Case report: Diagnosis of ADCY5-related dyskinesia explaining the entire phenotype in a patient with atypical citrullinemia type I.

In this case study, we report the case of a 13-year-old girl with citrullinemia type 1 (MIM #215700), an autosomal recessive inherited disorder of the urea cycle, which was confirmed by the identification of a homozygous pathogenic variant in the argininosuccinate synthetase 1 (ASS1) gene. However, the patient presented abnormal hyperkinetic movements with global developmental delay and clinical signs that were not fully consistent with those of citrullinemia type 1 or with those of her siblings with isolated citrullinemia type 1. Exome sequencing showed the presence of a de novo heterozygous pathogenic variant in the adenylate cyclase type 5 (ADCY5) gene. The variant confirmed the overlap with the so-called ADCY5-related dyskinesia with orofacial involvement, which is autosomal dominant (MIM #606703), a disorder disrupting the enzymatic conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP). In addition to the citrullinemia-related low-protein diet and arginine supplementation, the identification of this second disease led to the introduction of a treatment with caffeine, which considerably improved the dyskinesia neurological picture. In conclusion, this case highlights the importance of clinical-biological confrontation for the interpretation of genetic variants, as one hereditary metabolic disease may hide another with therapeutic consequences. Summary: This article reports the misleading superposition of two inherited metabolic diseases, showing the importance of clinical-biological confrontation in the interpretation of genetic variants.

Epidemiological and clinical factors associated with post-exertional malaise severity in patients with myalgic encephalomyelitis/chronic fatigue syndrome.

BACKGROUND: Post-exertional malaise (PEM), the cardinal feature of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), occurs generally after exposure to a stressor. It is characterized by the worsening of ME/CFS symptoms and results in aggravating the course of the disease and the quality of life of patients. Due to its unpredictable onset, severity, and recovery time, identifying patients with higher risk for severe PEM would allow preventing or reducing its occurrence. We thus aimed at defining possible factors that could be associated with PEM severity. METHODS: Adult patients fulfilling ME international consensus criteria who attended the internal medicine department of University hospital Angers-France between October 2011 and December 2019 were included retrospectively. All patients were systematically hospitalized for an etiological workup and overall assessment. We reviewed their medical records for data related to the assessment: epidemiological data, fatigue features, clinical manifestations, and ME/CFS precipitants. PEM severity was appreciated by the Center for Disease Control self-reported questionnaire. The study population was classified into quartiles according to PEM severity scores. Analyses were performed with ordinal logistic regression to compare quartile groups. RESULTS: 197 patients were included. PEM severity was found to be positively associated with age at disease onset ≥ 32 years (OR 1.8 [95% CI 1.1-3.0] (p = 0.03)), recurrent infections during the course of the disease (OR 2.1 [95% CI 1.2-3.7] (p = 0.009)), and when ME/CFS was elicited by a gastrointestinal infectious precipitant (OR 5.7 [1.7-19.3] (p = 0.006)). CONCLUSION: We identified some epidemiological and clinical features, which were positively associated with PEM severity in subsets of ME/CFS patients. This could help improving disease management and patients' quality of life.

Effects of sildenafil on maximum walking time in patients with arterial claudication: The ARTERIOFIL study.

BACKGROUND: Patients with lower extremity peripheral artery disease (PAD) frequently experience claudication, a clinical symptom indicative of reduced walking capacity. Recommended care consists of exercise rehabilitation combined with optimal medical treatment and surgery. The effects of a single oral dose of sildenafil, a phosphodiesterase type-5 inhibitor, on patients with claudication are discussed. The aim of this study was to test the efficacy of a single 100 mg dose of sildenafil compared to placebo in terms of maximal walking time (MWT) in patients with claudication. METHODS: The ARTERIOFIL study is a crossover, double-blind, prospective, randomized, single-center study conducted at Angers University Hospital in France. MWT (primary endpoint) was assessed using a treadmill test (10% incline; 3.2 km/h). Secondary endpoints (pain-free walking time (PFWT), transcutaneous oximetry during exercise and redox cycle parameters and safety) were also studied. RESULTS: Fourteen patients were included of whom two were ultimately excluded. In the 12 remaining patients, the MWT was significantly improved during the sildenafil period compared with the placebo period (300 s [95% CI 172 s-428 s] vs 402 s [95% CI 274 s-529 s] p < 0.01). Sildenafil had no significant effect on pain-free walking time or skin tissue oxygenation during exercise. According to redox cycle parameters, sildenafil significantly reduced blood glucose and pyruvate levels and the 3-hydroxybutyrate/acetoacetate ratio, while there was no significant effect on lactate, 3-hydroxybutyrate, acetoacetate and free fatty acid levels. Symptomatic transient hypotension was observed in two women. CONCLUSIONS: The ARTERIOFIL study has shown that a single 100 mg oral dose of sildenafil had a significant effect on increase in MWT but had no significant effects on PFWT and oxygenation parameters in patients with claudication. A double-blind, prospective, randomized, multicenter study (VIRTUOSE©) is ongoing to evaluate the chronic effect of six month-long sildenafil treatment on MWT in PAD patients with claudication. CLINICAL TRIAL REGISTRATION: This clinical trial was registered at clinicaltrials.gov, registration. number: NCT02832570, (https://clinicaltrials.gov/ct2/show/NCT02832570).

