Non-paternity event

Non-paternity event is a term in genetic genealogy and clinical genetics to describe the case where the biological father of a child is someone other than who it is presumed to be. The presumption may be either on the part of the presumed father or by the physician. Non-paternity may result from a number of different scenarios: it may arise from sperm donation or when the mother had sexual intercourse with a man other than the presumed father. Other than the situation of egg donation, the identity of a child's mother is seldom in doubt.^[1] Non-paternity (and non-maternity) may also result from hidden adoptions: that is, when a child is never told he or she was adopted. Where there is uncertainty, then the only definitive diagnosis of non-paternity is from DNA testing.

The discovery of previously unsuspected or undisclosed non-paternity may have both social and medical consequences. Non-paternity that is due to a previously undisclosed extra-marital relationship will have obvious consequences for the marital relationship which it violates. Non-paternity is medically relevant when interpreting the results and utility of genetic screening for hereditary illnesses such as cystic fibrosis.^[1]

In genetic genealogy the term NPE is often used in a wider context to indicate a break in the link between the Y-chromosome and the surname. Such a breakage may occur because of illegitimacy (inside or outside of marriage), the use of an alias, or a deliberate change of surname.

Testing for non-paternity

Further information: Parental testing

The only definitive test for paternity is DNA testing. Requirements for consent and counselling for DNA testing vary by country.

Rates of non-paternity

The rate of non-paternity is commonly quoted to be around 10%.^[1][2][3] However, a 2005 scientific review of international published studies of paternal discrepancy found a range in incidence from 0.8% to 30% (median 3.7%), suggesting that the widely quoted figure of 10% of non-paternal events is an overestimate. In situations where disputed parentage was the reason for the paternity testing, there were higher levels; an incidence of 17% to 33% (median of 26.9%). Most at risk of parental discrepancy were those born to younger parents, to unmarried couples and those of lower socio-economic status, or from certain cultural groups.^[4]

The rates value varies according to the population studied:

• United Kingdom: 1 to 2% in a sample of 1,678 men.^[5]
• Mexico: 9.8% to 13.8% in a sample of 396 children.^[6]
• Switzerland: 0.3% to 1.3%.^[7]
• United States: A study in Michigan of 1417 white and 523 black children found non-paternity rates of 1.4% and 10.1% respectively.^[8] A study of 1748 Hawaiian families with 2839 children reported a non-paternity rate of 2 to 3%.^[9]

See also

• Paternity fraud

References

1. ^ ^{a b c} Macintyre S and Sooman A (1991). "Non-paternity and prenatal genetic screening". Lancet 338 (8771): 869–871. doi:10.1016/0140-6736(91)91513-T. PMID 1681226. 
2. ^ Neale MC, Neale BM, Sullivan PF (2002). "Nonpaternity in linkage studies of extremely discordant sib pairs". Am J Hum Genet 70 (2): 526–529. doi:10.1086/338687. PMC 384925. PMID 11745068. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=384925. 
3. ^ Rincon P (11 February 2009). "Study debunks illegitimacy 'myth'". BBC News. http://news.bbc.co.uk/2/hi/science/nature/7881652.stm. Retrieved 11 February 2009. 
4. ^ Bellis MA, Hughes K, Hughes S, Ashton JR (September 2005). "Measuring paternal discrepancy and its public health consequences". J Epidemiol Community Health 59 (9): 749–54. doi:10.1136/jech.2005.036517. PMC 1733152. PMID 16100312. http://jech.bmj.com/cgi/pmidlookup?view=long&pmid=16100312. 
5. ^ King TE and Jobling MA (2009). "Founders, drift and infidelity: the relationship between Y chromosome diversity and patrilineal surnames". Mol Biol Evol 26 (5): 1093–102. doi:10.1093/molbev/msp022. PMC 2668828. PMID 19204044. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2668828. 
6. ^ Cerda-Flores RM, Barton SA, Marty-Gonzalez LF, Rivas F, Chakraborty R (1999). "Estimation of nonpaternity in the Mexican population of Nuevo Leon: A validation study with blood group markers". Am J Physical Anthropol 109 (3): 281–293. doi:10.1002/(SICI)1096-8644(199907)109:3<281::AID-AJPA1>3.0.CO;2-3. PMID 10407460. 
7. ^ Sasse G, Müller H, Chakraborty R, Ott J (1994). "Estimating the frequency of nonpaternity in Switzerland". Hum Hered 44 (6): 337–43. doi:10.1159/000154241. PMID 7860087. 
8. ^ Schacht LE, Gershowitz H (1963). "Frequency of extra-marital children as determined by blood groups". In Gedda L. Proceedings of the Second International Congress on Human Genetics (Rome, Sept 6–12, 1961). Rome: G Mendel. pp. 894–97. 
9. ^ Ashton GC (1980). "Mismatches in genetic markers in a large family study". Am J Hum Genet 32 (4): 601–13. PMID 6930820. 

External links

• NPE's and Their Resolution