L39 Mendelian Inheritance Autosomal vs Recessive Disorders Flashcards
mandolin inheritance?
inheritance of treats that are controlled by 1 gene with 2 alleles
what is a pedigree and its characteristics?
it’s a chart representation of an individual ancestry and relatedness of a family.
1) shows relationships and identifies individuals with a certain trait.
2) shows how a trait is passed down from generation to generation
3) it determines the mode of inheritance whether the trait is autosomal dominant/recessive or sex linked.
4) accurate risk calculations for family members
what is a punette square?
its a chart that allows determination of expectations of possible genotypes of the offspring.
autosomal dominant inheritance?
1) affect both males and females equally
2) all forms of transmissions between sex is observed
3) affected people are usually to at least 1 affected parent
4) the pedigree usually shows vertical transmission of trait through generations
5) usually involves genes encoding regulatory proteins of complex pathways or key structural proteins
6) affected children are usually heterozygous
the phenotype of autosomal dominant inheritance appears in almost every generation each affected person have an affected parent except?
1) case originating form fresh mutation of gametes of phenotypically normal parents
2) case in which the disorder is not expressed (non-panetrant)
3) cases I which the disorder shows genetic variation on the clinical phenotype among generation of the same family———->polycystic kidney
what are the genetic risks of autosomal dominant inheritance?
a child to an affected parent has 50% chance to be affected as well
nervous system: neurofibromatosis
hematology: hereditary spherocytosis
autosomal recessive inheritance?
both alleles must be abnormal or mutant for the recessive trait to be expressed , the unaffected parent of an affected child is an obligate heterozygous carrier for the recessive mutant allele.
autosomal recessive inheritance characteristics?
1) males and females are equally likely to be affected
2) transmitted by either sex
3) affected kids are normally to unaffected parents
4) more commonly observed in consiguency matings
5) the pedigree usually shows horizontal transmission of trait with multiple members of the same generation.
6) usually involves genes of enzymes and proteins
7) affected children may be homozygous for specific mutant allele or can be heterozygous of 2 mutations
genetic risk of autosomal recessive inheritance?
couples who are both heterozygous have a 25% chance of producing an affected child and 2/3 kid will be a carrier for mutant allele
metabolic disorders: cystic fibrosis, phenylketonuria and lysosomal storage disorder
hematology: sickle cell anemia and thalassemia