Familial Aggregation Studies for Finding Risk Factors of Diseases: A Systematic Review

Familial aggregation studies are the first step for detecting the genetic causes of diseases, which compare the prevalence of a disease in families and general population. There are few studies regarding the definition and methods of familial aggregation studies. This study aims to review the familial aggregation studies to provide the details about the definition and methods of familial aggregation.
This systematic review was conducted in 2021. A search was first conducted in databases including Google Scholar, Cochrane library, Medline/PubMed, IranMedex, MagIran and SID using the keywords “familial” OR “family” and “aggregation” to find the related studies in Persian or English published until March 2021.

All studies in the field of familial aggregation were included in the study. Articles whose full texts was in a language other than Persian or English and those with insufficient information were excluded.

 The initial search yielded 461197 articles, of which 67 (0.015%) were found from the national databases. By examining the titles and abstracts, 138581 articles were excluded due to being duplicate and 322600 were excluded due to not providing an explanation about the methods. Finally, 7 articles were selected for the review.

 Familial aggregation studies are necessary for finding the genetic determinants of diseases which indicate the role of genetic and environment factors or their interactions in creating a specific phenotype.