Molecular Identification of Inherited Diseases Flashcards
Genomic Imprinting
Enzymatic addition of methyl groups to specific nitrogen bases in a predicted pattern throughout the genome.
Congenital
Born with, referring to diseases with genetic components.
Lyon Hypothesis
Only one X chromosome remains genetically active in females. The other X chromosome is inactivated about the 16th day after embryonic development.
Barr Body
A structure visible in the interphase nucleus formed by the inactive X chromosome in female mammals.
Polyploidy
In diploid organisms, more than two of any autosome.
Nondisjunction
Abnormal separation of chromosomes during cell division resulting in both of a chromosome pair in one daughter cell.
Triploid
Having three of each chromosome.
Marker Chromosomes
An unknown chromosome or part of a chromosome of unknown origins.
Transmission Patterns
Mode of inheritance of a phenotype within a family.
Autosomal-dominant Transmission
A child of an infected individual and an unaffected male has a 50% to 100% risk or likelihood of expressing the disease phenotype.
X-linked
Sex-linked recessive. Having genetic components located on the X-chromosome.
3 main mendelian transmission patterns
Autosomal dominant, autosomal recessive, and X-linked.
Autosomal-dominant Transmission
An inheritance pattern where a child of an infected individual and an unaffected individual has a 50% to 100% risk or likelihood of expressing the disease phenotype.
Gain-of-function Mutation
The new properties of the mutant allele are responsible for the phenotype even in the presence of the normal allele. A phenotype having a new undesired trait.
Loss-of-function Mutation
A phenotype that is usually recessive, but it depends on the type of the protein affected.
Loss-of-function Mutation
A phenotype that is usually recessive, but it depends on the type of the protein affected.
Loss-of-function Mutation
A phenotype that is usually recessive, lacking a desired trait, but it depends on the type of the protein affected. In diploid organisms, inactivation of the normal allele is responsible for the phenotype.
Autosomal Recessive
Largest category of mendalian disorders. Recurrence risk is 25% if a sibling is affected, 50% for the child of an affected and unaffected individual, 100% for the child of two affected individuals.
Gonadal Mosaicism
The presence of more than one genotype in the germ cells of an individual.
New Mutations
A spontaneous mutation arising in germ cells of an unaffected individual.
Sex-linked Disorders
Having genetic components located on the X or Y chromosome.
Hemizygous
The presence of only one of two possible alleles in a diploid genotype.
Penetrance
The frequency of expression of disease phenotype in individuals with a gene lesion.
Cytochrome P-450
A group of enzymes localized to the endoplasmic reticulum.
Cytochrome P-450
A group of enzymes localized to the endoplasmic reticulum.
Autophagy
Degradation of intracellular substrates within the cell.
Heterophagy
Intercellular degradation of extracellular substrates taken into the cell by phagocytosis or endocytosis.
Cytochrome P-450
A group of enzymes localized to the endoplasmic reticulum that participates in enzymatic hydroxylation reactions and also transfers electrons to oxygen.
Gonadal Mosaicism
The presence of more than one genotype in the germ cells of an individual.
Premutations
A genetic lesion not manifesting a disease phenotype but prone to advance to full mutation/disease status.
Uniparental Disomy
Inheritance of chromosomal material from only one parent due to aberrant separation of chromosomes during meiosis.
