS) is a rare syndromic condition in which intellectual disability (ID) is associated with hypertrichosis cubiti, short stature, and characteristic facies. Following the identification of the causative gene (KMT2A) in 2012, only 31 cases of WSS have been described precisely in the literature. We report on 33 French individuals with a KMT2A mutation confirmed by targeted gene sequencing, high-throughput sequencing or exome sequencing. Patients' molecular and clinical features were recorded and compared with the literature data. On the molecular level, we found 29 novel mutations. We observed autosomal dominant transmission of WSS in 3 families and mosaicism in one family. Clinically, we observed a broad phenotypic spectrum with regard to ID (mild to severe), the facies (typical or not of WSS) and associated malformations (bone, cerebral, renal, cardiac and ophthalmological anomalies). Hypertrichosis cubiti that was supposed to be pathognomonic in the literature was found only in 61% of our cases. This is the largest series of WSS cases yet described to date. A majority of patients exhibited suggestive features, but others were less characteristic, only identified by molecular diagnosis. The prevalence of WSS was higher than expected in patients with ID, suggesting than KMT2A is a major gene in ID.

Long-term follow-up and molecular characterization of a patient with a RECQL4 mutation spectrum disorder.

The follow-up of a man from birth to adulthood, presenting with features both of RAPADILINO and Rothmund-Thomson syndrome (RTS), is described. Molecular studies confirmed the presence of two different mutations, c.2767_2768delTT and c.3061C>T, in the RECQL4 gene. This gene is known to be causative of a spectrum including Baller-Gerold syndrome, RAPADILINO syndrome and RTS. New and rare features such as oral leukoplakia and very prominent hyperkeratotic verrucous papules on both soles are shown. This patient has to date no cancer history despite bearing a truncating mutation at the age of 21 years, which is also unusual.

Role of chromosomal imbalances in the pathogenesis of DSD: A retrospective analysis of 115 prenatal samples.

Differences of sex development (DSDs) are a group of congenital conditions characterized by a discrepancy between chromosomal, gonadal, and genital sex development of an individual, with significant impact on medical, psychological and reproductive life. The genetic heterogeneity of DSDs complicates the diagnosis and almost half of the patients remains undiagnosed. In this context, chromosomal imbalances in syndromic DSD patients may help to identify new genes implicated in DSDs. In this study, we aimed at describing the burden of chromosomal imbalances including submicroscopic ones (copy number variants or CNVs) in a cohort of prenatal syndromic DSD patients, and review their role in DSDs. Our patients carried at least one pathogenic or likely pathogenic chromosomal imbalance/CNV or low-level mosaicism for aneuploidy. Almost half of the cases resulted from an unbalanced chromosomal rearrangement. Chromosome 9p/q, 4p/q, 3q and 11q anomalies were more frequently observed. Review of the literature confirmed the causative role of CNVs in DSDs, either in disruption of known DSD-causing genes (SOX9, NR0B1, NR5A1, AR, ATRX, …) or as a tool to suspect new genes in DSDs (HOXD cluster, ADCY2, EMX2, CAMK1D, …). Recurrent CNVs of regulatory elements without coding sequence content (i.e. duplications/deletions upstream of SOX3 or SOX9) confirm detection of CNVs as a mean to explore our non-coding genome. Thus, CNV detection remains a powerful tool to explore undiagnosed DSDs, either through routine techniques or through emerging technologies such as long-read whole genome sequencing or optical genome mapping.

Noninvasive prenatal diagnosis of genetic diseases induced by triplet repeat expansion by linked read haplotyping and Bayesian approach.

