Publications by authors named "Igor Raynouard"

3 Publications

  • Page 1 of 1

Heterozygous HTRA1 nonsense or frameshift mutations are pathogenic.

Brain 2021 Jul 16. Epub 2021 Jul 16.

AP-HP, Service de Génétique Moléculaire Neurovasculaire, Hôpital Saint-Louis, France.

Heterozygous missense HTRA1 mutations have been associated with an autosomal dominant cerebral small vessel disease whereas the pathogenicity of heterozygous HTRA1 stop codon variants is unclear. We performed a targeted high throughput sequencing of all known cerebral small vessel disease genes, including HTRA1, in 3,853 unrelated consecutive CSVD patients referred for molecular diagnosis. The frequency of heterozygous HTRA1 mutations leading to a premature stop codon in this patient cohort was compared with their frequency in large control databases. An analysis of HTRA1 messenger RNA was performed in several stop codon carrier patients. Clinical and neuroimaging features were characterized in all probands. Twenty unrelated patients carrying a heterozygous HTRA1 variant leading to a premature stop codon were identified. A highly significant difference was observed when comparing our patient cohort with control databases (gnomAD v3.1.1 (p = 3.12 x 10-17, OR = 21.9), TOPMed freeze 5 (p = 7.6 x 10-18, OR = 27.1) and 1000 Genomes (p = 1.5 x 10-5). Messenger RNA analysis performed in eight patients showed a degradation of the mutated allele strongly suggesting a haploinsufficiency. Clinical and neuroimaging features are similar to those previously reported in heterozygous missense mutation carriers, except for penetrance, which seems lower. Altogether, our findings strongly suggest that heterozygous HTRA1 stop codons are pathogenic through a haploinsufficiency mechanism. Future work will help to estimate their penetrance, an important information for genetic counseling.
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July 2021

Clinical Scales Do Not Reliably Identify Acute Ischemic Stroke Patients With Large-Artery Occlusion.

Stroke 2016 06 28;47(6):1466-72. Epub 2016 Apr 28.

From the Departments of Neurology (G.T., B.M., P.S., C.I., I.R., D.C., J.-C.B., J.-L.M.) and Radiology (O.N., M.T., M.E., C.O.), Hôpital Sainte-Anne, Paris, France; and Université Paris Descartes, Sorbonne Paris Cité, INSERM UMR S894, DHU Neurovasc, Paris, France (G.T., B.M., O.N., P.S., C.I., M.T., I.R., M.E., D.C., J.-C.B., J.-L.M., C.O.).

Background And Purpose: It remains debated whether clinical scores can help identify acute ischemic stroke patients with large-artery occlusion and hence improve triage in the era of thrombectomy. We aimed to determine the accuracy of published clinical scores to predict large-artery occlusion.

Methods: We assessed the performance of 13 clinical scores to predict large-artery occlusion in consecutive patients with acute ischemic stroke undergoing clinical examination and magnetic resonance or computed tomographic angiography ≤6 hours of symptom onset. When no cutoff was published, we used the cutoff maximizing the sum of sensitivity and specificity in our cohort. We also determined, for each score, the cutoff associated with a false-negative rate ≤10%.

Results: Of 1004 patients (median National Institute of Health Stroke Scale score, 7; range, 0-40), 328 (32.7%) had an occlusion of the internal carotid artery, M1 segment of the middle cerebral artery, or basilar artery. The highest accuracy (79%; 95% confidence interval, 77-82) was observed for National Institute of Health Stroke Scale score ≥11 and Rapid Arterial Occlusion Evaluation Scale score ≥5. However, these cutoffs were associated with false-negative rates >25%. Cutoffs associated with an false-negative rate ≤10% were 5, 1, and 0 for National Institute of Health Stroke Scale, Rapid Arterial Occlusion Evaluation Scale, and Cincinnati Prehospital Stroke Severity Scale, respectively.

Conclusions: Using published cutoffs for triage would result in a loss of opportunity for ≥20% of patients with large-artery occlusion who would be inappropriately sent to a center lacking neurointerventional facilities. Conversely, using cutoffs reducing the false-negative rate to 10% would result in sending almost every patient to a comprehensive stroke center. Our findings, therefore, suggest that intracranial arterial imaging should be performed in all patients with acute ischemic stroke presenting within 6 hours of symptom onset.
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June 2016