A Mendelian error in the genetic analysis of a species, describes an

allele An allele (, ; ; modern formation from Greek ἄλλος ''állos'', "other") is a variation of the same sequence of nucleotides at the same place on a long DNA molecule, as described in leading textbooks on genetics and evolution. ::"The chro ...

in an individual which could not have been received from either of its biological parents by

Mendelian inheritance Mendelian inheritance (also known as Mendelism) is a type of biological inheritance following the principles originally proposed by Gregor Mendel in 1865 and 1866, re-discovered in 1900 by Hugo de Vries and Carl Correns, and later popularize ...

. Inheritance is defined by a set of related individuals who have the same or similar

phenotype In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological pr ...

s for a locus of a particular gene. A Mendelian error means that the very structure of the inheritance as defined by analysis of the parental genes is incorrect: one parent of one individual is not actually the parent indicated; therefore the assumption is that the parental information is incorrect. Possible explanations for Mendelian errors are

genotyping Genotyping is the process of determining differences in the genetic make-up (genotype) of an individual by examining the individual's DNA sequence using biological assays and comparing it to another individual's sequence or a reference sequence. ...

errors, erroneous assignment of the individuals as relatives, or de novo mutations. Mendelian error is established by demonstrating the existence of a trait which is inconsistent with every possible combination of genotype compatible with the individual. This method of determination requires pedigree checking, however, and establishing a contradiction between phenotype and pedigree is an

NP-complete In computational complexity theory, a problem is NP-complete when: # it is a problem for which the correctness of each solution can be verified quickly (namely, in polynomial time) and a brute-force search algorithm can find a solution by trying ...

problem. Genetic inconsistencies which do not correspond to this definition are Non-Mendelian Errors. Statistical genetics analysis is used to detect these errors and to detect the possibility of the individual being linked to a specific disease linked to a single gene. Examples of such diseases in humans caused by single genes are

Huntington's disease Huntington's disease (HD), also known as Huntington's chorea, is a neurodegenerative disease that is mostly inherited. The earliest symptoms are often subtle problems with mood or mental abilities. A general lack of coordination and an uns ...

or Marfan syndrome.

Footnotes

Mendelian error detection in complex pedigree using weighted constraint satisfaction techniques
Genetics

error An error (from the Latin ''error'', meaning "wandering") is an action which is inaccurate or incorrect. In some usages, an error is synonymous with a mistake. The etymology derives from the Latin term 'errare', meaning 'to stray'. In statistics ...

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See also

Footnotes