The field of noninvasive prenatal diagnosis (NIPD) has undergone significant progress over the last decade. Direct haplotyping has been successfully applied for NIPD of few single-gene disorders. However, technical issues remain for triplet-repeat expansions. The objective of this study was to develop an NIPD approach for couples at risk of transmitting dynamic mutations. This method includes targeted enrichment for linked-read libraries and targeted maternal plasma DNA sequencing. We also developed an innovative Bayesian procedure to integrate the Hoobari fetal genotyping model for inferring the fetal haplotype and the targeted gene variant status. Our method of directly resolving parental haplotypes through targeted linked-read sequencing was smoothly performed using blood samples from families with Huntington's disease or myotonic dystrophy type 1. The Bayesian analysis of transmission of parental haplotypes allowed defining the genotype of five fetuses. The predicted variant status of four of these fetuses was in agreement with the invasive prenatal diagnosis findings. Conversely, no conclusive result was obtained for the NIPD of fragile X syndrome. Although improvements should be made to achieve clinically acceptable accuracy, our study shows that linked-read sequencing and parental haplotype phasing can be successfully used for NIPD of triplet-repeat expansion diseases.Trial registration: NCT04698551_date of first registration: 07/01/2021.

Duration of remission during maintenance cyclosporine therapy for psoriasis. Relationship to maintenance dose and degree of improvement during initial therapy.

BACKGROUND: Cyclosporine therapy is highly effective in the treatment of psoriasis. To minimize side effects, the lowest effective dosage for maintenance therapy should be sought. METHODS: We selected 61 patients who had achieved clearing or near-clearing of psoriasis during an induction phase of cyclosporine therapy. We then randomly assigned them in a double-blind fashion to receive one of two dosages of cyclosporine (1.5 or 3 mg/kg per day) or placebo for maintenance treatment. For each patient, the time to relapse was the time from the start of maintenance therapy until the patient showed a two-point worsening of psoriasis on a seven-point scale, up to a maximum of 4 months, when the study ended. RESULTS: Sixty patients completed the maintenance study. The mean time to relapse was significantly longer in the 3-mg/kg group (12 +/- 1 weeks) than in the 1.5-mg/kg group (9 +/- 1 weeks; P = .04) and the placebo group (7 +/- 1 weeks; P = .002); the latter two groups were not significantly different (P = .3). When the study ended, 57% of the 3-mg/kg group had not relapsed, compared with 21% and 5% of the 1.5-mg/kg and placebo groups, respectively. The following factors were associated with longer remissions: less psoriasis at the start of maintenance dosing (r = .40, P = .002); lower dosage of cyclosporine to achieve clearing or near-clearing during induction (r = -.30, P = .02); higher maintenance dosing (r = .38, P = .004); and smaller differences between the induction and maintenance dosages (r = -.41, P = .002). Patients' laboratory values improved compared with those at induction, and no patient experienced important clinical side effects during maintenance dosing. CONCLUSIONS: After clearing or near-clearing is achieved in patients with severe psoriasis, 3 mg/kg per day is a reasonable dosage to choose for maintenance. Patients who are more responsive to cyclosporine (as measured by greater clearing of psoriasis at lower induction dosages) tend to have longer remissions.

Mosquitoes and mosquito repellents: a clinician's guide.

This paper is intended to provide the clinician with the detailed and scientific information needed to advise patients who seek safe and effective ways of preventing mosquito bites. For this review, clinical and analytical data were selected from peer-reviewed research studies and review articles, case reports, entomology texts and journals, and government and industry publications. Relevant information was identified through a search of the MEDLINE database, the World Wide Web, the Mosquito-L electronic mailing list, and the Extension Toxicology Network database; selected U.S. Army, U.S. Environmental Protection Agency, and U.S. Department of Agriculture publications were also reviewed. N,N-diethyl-3-methylbenzamide (DEET) is the most effective, and best studied, insect repellent currently on the market. This substance has a remarkable safety profile after 40 years of worldwide use, but toxic reactions can occur (usually when the product is misused). When DEET-based repellents are applied in combination with permethrin-treated clothing, protection against bites of nearly 100% can be achieved. Plant-based repellents are generally less effective than DEET-based products. Ultrasonic devices, outdoor bug "zappers," and bat houses are not effective against mosquitoes. Highly sensitive persons may want to take oral antihistamines to minimize cutaneous reactions to mosquito bites.

Recurrent cutaneous vasculitis in cystic fibrosis.

