Genealogical data in population medical genetics: field guidelines

Abstract

This is a guide for fieldwork in Population Medical Genetics research projects. Data collection, handling, and analysis from large pedigrees require the use of specific tools and methods not widely familiar to human geneticists, unfortunately leading to ineffective graphic pedigrees. Initially, the objective of the pedigree must be decided, and the available information sources need to be identified and validated. Data collection and recording by the tabulated method is advocated, and the involved techniques are presented. Genealogical and personal information are the two main components of pedigree data. While the latter is unique to each investigation project, the former is solely represented by gametic links between persons. The triad of a given pedigree member and its two parents constitutes the building unit of a genealogy. Likewise, three ID numbers representing those three elements of the triad is the record field required for any pedigree analysis. Pedigree construction, as well as pedigree and population data analysis, varies according to the pre-established objectives, the existing information, and the available resources.

Mosaicism in Fragile X syndrome: A family case series

“…Ethical approval (Universidad del Valle, approval number 016-014) for the protocol and informed consents for photographs and clinical data for publication where obtained from all of the study subjects. Medical history was obtained from all family members and a pedigree was constructed using the methodology proposed by Coffee et al (2008) and Poletta et al (2014) and Progeny 9 Clinical tool software. Finally screening for FXS FMR1 gene mutation was done in 502 males and 424 females (Saldarriaga et al, 2018).…”

Differential expression of the IRF6 gene in the signs of Van der Woude Syndrome: Are distinct genetic modifiers operating?

“…To obtain genealogical data, the tabulated pedigree method according to Polleta et al (2014) [17] was used. The graphical construction of the pedigree was performed using an online tool from the Progeny program, available at: www.progenygenetics.com.…”

Blood is thicker than bloodshed: A genealogical approach to reconstruct populations after armed conflicts

“…Outside the social sciences, population genetics has produced the most systematic and up-to-date protocols for collecting primary genealogies (Poletta, Orioli, and Castilla 2014;Williams-Blangero and Blangero 2006). However, these guidelines were designed for studying genetic inheritance, not demographic processes.…”

“…59% of the interviews were answered by a single respondent, and 68% were completed in a single visit to the household. Interviews with women and couples were preferred, since they are known to provide more accurate genealogical accounts than interviews conducted exclusively with men (Poletta, Orioli, and Castilla 2014). The interviews carried out in Río Negro included women in 50% of the cases.…”