Alagille syndrome: a case report.

We report the case of an infant hospitalized for neonatal anoxic ischemia in whom the diagnosis of Alagille syndrome (SAG ; MIM # 118450) was suspected in the presence of major cholestasis, cardiac malformations, suggestive facial dysmorphia, and vertebral and ocular abnormalities. This diagnosis was later confirmed by the detection of a heterozygous pathogenic variant in the gene JAG1, i.e. the gene predominantly responsible for this syndrome with autosomal dominant transmission, which affects about 1 in 30 000 births. The purpose of this presentation is to highlight this relatively unknown syndrome, both from the diagnostic and physiopathological points of view. This clinical case is also an opportunity to discuss pseudo-bisalbuminemia, accidentally discovered in the patient during the exploration of serum proteins by capillary electrophoresis. In total, the medical biologist is directly concerned by the multidisciplinary management of this syndrome, which involves biological perturbances in multiple organs.

A Plasma Metabolomic Signature Involving Purine Metabolism in Human Optic Atrophy 1 (OPA1)-Related Disorders.

Purpose: Dominant optic atrophy (DOA; MIM [Mendelian Inheritance in Man] 165500), resulting in retinal ganglion cell degeneration, is mainly caused by mutations in the optic atrophy 1 (OPA1) gene, which encodes a dynamin guanosine triphosphate (GTP)ase involved in mitochondrial membrane processing. This work aimed at determining whether plasma from OPA1 pathogenic variant carriers displays a specific metabolic signature. Methods: We applied a nontargeted clinical metabolomics pipeline based on ultra-high-pressure liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) allowing the exploration of 500 polar metabolites in plasma. We compared the plasma metabolic profiles of 25 patients with various OPA1 pathogenic variants and phenotypes to those of 20 healthy controls. Statistical analyses were performed using univariate and multivariate (principal component analysis [PCA], orthogonal partial least-squares discriminant analysis [OPLS-DA]) methods and a machine learning approach, the Biosigner algorithm. Results: A robust and relevant predictive model characterizing OPA1 individuals was obtained, based on a complex panel of metabolites with altered concentrations. An impairment of the purine metabolism, including significant differences in xanthine, hypoxanthine, and inosine concentrations, was at the foreground of this signature. In addition, the signature was characterized by differences in urocanate, choline, phosphocholine, glycerate, 1-oleoyl-rac-glycerol, rac-glycerol-1-myristate, aspartate, glutamate, and cystine concentrations. Conclusions: This first metabolic signature reported in the plasma of patient carrying OPA1 pathogenic variants highlights the unexpected involvement of purine metabolism in the pathophysiology of DOA.

Myoadenylate deaminase deficiency: a frequent cause of muscle pain A case detected by exercise testing.

Myoadenylate deaminase deficit (MAD, MIM#615511) is the most common cause of metabolic myopathies with an estimated prevalence of 1-2% in the general population. We report the case of a 39-year-old man suffering from severe skeletal muscle pain that had developed gradually for 4 years. A moderate increase in creatine kinase (CK) was the only biological sign observed. This study takes a closer look at a common but poorly known pathology and highlights the interest of the dynamic metabolic investigations carried out during exercise stress test with a cycle ergometer. Our non-invasive clinical and biological examination, at the interface between physiology and biology, disclosed the total absence of a physiological increase in plasma ammonia evocative of MAD. However, MAD was later confirmed by histochemistry and molecular studies, which revealed the presence of the recurrent homozygous pathogenic variant affecting the adenosine monophosphate deaminase 1 gene (AMPD1) in most patients with MAD.

