Mendelian error
Encyclopedia
A Mendelian error in the genetic
analysis of a species, describes an allele
in an individual which could not have been received from either of its biological parents by Mendelian inheritance
. Inheritance is defined by a set of related individuals who have the same or similar phenotype
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.
The possible explanations are multiple and can be due to experimental genotyping
errors or to the erroneous assignment of the individuals as relatives. 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
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
or Marfan syndrome
.
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
analysis of a species, describes an allele
Allele
An allele is one of two or more forms of a gene or a genetic locus . "Allel" is an abbreviation of allelomorph. Sometimes, different alleles can result in different observable phenotypic traits, such as different pigmentation...
in an individual which could not have been received from either of its biological parents by Mendelian inheritance
Mendelian inheritance
Mendelian inheritance is a scientific description of how hereditary characteristics are passed from parent organisms to their offspring; it underlies much of genetics...
. Inheritance is defined by a set of related individuals who have the same or similar phenotype
Phenotype
A phenotype is an organism's observable characteristics or traits: such as its morphology, development, biochemical or physiological properties, behavior, and products of behavior...
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.
The possible explanations are multiple and can be due to experimental genotyping
Genotyping
Genotyping is the process of determining differences in the genetic make-up 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. It reveals the alleles an individual has inherited from their...
errors or to the erroneous assignment of the individuals as relatives. Mendelian error is established by demonstrating the existence of a trait which is inconsistent with every possible combination of genotype
Genotype
The genotype is the genetic makeup of a cell, an organism, or an individual usually with reference to a specific character under consideration...
compatible with the individual. This method of determination requires pedigree checking, however, and establishing a contradiction between phenotype and pedigree is an NP-complete
NP-complete
In computational complexity theory, the complexity class NP-complete is a class of decision problems. A decision problem L is NP-complete if it is in the set of NP problems so that any given solution to the decision problem can be verified in polynomial time, and also in the set of NP-hard...
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
Huntington's disease, chorea, or disorder , is a neurodegenerative genetic disorder that affects muscle coordination and leads to cognitive decline and dementia. It typically becomes noticeable in middle age. HD is the most common genetic cause of abnormal involuntary writhing movements called chorea...
or Marfan syndrome
Marfan syndrome
Marfan syndrome is a genetic disorder of the connective tissue. People with Marfan's tend to be unusually tall, with long limbs and long, thin fingers....
.