We treated a patient with cystic fibrosis who experienced recurrent episodes of palpable purpura and arthralgias associated with exacerbations of her pulmonary disease. Skin biopsy demonstrated the classic findings of leukocytoclastic vasculitis, and C3 deposits were detected in the dermal blood vessels. Chronic bacterial infection and antibiotics are possible sources of antigen involved in immune complex formation in patients with chronic lung diseases.

Efficacy of cyclosporin A in psoriasis: a summary of the United States' experience.

Since its discovery in 1972, cyclosporin A (CyA) has been widely used in the experimental treatment of multiple inflammatory diseases considered to be of immune-mediated aetiology. In dermatology, oral CyA is most effective in the treatment of psoriasis and has been used successfully for plaque-type, pustular and erythrodermic forms of the disease. While dosages ranging from 1 to 14 mg/kg/day have been used, a starting dose of 4 mg/kg/day gives a rapid response with few side-effects. Nephrotoxicity remains the greatest concern in long-term use of the drug. Although intralesional CyA has proven effective in psoriasis, topical preparations have not. It is hoped that future research will provide effective topical formulations of CyA which are efficacious without the risks inherent in systemic administration.

Management of patients and side effects during cyclosporine therapy for cutaneous disorders.

Cyclosporine has been used in the experimental treatment of multiple inflammatory diseases of presumed autoimmune origin, including insulin-dependent diabetes mellitus, uveitis, rheumatoid arthritis, inflammatory bowel diseases, Graves' disease, and myasthenia gravis. In dermatology, the drug has been used successfully as primary therapy for psoriasis and psoriatic arthritis, alopecia areata, pyoderma gangrenosum, Behçet's disease, atopic dermatitis, and lichen planus. At a dose of 3 to 5 mg/kg per day, cyclosporine is well tolerated by most patients. However, because of concerns about its potential short- and long-term side effects, patients who use this drug require close monitoring. This review discusses appropriate clinical and laboratory evaluations, common and unusual side effects and their management, drugs that might alter the pharmacokinetics of cyclosporine metabolism, and criteria for dosage adjustments.

Oral cyclosporine for severe chronic idiopathic urticaria and angioedema.

Three patients with chronic urticaria, two of whom also had angioedema, were treated with oral cyclosporine, 6 mg/kg per day. In each patient, complete resolution of symptoms occurred within the first week of therapy; however, all patients eventually had to stop therapy as a result of side effects. On stopping therapy, all side effects resolved and the urticaria and angioedema recurred. Although cyclosporine therapy is not an appropriate treatment of urticaria, the results of this preliminary study suggest that cyclosporine and related drugs should be investigated in the treatment of mast cell-mediated diseases.

Regulation of adenylate cyclase and cyclic AMP phosphodiesterase by 5-hydroxytryptamine and calcium ions in blowfly salivary-gland homogenates.

Salivary-gland homogenates contain 5-hydroxytryptamine-stimulated adenylate cyclase. Half-maximal stimulation was obtained with 0.1 microM-5-hydroxytryptamine in the presence of added guanine nucleotides. Gramine antagonized the stimulation of cyclase caused by 5-hydroxytryptamine. In the presence of hormone, guanosine 5'-[gamma-thio]triphosphate produced a marked activation of adenylate cyclase activity. Stimulation of adenylate cyclase by forskolin or fluoride did not require the addition of guanine nucleotides or hormone. In the presence of EGTA, Ca2+ produced a biphasic activation of cyclase activity. Ca2+ at 1-100 microM increased activity, whereas 2000 microM-Ca2+ inhibited cyclase activity. The neuroleptic drugs trifluoperazine and chlorpromazine non-specifically inhibited adenylate cyclase activity even in the absence of Ca2+. The cyclic AMP phosphodiesterase activity in homogenates was not affected by Ca2+ or exogenous calmodulin. This enzyme was also inhibited by trifluoperazine in the absence of Ca2+. These results indicate that Ca2+ elevates adenylate cyclase activity, but had no effect on cyclic AMP phosphodiesterase of salivary-gland homogenates.

