Genetics Flashcards
mostly defintions
What is Aneuploidy?
having an abnormal number of chromosomes
What is Autosomal Dominance?
manifests in the heterozygous state - affects both sexes equally
What is Autosomal Recessive?
manifests only in the homozygous state - affects both sexes equally
What is Allelic Homogeneity?
When all individuals with a disease have the same mutation (Huntington’s)
What is Allelic Polymorphism?
When more than one allele can be found for a given gene within the normal population
What is Allelic Heterogeneity?
When different mutations on the same gene result in the same condition forming (cystic fibrosis)
What is an Allele?
one of several alternative forms of a gene at a specific locus
What is Autozygosity?
Homozygous by inheritance - person has inherited the same mutant allele through two branches of the same family.
What is Compound Heterozygosity?
where there are 2 different mutations on the same allele.
What is Consanguinity?
the reproductive union between 2 relatives.
What is Hemizygous?
Describes a gene carried on an unpaired chromosome, such as located on the X chromosome in a male.
What is imprinting?
for some genes only 1 out of 2 is active. for particular genes it’s always the paternal or maternal. (prader-willi syndrome and Angelmans)
What is locus Heterogeneity?
mutations in a different gene causing the same clinical condition.
What is Lyonisation?
The process of X chromosome inactivation. is a random process, the paternal or maternal X could be turned off - can be skewed. Prevents females having twice as many X products as men)
What is mosaicism?
a population of mutated cells that aren’t found in your normal germline DNA.
