Topic 2 - Forms of Inherited disease Flashcards
(84 cards)
What is a genetic disease?
any kind of disease that involves genes
Monogenic
inherited and caused by 1 gene
Multifactorial disease
polygenic and non-genetic (environmental)
Chromosomal disorders
genomes and chromosomes
Not all genetic diseases are
inherited
congenital/inherited =
condition present at birth
acquired/somatic =
not inherited, not present at birth
Human Genome:
- 46 chromosomes (23 pairs) - 22 autosomes - 1 sex chromosome - 20,000 genes across the bases - haploid genome - 3 billion bp of DNA packaged into chromosomes
Haploid
containing 1 copy of each chromosomes
Diploid
containing 2 copies of each chromosomes
Genome
entire genetic information of an individual
Locus (plural: loci) =
position on chromosome
Allele =
alternative forms of gene/locus/variant
Homozygous =
two copies of same allele at same locus (genotype AA or BB)
Heterozygous =
different alleles at same locus (genotype AB or BA)
Mutation –
disease causing allele
polymorphism
alleles present in >1% of population
variant
encompasses al loci where there are multiple alleles in human population regardless of commonness or pathogenicity.
Simple modes of inheritance
Single gene characteristics and traits are inherited in a predictable way (Mendelian/monogenic) - Autosomal dominant - Autosomal recessive - X-linked
Monogenic
single gene controlling specific disease
autosomal -
carried on an autosome (ch 1-22)
X linked
carried on X chromosome
Dominant
trait present when only 1 mutant allele is present
Recessive
trait present when both alleles of gene are mutated