Cyclosporine for plaque-type psoriasis. Results of a multidose, double-blind trial.

BACKGROUND: Severe plaque-type psoriasis has been successfully treated with orally administered cyclosporine, but there has been no comparative, controlled evaluation of various dosages and their efficacy and side effects. METHODS: In a 16-week, double-blind trial, we randomly assigned 85 patients with severe psoriasis to receive 3, 5, or 7.5 mg of cyclosporine per kilogram of body weight per day or a placebo consisting of the vehicle for the drug. After eight weeks the dose could be adjusted to improve safety or efficacy while maintaining blinding. RESULTS: The psoriasis improved in a dose-dependent fashion. After eight weeks of fixed-dose therapy, 36, 65, and 80 percent of the patients receiving 3, 5, and 7.5 mg of cyclosporine per kilogram per day, respectively, were rated as being clear or almost clear of psoriasis; each group had significant improvement (P less than 0.0001) as compared with the group receiving vehicle, in which none of the patients were rated as clear or almost clear. The patients who received 5 mg per kilogram were the least likely to require dosage adjustments because of side effects or a lack of efficacy. The glomerular filtration rate, measured in a subgroup of 34 patients receiving cyclosporine, decreased by a median of 16 percent. Higher doses of cyclosporine had greater adverse effects on systolic blood pressure, glomerular filtration rate, and serum levels of creatinine, uric acid, bilirubin, and cholesterol. Delayed-type hypersensitivity reactions to skin-test antigens were reduced by cyclosporine administration. Cyclosporine appears to become concentrated in skin. CONCLUSIONS: Cyclosporine therapy leads to a rapid and thorough clearing of psoriasis; an initial dose of 5 mg per kilogram per day seems to be appropriate. However, the safety of cyclosporine for the long-term treatment of psoriasis remains to be determined.

A prospective study of renal structure and function in psoriasis patients treated with cyclosporin.

The impact of long-term cyclosporin therapy on kidney structure and function was evaluated in psoriasis patients with normal baseline renal function. Patients received cyclosporin at an average dose 3.9 mg/kg/day for up to three years and underwent serial kidney biopsies and measurements of iothalamate clearance and serum creatinine concentration. Kidney biopsy specimens (assessed on a scale of 0 to 4 where 0 = normal and 4 = severe) from 19 cyclosporin-treated patients as compared to 38 age-matched transplant donors showed increased interstitial fibrosis (1.9 +/- 0.2 vs. 0.3 +/- 0.1, P < 0.0001) and tubular atrophy (1.6 +/- 0.2 vs. 0.3 +/- 0.1, P < 0.0001) at one year. Eleven patients had a second biopsy after an additional two years of cyclosporin treatment demonstrating additional interstitial fibrosis (1.8 +/- 0.2 to 2.4 +/- 0.3, P = 0.002) and tubular atrophy (1.4 +/- 0.2 to 1.9 +/- 0.2, P = 0.053), and the onset of cyclosporin-associated arteriolopathy (0 to 0.5 +/- 0.2, P = 0.02). Quantitative digital morphometric analysis of trichrome-stained specimens also showed increased interstitial fibrosis (22.5 +/- 1.5 to 32.0 +/- 2.0% of interstitial area, P = 0.0008). Iothalamate clearance declined at an average rate of -3.1 ml/min/1.73 m2 per year (95% CI -5.8, -0.3) during the period of cyclosporin treatment. The slope of reciprocal serum creatinine declined by -0.06 dl/mg per year (95% CI -0.08, -0.04). Chronic cyclosporin treatment of otherwise healthy psoriasis patients is associated with progressive renal structural injury and reduced glomerular filtration rate.

Effects of cyclosporine on renal function in psoriasis patients.

Several prospective studies have documented the effectiveness of oral cyclosporine in the treatment of psoriasis. Despite this, the use of cyclosporine has been limited because of concern about the possibility of drug-induced renal dysfunction. We review the effects of cyclosporine on renal function.