Definitions Flashcards
(20 cards)
Genotype
The genetic constitution of an individual
Phenotype
The physical characteristics given the genotype and environment
Allele
One of several alternative forms of a gene at a locus
Polymorphism
Frequent hereditary variations of a gene found at a locus - doesn’t cause disease
Pathogenic variant
A genetic alteration that increases susceptibility to a disease
Consanguinity
Reproductive union between two relatives
Autozygosity
Homozygosity by hereditary descent I.e consanguinity
Variable expression
Variation in clinical features between individuals with the same gene alteration
Penetrance
The percentage of people who show the phenotype that have the genotype
Expressivity
The range of phenotypes expressed by a genotype
Anticipation
Increasingly worse symptoms through generations
-Huntingdonshire, mytonic dystrophy
Lyonisatio
X-inactivation in females
Hypomorphic mutation
Parents carry weak mutations which are then intensified to give the child the phenotype but not the parents
Alleic heterogenity
Different mutations cause one condition as oppose to allelic homogeneity
Locus heterogeneity
Genes at different loci can give the same condition
Point mutation
A mutation effecting one nucleotide in a gene sequence
Single nucleotide polymorphism
A variation in a single nucleotide
Homoplasmy
A eukaryotic cell which has identical copies of mitochondrial DNA
Heteroplasmy
Multiple copies of Mtdna in each cell
Single gene disorders
Equivalent to Mendelian disorders as oppose to chromosome abnormalities
