EtymologyLearned borrowing from consanguineosus (with English -ous), from cum meaning "together" + sanguineus meaning "of or pertaining to blood", derived from sanguis meaning "blood"
- Related by birth;
descended from the same
parent or ancestor.
- 2002, B. Modell and A. Darr, "Science and society: genetic
counselling and customary consanguineous marriage," Nature Reviews:
Genetics, vol 3. no. 3 (Mar.), p. 225,
- Consanguineous marriage is customary in many societies, but leads to an increased birth prevalence of infants with severe recessive disorders.
- 2002, B. Modell and A. Darr, "Science and society: genetic counselling and customary consanguineous marriage," Nature Reviews: Genetics, vol 3. no. 3 (Mar.), p. 225,
Consanguinity ("con- (with) sanguine (blood) -ity") refers to the property of being from the same lineage as another person. In that respect, consanguinity is the quality of being descended from the same ancestor as another person. Consanguinity is an important legal concept in that the laws of many jurisdictions consider consanguinity as a factor in deciding whether two individuals may be married or whether a given person receives property when a deceased person has not left a will.
The degree of relative consanguinity can be illustrated with a consanguinity table, in which each level of lineal consanguinity (i.e., generation) appears as a row, and individuals with a collaterally-consanguineous relationship share the same row. See, e.g., table of consanguinity.
Legal definitionsIn regard to family law, generally, consanguinity becomes important in defining who may marry. Some states forbid cousins to marry. Others are more lenient and only forbid people to marry their brothers, sisters, mothers, fathers, or aunts and uncles. On a related note, many states prevent individuals from serving on a jury in which they have a certain degree of consanguinity with the defendant.
Several volumes of Smith's Laws, enacted from 1700 through 1829, contain certain public and private laws of the Province and Commonwealth of Pennsylvania. Several laws with a prescribed punishment against adultery, bigamy, incest and fornication and all combinations of those crimes were enacted in 1705. They are found in volume I of Smith's Laws along with a table of Degrees of consaguinity and affinity http://www.palrb.us/smithlaws/17001799/1705/0/act/0122.pdf.
In regard to the law of intestate succession (when a person dies without a will), under the Uniform Probate Code of the United States section 2-103, after a surviving spouse receives his or her share, the descendants (depending on the circumstances this may include children, grandchildren, or great grandchildren, either biological or adopted) receive the remainder of the intestate estate. If there are no children, the decedent's parent(s) receive the remainder of the estate. If there are neither descendants nor parents, the decedent's estate is distributed to descendants of the decedent's parents (again, depending on the circumstances, brothers and sisters, nieces and nephews, grand nieces and nephews and great grand nieces and nephews). If there are no descendants, parents, or descendants of parents, then the deceased's property passes to descendants of the grandparents of the decedent's (uncles and aunts, first cousins, or first cousins once, twice, or thrice removed).
The connotations of degree of consanguinity varies by context (e.g., Canon law, Roman law, etc.). Most cultures define a degree of consanguinity within which sexual interrelationships are regarded as incestuous (the "prohibited degree of kinship"). In the Roman Catholic Church, unwittingly marrying a closely-consanguineous blood relative is grounds for an annulment, but dispensations were granted, actually almost routinely (the Catholic Church's ban on marriage within the fourth degree of relationship (first cousins once removed) lasted from 1550 to 1917; before that, the prohibition applied to marriages within the seventh degree of kinship).
Adoption may or may not be considered at law to create such a bond; in most Western societies, adoptive relationships are considered blood relationships for these purposes, but in others, including both Japan and ancient Rome, it was common for a couple with only daughters to adopt a son-in-law, making the marriage one between adoptive siblings.
Among the Christian Habesha highlanders of Ethiopia and Eritrea (the predominantly orthodox Christian Amhara and Tigray-Tigrinya), it is a tradition to be able to recount one's paternal ancestors at least 7 generations away starting from early childhood, because "those with a common patrilineal ancestor less than seven generations away are considered 'brother and sister' and may not marry." The rule is less strict on the mother's side, where the limit is about four generations back, but still determined patrilinearly. This rule does not apply to Muslims or other ethnic groups.
Rates of occurrenceHistorically, some European nobles cited a close degree of consanguinity when they required convenient grounds for divorce, especially in contexts where religious doctrine forbade the voluntary dissolution of an unhappy or childless marriage. Conversely, the consanguinity law of succession requires the next monarch to be of the same blood of the previous one; allowing, for example, illegitimate children to inherit. It is estimated that 55% of marriages between Punjabi Pakistani immigrants in the United Kingdom are between first cousins, where "preferential patrilateral parallel cousin marriage" (where a boy marries his father's brother's daughter) is often favored.
The offspring of consanguinous relationships are at greater risk of certain genetic disorders. Autosomal recessive disorders occur in individuals who are homozygous for a particular recessive gene mutation. This means that they carry two copies (alleles) of the same gene. Except in certain rare circumstances (new mutations or uniparental disomy) both parents of an individual with such a disorder will be carriers of the gene. Such carriers are not affected and will not display any signs that they are carriers, and so may be unaware that they carry the mutated gene. As relatives share a proportion of their genes, it is much more likely that related parents will be carriers of an autosomal recessive gene, and therefore their children are at a higher risk of an autosomal recessive disorder. The extent to which the risk increases depends on the degree of genetic relationship between the parents; so for incestuous relationships where the parents share 1/2 of their DNA the risk is great, but for relationships between second cousins where the parents only share 1/32 of their DNA the risk is less (although still greater than the general population).
- Kingston H M, "ABC of Clinical Genetics", Pages 7 & 26-27, 3rd Edition (2002), BMJ Books, London, 0-7279-1627-0
- Kalmes, Robert and Jean-Loup Huret. "Consanguinity." - Includes detailed information on the application of the coefficient of consanguinity
- Burtsell, Richard L. "Consanguinity (in Canon Law)." The Catholic Encyclopedia.
- Consanguinity from GeneWeb
consanguineous in German: Blutsverwandtschaft
consanguineous in French: Consanguinité
consanguineous in Lithuanian: Kraujo giminystė
consanguineous in Dutch: Bloedverwantschap
consanguineous in Japanese: 血縁
consanguineous in Polish: Pokrewieństwo
consanguineous in Portuguese: Consanguinidade
consanguineous in Serbian: Укрштање у сродству
consanguineous in Swedish: Blodsförvantskap
consanguineous in Chinese: 血親