A rare case report on novel pathogenic mutation of TSC2 gene explained at molecular level

Tuberous sclerosis is a neurocutaneous genetic syndrome inherited as autosomal dominant pattern. This disease is caused by mutations of either of the tumor suppressor genes named TSC1 or TSC2 gene. It encodes for hamartin and tuberinwhich modulates mTOR pathway and regulate cell growth and proliferation. We report a case of a 7 year old child positive for pathogenic variant of TSC2 mutation having multiple seizures, angiofibromas, shagreen patch. Imaging studies are indicative of multiple calcified nodules in sub ependymal region, abnormal subcortical white matter suggestive of tuberous sclerosis. Molecular tests suggested that the mutation occurred results in alteration of splicing mechanism. Due to such alteration, the incomplete TSC2 gene encodes an altered tuberin protein i.e., unable to interact with Ras homologue enriched in brain (Rheb), leading to dysregulation of mammalian target of rapamycin (mTOR) signalling causing tuberous sclerosis disease.

The role of hamartin in ischemia/hypoxia tolerance / 中国比较医学杂志

Hypoxia/ischemia is a common clinical pathophysiological process and cause of death,and it is a common problem in extreme conditions such as high altitude,astronautics and diving.Hamartin is a kind of effective endogenous neuroprotectant and could increase cell tolerance to acute hypoxia or ischemia, thus,is of significance to research.The role of hamartin in hypoxia/ischemia has been a research focus of many scientists.Elucidating the related protective effect and its DNA methylation on hypoxia/ischemia can not only reduce injury,but also lay a basic for further studying the role of hamartin and its DNA methylation in other pathophysiological processes and provide theoretical guidance for the following clinical study.In this paper,we review the structure,mechanism and role of hamartin and the effect of its DNA methylation on hypoxia/ischemia.