A founder variant is a pathogenic variant observed at high frequency in a specific population due to the presence of the variant in a single ancestor or small number of ancestors. The presence of a founder variant can affect the approach to molecular genetic testing. When one or more founder variants account for a large percentage of all pathogenic variants found in a population, testing for the founder variant(s) may be performed first.
The table below includes common founder variants – here defined as three or fewer variants that account for >50% of the pathogenic variants identified in a single gene in individuals of a specific ancestry – in individuals of Georgian Jewish ancestry. Note: Pathogenic variants that are common worldwide due to a DNA sequence hot spot are not considered founder variants and thus are not included.
Table.
Genetic Disorders Associated with Founder Variants Common in the Georgian Jewish Population
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Included if ≤3 pathogenic variants account for ≥50% of variants identified in a specific ethnic group
- 1.
Percentage does not account for the possibility of rare de novo pathogenic variants occurring in this population.
- 2.
To date, no additional pathogenic variants in this gene have been reported in individuals of this ethnicity.
References
Hashem H, Kelly SJ, Ganson NJ, Hershfield MS. Deficiency of adenosine deaminase 2 (DADA2), an inherited cause of polyarteritis nodosa and a mimic of other systemic rheumatologic disorders.
Curr Rheumatol Rep. 2017;19:70. [
PubMed: 28983775]
Mei-Zahav M, Stafler P, Senderowitz H, Bentur L, Livnat G, Shteinberg M, Orenstein N, Bazak L, Prais D, Levine H, Gur M, Khazanov N, Simhaev L, Eliyahu H, Cohen M, Wilschanski M, Blau H, Mussaffi H. The Q359K/T360K mutation causes cystic fibrosis in Georgian Jews.
J Cyst Fibros. 2018;17:e41–e45. [
PubMed: 30033373]
