Patterns Of Inheritance and Mitochondria

Question 1

All generations affected
male and female offspring affected at same rate
can be inherited from M/D
Can express ________ dominance
(Homozygote BB are more _____ than heterozygotes)

Answer 1

Autosomal Dominant
(Incomplete;
SEVERE)

Question 2

Few generations are affected
male and female children affected at same rate
Parents can be ________ carriers with no symptoms.
(Only _________ are affected)

Answer 2

Autosomal Recessive
(Unaffected;
Homozygotes)

Question 3

Father to ______ transmission
FEMALES MOST affected than males
Males have a HIGH LETHALITY with the disease
Present in many generations

Answer 3

X-Linked Dominant

Daughter

Question 4

Father to ______ and mother to ______ transmission
MORE MALES are affected than females if mother’s a carrier.
Not always expressed in parents nor in all generations
No male to male transmission

Answer 4

X-Linked Recessive

Daughter; son

Question 5

All children of __________ mother are affected.
Males and female offspring affected at the same rate.
Range in severity of phenotype; variable expressively

Answer 5

Mitochondrial Inheritance

Question 6

Different mutations at the SAME GENE (LOCUS) lead to SAME PHENOTYPE
Example disease and pathogenesis:_______________

Answer 6

Allelic heterogeneity

Cystic Fibrosis - defective mRNA translation, receptor or transport

Question 7

MUTATIONS IN MULTIPLE GENES manifest as a SINGLE PHENOTYPE

Ex:_____

Answer 7

Locus Heterogeneity

Long QT Phenotype - mutated K+,Na+ and ankyrin channels which are coded by many different genes

Question 8

SINGLE GENE MUTATION leads to MULTIPLE PHENOTYPES
Vastly different organ systems affected
Ex:______

Answer 8

Pleiotropy

Ex: Mitochondrial Disease symptoms (Leigh Syndrome and LHON) or VHL Disease (from a defective pVHL in HIF1 pathway)

Question 9

This is term is used to describe an abnormal gene on an x-chromosome of a ________ patient.

Answer 9

Hemizygosity;

Male

Question 10

An individual expresses this when both alleles are MUTANT but are located at DIFFERENT LOCI in 1 GENE. In other words, the type of mutation in each allele can be different. This is a possible feature of __________ ____________ inheritance.

Answer 10

Compound heterozygosity

Autosomal recessive

Question 11

Process of methylation (silencing) genes to
Dependent on sex of transmitting parent
Mom’s is methylated
Dad’s is expressed

Answer 11

Genomic Imprinting

Question 12

Genes are present on autosomes
Mutations are carried both sexes
phenotype is expressed in ONLY 1 SEX
Ex:_____

Answer 12

Sex-Limited Autosomal

(Male-limited precocious puberty) - A.D
(Hemochromatosis) - A.R.

Question 13

What mitochondrial disorders do not manifest with “red ragged fibers”? Describe the symptoms of each.

Answer 13

Leigh Syndrome (LS) - severe neurometabolic disorder affecting the CNS
Leber Hereditary Optic Neuropathy (LHON) - loss of central vision due to degeneration of retinal ganglion cells

Question 14

Mitochondrial Bottleneck Effect

Answer 14

The initial tapering off and reset of heteroplasmy in mitochondrial DNA.

Question 15

Define Heteroplasmy

Answer 15

A mixture of normal and mutated mitochondria; relates to phenotype of diseases and a low threshold effect for HIGH ENERGY tissues such as cardiac and skeletal muscle.

Question 16

DNA Polymerase ______ initiates replication for mitochondria. _________ is a binding protein that holds mtDNA apart for synthesis. Twinkle is a mitochondrial ______________.
_________ is a transcriptional activator that can cover the plasmid of oxidative damage.

Answer 16

Gamma (y);
MtSSB;
Helicase;
TFAM

Question 17

Most mitochondrial diseases (except LS and LHON) express this microscopic feature, ___________. They also happen to have a ___________effect involving many organs systems. Overall cells _________ using O2 are ____________ affected.

Answer 17

“Red Ragged Fibers”;
Pleiotropic;
Actively; MOST
(*Grandmother, mother and daughter can express different organ diseases, BUT they all relate to mitochondria).

Question 18

True homozygosity

Answer 18

Expressed in autosomal recessive inheritance. For instance, both parents (in a pedigree) may have married consanguineously, showing that the diseased allele is on the same gene because both parents were unaffected carriers.