tailieunhanh - Chapter 062. Principles of Human Genetics (Part 22)

Inherited mitochondrial disorders are transmitted in a matrilineal fashion; all children from an affected mother will inherit the disease, but it will not be transmitted from an affected father to his children (Fig. 62-11D ). Alterations in the mtDNA affecting enzymes required for oxidative phosphorylation lead to reduction of ATP supply, generation of free radicals, and induction of apoptosis. Several syndromic disorders arising from mutations in the mitochondrial genome are known in humans and they affect both protein-coding and tRNA genes (Table 62-1 and Table 62-5). The broad clinical spectrum often involves (cardio)myopathies and encephalopathies because of the high dependence. | Chapter 062. Principles of Human Genetics Part 22 Inherited mitochondrial disorders are transmitted in a matrilineal fashion all children from an affected mother will inherit the disease but it will not be transmitted from an affected father to his children Fig. 62-11D . Alterations in the mtDNA affecting enzymes required for oxidative phosphorylation lead to reduction of ATP supply generation of free radicals and induction of apoptosis. Several syndromic disorders arising from mutations in the mitochondrial genome are known in humans and they affect both protein-coding and tRNA genes Table 62-1 and Table 62-5 . The broad clinical spectrum often involves cardio myopathies and encephalopathies because of the high dependence of these tissues on oxidative phosphorylation. The age of onset and the clinical course are highly variable because of the unusual mechanisms of mtDNA transmission which replicates independently from nuclear DNA. During cell replication the proportion of wild-type and mutant mitochondria can drift among different cells and tissues. The resulting heterogeneity in the proportion of mitochondria with and without a mutation is referred to as heteroplasmia and underlies the phenotypic variability that is characteristic of mitochondrial diseases. Table 62-5 Selected Mitochondrial Diseases Disease Syndrome OMIM MELAS syndrome mitochondrial myopathy with encephalopathy lactacidosis and stroke 540000 Leber s optic atrophy hereditary optical neuropathy 535000 Kearns-Sayre syndrome KSS ophthalmoplegia pigmental degeneration of the retina cardiomyopathy 530000 MERRF syndrome myoclonic epilepsy and ragged-red fibers 545000 Neurogenic muscular weakness with ataxia and retinitis pigmentosa NARP 551500 Progressive external ophthalmoplegia CEOP 258470 Pearson syndrome PEAR bone marrow and pancreatic failure 557000 Autosomal dominant inherited mitochondrial myopathy with mitochondrial deletion ADMIMY 157640 Somatic mutations in cytochrome b gene exercise .

• Y học thường thức
• Principles of Human Genetics
• bệnh học và điều trị
• bài giảng bệnh học
• tài liệu y khoa
• Harrisons Internal Medicine
• Biological information
• Lecture Genetics
• Human genetics
• Modern genetic techniques
• Mendels principles
• Mendels principles of heredity