Mutations in plasmalemma vesicle-associated protein cause severe syndromic protein-losing enteropathy

BackgroundProtein-losing enteropathy (PLE) is characterised by gastrointestinal protein leakage due to loss of mucosal integrity or lymphatic abnormalities. PLE can manifest as congenital diarrhoea and should be differentiated from other congenital diarrhoeal disorders. Primary PLEs are genetically heterogeneous and the underlying genetic defects are currently emerging.ObjectivesWe report an infant with fatal PLE for whom we aimed to uncover the underlying pathogenic mutation.MethodsWe performed whole exome sequencing (WES) for the index patient. Variants were classified based on the American College of Medical Genetics and Genomics guidelines. WES results and our detailed clinical description of the patient were compared with the literature.ResultsWe discovered a novel homozygous stop mutation (c.988C>T, p.Q330*) in the Plasmalemma Vesicle-Associated Protein (PLVAP) gene in a newborn with fatal PLE, facial dysmorphism, and renal, ocular and cardiac anomalies. The Q330* mutation is predicted to result in complete loss of PLVAP protein expression leading to deletion of the diaphragms of endothelial fenestrae, resulting in plasma protein extravasation and PLE. Recently, another single homozygous stop mutation in PLVAP causing lethal PLE in an infant was reported.ConclusionsOur findings validate PLVAP mutations as a cause of syndromic PLE. Prenatal anomalies, severe PLE and syndromic features may guide the diagnosis of this rare disease.

Role of Calcitonin Gene Related Peptide (CGRP) in Migraine

Migraine is the second most primary headache. The prevalence of Migraine is 12% in the general population, including 18% in women and 6% in men. Migraine can start in childhood and adolescence and continue throughout lifespan. It is most prevalent among people in their 30s and 40s. Migraine is a debilitating hemicranial headache that is pulsating, aggravated by movement, nausea, vomiting and having sensitivity to light and sound, with or without aura. It can affect all aspects of life as work and school, parenting and family relationships and personal and leisure time. There are some theory regarding pathogenesis of migraine which includes cortical spreading depression, cortical spreading oligemia, activation of trigeminocervical complex leading to neuroinflammation & release of vasodialating neuropeptides which include calcitonin gene related peptide (CGRP), substance P, vasoactive intestinal polypeptide (VIP), nitric oxide (NO), and pituitary adenylate cyclase activating peptide (PACAP) & genetic factor. CGRP is a potent vasodilator and causes perivascular plasma protein extravasation and nociceptive pain. Newer medications target CGRP both for acute and preventive treatment of migraine. Bangladesh Journal of Neuroscience 2017; Vol. 33 (1): 39-43

Putative role of 5-HT2B receptors in migraine pathophysiology

Objective In this review we attempt to characterize the acute and chronic role of 5-HT2B receptors with regard to meningeal nociception in animal experiments and clinical data targeting migraine therapy. Background Migraine is a common disabling neurovascular primary headache disease, the pathomechanism of which is still unclear. Serotonin (5-HT) and its receptors might play an important role in some aspects of migraine pathogenesis. The ability of the unselective 5-HT2B receptor agonist m-chlorophenylpiperazine to induce migraine attacks in migraine sufferers, the high affinity of prophylactic antimigraine drugs to this receptor and its expression in migraine-relevant structures like the dura mater argue for a role of 5-HT2B receptors in the pathogenesis of migraine attacks. Methods For this review, the relevant databases such as PubMed, MEDLINE®, Cochrane Library and EMBASE, respectively, were searched to December 2015 using the keywords “migraine, 5-HT2, trigeminal, neurogenic inflammation, nitric oxide, nitroxyl, vasodilatation, plasma protein extravasation” and combinations thereof. Conclusion Our literature review suggests an important role of 5-HT2B receptor activation in meningeal nociception and the generation of migraine pain.