mandeline genetics Flashcards
(28 cards)
certain regions on dna consists of sequence that recognise the info for making info —– , —— transcribed the info into mrna molecule for translation into a protein at the ribosomes
- gene recognised by transcription factors
- rna polymerase
true or false:
pedigree analysis include -
- autosomal dominant
- autosomal recessive
- y linked
- x linked recessive
- x linked dominant
true
most autosomal dominant inheritance is expressed in —- and they die before —- v late onset disease
- heterogeneous
- maturity
—– in autosmal dominant at selective disadvantage and they die before —–
- homogenous
- reproductive maturity
AD allele frequencies are usually —
low
- familial gyoercholestrole
- polycystic kidney disease
-neurofibromatosis - familial adenomatous polyposis (FAP )
are all examples of —-
AD
most common AD mating is :
affected and normal parents
apparent exceptions to the AD pattern :
—– refers to sporadic cause may arise within families by de-nevo mutation
mutation
apparent exceptions to the AD pattern :
—– refers to the nature and severity of the phenotype but everyone w the genotype show it
variable expressivity
apparent exceptions to the AD pattern :
—- refers to the proportion of individuals with a given genotype who show the associated phenotype
reduced penetrance
mutation types are:
1- deletion or insertion which leads to —–
2- single base subsitutions as:
- frameshift mutation which leads to disruption in code
- polymorphism , missense , nonsense , mutation position ?
—- refers to the synonyous mutation as: CCA or CCC both code for proline
polymorphism
—- non-synonymous by which one amino acid is replaced by another as : UUC —> UUA
missesne mutation
—- an amino acid codon becomes a stop codon
nonsense mutation
—- creates or destroy an exon-intern splicing signal which can be done by all of the above mentioned mutations
splice-site
—- coding region of a gene = functional significance promoter/regualtory elements which alters expression
mutation position
to name the mutation:
example:
R408W refers to
R: codon
408: position
W: what it replaces
how does mutation at a single gene cause a disease phenotype?
1- haplosuffiency: where normal physiological requires more than 50% of the gene product as structural protein, Ts , receptors and enzymes , no margin safety loss of 50% of normal activity of protein = disease
2- dominant -ve effect: abnormal protein produced interferes w the function of the product of a normal allele
3- gain function: function of mutant protein is enhanced aa: achondroplasia and huntigtons disease
4- loss of hentrogenity: dominantly inherited cancers , inherited copy of mutant gene and random loss of normal allele , even in only few cells render those cells cancerous
yes or no :
in heterogeneous , is the product from the one normal allele sufficient to carry our the function of the gene
no in AD
in autosomal recessive storms are seen only in —–
homogenous recessive ( 2 mutant alleles no normal ones )
true or false:
in AR inheritance the carriers are selective disadvatahe even if the affected indivuials don’t breed the mutation can be widespread
false , not in a selective disadvantage
AR diseases are —- common that AD
more
the most common type of mating in AR is:
- unaffected carrier father and unaffected carrier mother by which the 2 carriers mate and produce :
1 in 2 carrier
1 in 4 unaffected child
1 in 4 normal child
identifying AR diseases
( read through them not important much )
1- newborn screening programmes
2- mutable affected siblings within large sib ships
3- parental consanguinity
4- demonstration of partial defect in obligate hetrogenous as structural qauantitve