Pituitary stalk interruption syndrome: a rare and severe cause of pituitary deficiency Laboratory diagnosis of a newborn case.

We report the case of a newborn with neonatal hypotonia associated to a micropenis and a bilateral cryptorchidia. The discovery of severe hypoglycemia at 0.22 mmol/L led to further biological investigations that revealed sharply decreased levels of several hypophyseal hormones. Altered corticotropic, somatotropic, thyreotropic, and gonadotropic axes finally suggested congenital hypophyseal insufficiency. This diagnostic was confirmed by a brain MRI (magnectic resonance imaging), which revealed a total interruption of the pituitary stalk. Immediate substitutive hormonal treatment allowed a clinical improvement of the condition and limited the risk of further episodes of hypoglycemia. The pituitary stalk interruption syndrome (PSIS), a very rare congenital disorder, has an estimated incidence of about 1:200.000. This developmental anomaly of the hypophysis calls for urgent diagnosis since prognosis depends on the rapid implementation of substitutive hormonal therapy. The hormonal deficit in the newborn affected by PSIS is often of a multiple nature with a constant somatotropic deficit, thus requiring the exploration of the different antehypophyseal axes. Despite the fact that PSIS is a rare disorder, it should always be kept in the differential diagnosis of newborn presenting with hypoglycemia. Since the interpretation of hormonal assays is particularly delicate at birth, close clinico-biological cooperation is essential for rapid diagnosis of PSIS and appropriate adaptation of the short- and long-term therapeutic management of the newborn.

Mitochondrial energetic defects in muscle and brain of a Hmbs-/- mouse model of acute intermittent porphyria.

Acute intermittent porphyria (AIP), an autosomal dominant metabolic disease (MIM #176000), is due to a deficiency of hydroxymethylbilane synthase (HMBS), which catalyzes the third step of the heme biosynthetic pathway. The clinical expression of the disease is mainly neurological, involving the autonomous, central and peripheral nervous systems. We explored mitochondrial oxidative phosphorylation (OXPHOS) in the brain and skeletal muscle of the Hmbs(-/-) mouse model first in the basal state (BS), and then after induction of the disease with phenobarbital and treatment with heme arginate (HA). The modification of the respiratory parameters, determined in mice in the BS, reflected a spontaneous metabolic energetic adaptation to HMBS deficiency. Phenobarbital induced a sharp alteration of the oxidative metabolism with a significant decrease of ATP production in skeletal muscle that was restored by treatment with HA. This OXPHOS defect was due to deficiencies in complexes I and II in the skeletal muscle whereas all four respiratory chain complexes were affected in the brain. To date, the pathogenesis of AIP has been mainly attributed to the neurotoxicity of aminolevulinic acid and heme deficiency. Our results show that mitochondrial energetic failure also plays an important role in the expression of the disease.

Pro-oxidant effect of ALA is implicated in mitochondrial dysfunction of HepG2 cells.

Heme biosynthesis begins in the mitochondrion with the formation of delta-aminolevulinic acid (ALA). In acute intermittent porphyria, hereditary tyrosinemia type I and lead poisoning patients, ALA is accumulated in plasma and in organs, especially the liver. These diseases are also associated with neuromuscular dysfunction and increased incidence of hepatocellular carcinoma. Many studies suggest that this damage may originate from ALA-induced oxidative stress following its accumulation. Using the MnSOD as an oxidative stress marker, we showed here that ALA treatment of cultured cells induced ROS production, increasing with ALA concentration. The mitochondrial energetic function of ALA-treated HepG2 cells was further explored. Mitochondrial respiration and ATP content were reduced compared to control cells. For the 300 µM treatment, ALA induced a mitochondrial mass decrease and a mitochondrial network imbalance although neither necrosis nor apoptosis were observed. The up regulation of PGC-1, Tfam and ND5 genes was also found; these genes encode mitochondrial proteins involved in mitochondrial biogenesis activation and OXPHOS function. We propose that ALA may constitute an internal bioenergetic signal, which initiates a coordinated upregulation of respiratory genes, which ultimately drives mitochondrial metabolic adaptation within cells. The addition of an antioxidant, Manganese(III) tetrakis(1-methyl-4-pyridyl)porphyrin (MnTMPyP), resulted in improvement of maximal respiratory chain capacity with 300 µM ALA. Our results suggest that mitochondria, an ALA-production site, are more sensitive to pro-oxidant effect of ALA, and may be directly involved in pathophysiology of patients with inherited or acquired porphyria.