Which type of genetic condition is Cri-Du-Chat syndrome?

Cri-du-chat results from deletion error in the chromosome. 5p- specifically

Cri-Du-Chat presentation

Cri-du-chat (cat's cry) syndrome, also known as 5p- (5p minus) syndrome, is a chromosomal condition that results when a piece of chromosome 5 is missing. Infants with this condition often have a high-pitched cry that sounds like that of a cat. The disorder is characterized by intellectual disability and delayed development, small head size (microcephaly), low birth weight, and weak muscle tone (hypotonia) in infancy. Affected individuals also have distinctive facial features, including widely set eyes (hypertelorism), low-set ears, a small jaw, and a rounded face. Some children with cri-du-chat syndrome are born with a heart defect.

What type of disorders are usually associated with repeat expansions (STRs, VTRs)?

Neurological disorders. Think perseveration.

Anticipation in context of repeat expansions

anticipation is the progressive increase in genetic problems in future generations.

if grandpa died at 60, dad died at 50 and son died at 40, what might this be an example of?

anticipation in genetic problem

STR

Short tandem repeat

VTR

variable number tandem repeat

STR vs VTR

Both are repetitive sequences of DNA, usually found in the non-coding section of a gene, VTRs are longer

CNV vs STR/VTR

Copy number variants, much larger and may duplicate whole genes and genetic segments

cause of structural abnormalities in cells

mutant cell lines in the early developing embryo

paracentric mutation

dna re-inserted without the centromere

pericentric mutations

reinserted piece of dna with the centromere

isochrome mutation

mutation ending with two p-arms or two q-arms

autosomal aneuploidy

abnormalities not involving the sex chromosomes

Trisomy 21

Chromosomes 1-22 are autosomal
Chromosome 23 is

sex chromosome

Chromosome 23 is the sex chromosome
Chromosomes 1-22 are

autosomal

Examples of conditions from sex chromosome aneuploidy are:

Turner syndrome (X0, missing second X chromosome)
Kleinfelter syndrome (XXY, extra X chromosome)

Turner syndrome

Klinefelter syndrome

Polyploidy

More than two paired sets of chromosomes

Example of polyploidy

Triploidy, involves 69 chromosomes, leads to abortion

Nondisjunction

Refers to the failrue of homologous chromosomes to separate properly during cell division

When can nondisjunction happen?

During meiosis I or II separation does not happen properly and the gamete has abnormal chromosome numbers

Pyramidine bases

CUT

Purine bases

AG

AUG

Start codone, Methionine

UAA
UGA
UAG

You are annoying
You go away
You are gone

Stop codons

Prophase II

Spindles show up from the centrosome and get ready to pull chromosomes apart

What is the function of mRNA

This carries the transcribed copy of a protein code to the ribosome in the cytoplasm where translation can occur and proteins can be synthesized.

What are codons?

3-nucleotide sequences within the mRNA that specify for particular amino acids

3 categories of genetic/genomic diseases

Chromosomal disorders
Single gene defects
Multifactorial diseases with complex inheritance

What is the process by which mRNA is created

RNA Polymerase converts the gene into mRNA

Characteristics of the genome:
Chromosomes
Genes
DNA

Genome- all of it
chromosomes- 46 of em (23 pairs)
genes- 20-25k
DNA- sequences of nitrogenous base pairs

Prometaphase

In between prophase and metaphase
Spindle fibers that showed up attach to chromosomes

Process of transcription

RNA polymerase copies DNA in chunks

Translation

The process of translating the RNA into functional proteins

S phase of cell cycle

This is where chromosomes are synthesized, 96 chromosomes in the cell at this poiint

Codominance

AB blood type, both are dominant so you get both
Also, spotted cow

Incomplete dominance

Red flower + white flower = pink flower

rRNA's role is

rRNA is a non-coding RNA which is the primary component of the ribosome and carries out protein synthesis in ribosomes.

G0 phase

Cell is resting, 0 growth at this phase = G0

Telophase

Chromosomes make it to the opposite end,
new nucleus forms around the chromosomes
actin fibers pinch the middle and start to divide the cell

tRNA

Link that carries 3 nucleotides to the ribosome for protein synthesis

Anaphase

Fibers shorten and pull the sister chromatids apart, to the opposite end of the cell

Regulatory sequence in DNA

Site of the binding of regulatory proteins that allow for more or less expression of genes

FISH (Fluorescense In-Situ Hybridization) tests

chromosomes

Predisposition genetic testing

Testing for asymptomatic people who are at <100% risk of genetic problem

Presymptomatic testing

Testing of asymptomatic people who are at 100% risk of genetic problem (Huntingtons that hasnt begun yet)

Diagnosis and prognosis of leukemia. What are you testing?

Philadephia chromosome - translocation (trading of section) of chromosomes 9 and 12

Genomic defects: BRCA 1/2

Potential to cause hereditary breast and ovarian cancer

X linked inheritance with an affected mother and unaffected father

50/50 affected, because it is dominant, no carrier. You either get it or you dont.

Carrier mother - O
Unaffected father (square)
2 unaffected, 1 carrier daughter, 1 affected son

X linked recessive

Unaffected father
Affected mother
2 affected sons, 2 carrier daughters

X linked recessive

Females can be carriers but men cannot
Abnormal allele occurs in equal frequency in males and females
Males always exhibit trait are are more commonly affected
Females require both abnormal alleles

X linked recessive

Hemophilia A
Duchennes muscular dystrophy
Red-green color blindness

X- recessive

Affected father, unaffected mother
2 unaffected sons, 2 carrier daughters

X recessive

Y linked inheritance

Only males are affected
Affected males pass to all sons
Females are not affected and not carriers
Females do not pass on

When using methylation for genetic testing, what are you testing?

Epigenetics

DNA sequencing is also called

Next generation sequencing

Autosomal dominant example

Huntington

hunters are dominant as fuck

Autosomal recessive examples

taysachs

cystic fibrosis

Autosomal recessive affected parents

Will always have affected offspring

Carriers only apply to:

Recessive