are monogenic traits a form of mutation
Type 1 and type 2 diabetes are both caused by mutations on multiple genes, making them polygenic. In monogenic forms, however, only one gene is responsible. That gene contains one or more mutations that inhibit the functioning of insulin-secreting pancreatic cells. Monogenic forms, caused by a single mutation in a dominantly or recessively inherited gene, are well-established, albeit relatively rare types of PD. They collectively account for about 30% of the familial and 3%–5% of the sporadic cases. Because only one gene is related to the development of diabetes, genetic testing via a blood sample can usually diagnose monogenic diabetes. Although genetic analysis can be expensive, it should be considered for people who show symptoms or traits that are inconsistent with their current diabetes diagnosis. People with monogenic forms of diabetes may not need the same types of treatment as people with type 1 or type 2. Some people with monogenic diabetes, for example, successfully manage their blood sugar with oral medications like sulfonylurea tablets, rather than with insulin injections. Three genes, each represented by a normal (dominant) and a mutant (recessive) allele, are on separate chromosomes and assort independently of one another. The F 2 of a cross of the homozygous (AA; BB; CC) normal strain with the triply mutant strain (aa; bb; cc) will produce 3/4 normal to 1/4 mutant for each character. Apart from the genes causing the six monogenic forms of PD, changes in a large number of additional genes were considered PD-causative and identified by linkage analysis or a candidate gene approach. Mutations in the LRRK2 gene are the most frequent known cause of late-onset autosomal-dominant and sporadic PD, with a mutation frequency ranging from 2% to 40% in different populations (Brice 2005; Lesage et al. Although only accounting for about 1 to 5 percent of young individuals with diabetes, this third type — referred to as monogenic forms of diabetes — can present with unique and, without an accurate diagnosis, puzzling symptoms. Parkin (PARK2). Parkin was the second identified PD gene and the first gene irrefutably causing an AR form of the disorder. The disease usually starts in the third or fourth decade of the patients’ life, and is usually slowly progressive with an excellent response to dopaminergic treatment. Abstract. Fifteen years of genetic research in Parkinson’s disease (PD) have led to the identification of several monogenic forms of the disorder and of numerous genetic risk factors increasing the risk to develop PD.
Yes