A large number of diseases have been grouped together as ‘rare diseases’, because we do not know much about them. There is no consensus on the definition of a rare disease. This is because, obtaining reliable statistical estimates of the frequency of occurrence of a rare event, such as prevalence of a rare disease, requires an inordinately large sample size, collection of which costs prohibitively large amount of money. (Editorial)
Original Source [2]
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/rare-diseases-need-our-attention
[2] http://www.currentscience.ac.in/Volumes/111/01/0007.pdf
[3] http://admin.indiaenvironmentportal.org.in/category/author/v-m-katoch-0
[4] http://admin.indiaenvironmentportal.org.in/category/author/p-p-majumder
[5] http://admin.indiaenvironmentportal.org.in/category/author/bhattacharya
[6] http://admin.indiaenvironmentportal.org.in/category/journal/current-science
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/diseases
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/medical-research
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/india
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/drugs
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/diagnostic-methods