MI Unit 2 - Study Guide

What do shaded shapes mean in pedigrees?

Affected

What weeks of gestation is the first trimester?

0-13

What weeks of gestation is the second trimester?

13-26

What weeks of gestation is the third trimester?

27-40

Plasmid

Any DNA, No Cell Specificity, Doesn’t Trigger Immune Response, Doesn’t Host Cell Genome Integration, Low Efficiency

Liposome

Any DNA, No Cell Specificity, Doesn’t Trigger Immune Response, Doesn’t Host Cell Genome Integration, Low Efficiency

Herpes Virus

20,000 bp DNA, Nervous System Only, Triggers Immune Response, Doesn’t Host Cell Genome Integration, Low Efficiency

Adeno-associated Virus

5,000 bp DNA, No Cell Specificity, Doesn’t Trigger Immune Response, Hosts Cell Genome Integration, Efficient

Adenovirus

7,500 bp DNA, No Cell Specificity, Doesn’t Trigger Immune Response, Doesn’t Host Cell Genome Integration, Efficient

Retrovirus

8,000 bp DNA, Dividing Cells only, Triggers Immune Response, Hosts Cell Genome Integration, Low Efficiency

Lentivirus

8,500 bp DNA, No Cell Specificity, Doesn’t Trigger Immune Response, Hosts Cell Genome Integration, Efficient

CRISPR

An acronym for Clustered Regularly Interspaced Short Palindromic Repeats. The name refers to the short, palindromic repeated DNA sequences found in the genome of these bacteria.

Cas9

The enzyme used to cut the two strands of DNA.

Steps of In-vitro Fertilization

1. Egg production stimulated by hormone therapy

2. Eggs retrieved from ovary

3. Sperm sample provided

4. Fertilization

5. Incubation: Fertilized eggs grow and divide

6. Embryos introduced into uterus and/or frozen for future use

Duchenne Muscular Dystrophy

Single gene

Caused by mutations in non chromosomal DNA passed from mother to child

Cystic Fibrosis

Single gene

Results when a gene is mutated resulting in a protein product that can no longer carry out its normal job

Huntington’s Disease

Single gene

Results when a gene is mutated resulting in a protein product that can no longer carry out its normal job

Down Syndrome

Chromosomal

Arises when there are missing or extra copies of genes, or breaks, deletions or reassortment of genes

Alzheimer’s Disease

Multifactorial

Caused by a combination of environmental factors and mutations in several gene

Leber Hereditary Optic Neuropathy

Mitochondrial

Caused by mutations in non chromosomal DNA passed from mother to child

What Chromosomal disorder affects chromosome 18?

Edwards syndrome

Which trimester does cell-free fetal DNA analysis take place?

2

NT Ultrasound

1st Trimester

Nuchal Translucency Ultrasound

This image measures the thickness near the fetus’ neck, helping to assess the risk of chromosomal abnormalities.

Cell-free fetal DNA analysis

2nd Trimester

This screening assesses the risk of chromosomal abnormalities by measuring hormone & protein levels the mother's blood.

hCG, PAPP-A

1st Trimester

This test screens for chromosomal abnormalities by analyzing fetal DNA present in the mother's blood.

Amniocentesis

2nd Trimester

This invasive test performed by sampling amniotic fluid, which contains fetal cells and DNA.

Anatomy Ultrasound

2nd Trimester

This image assesses fetal anatomy, growth, and development, and to detect any structural abnormalities.

AFP, hCG, DIA, uE3 (Quad Screening)

2nd Trimester

This blood test evaluates the risk of neural tube defects and chromosomal issues by measuring levels hormones & proteins.

CVS (Chorionic Villus Sampling)

1st Trimester

This invasive procedure typically performed by sampling cells from the placenta, which contain genetic material from the fetus.

Describe Cystic Fibrosis

Autosomal Recessive

An inherited life-threatening disease that damages the lungs and digestive system.

Describe Hemophilia A

X-linked Recessive

An inherited disorder where the blood does not clot in the typical way because it doesn’t have enough blood-clotting proteins.

PGT - A

(Down Syndrome)

A treatment where embryos are screened for aneuploidy which is abnormalities in the number of chromosomes. This treatment is recommended for expecting parents with a family history of chromosomal problems.

PGT - M

(Huntington’s Disease, Cystic Fibrosis)

A recommended screening when one or both genetic parents have a known genetic abnormality, through this screening, an embryo is tested for monogenic/single gene defects to determine if it also carries genetic abnormality.

PGT - SR

(Trisomy 18/Edwards Syndrome)

Involves observing the chromosome structure of the embryos and finding where DNA segments may have been deleted, duplicated or inverted. It is recommended to people chromosome structural rearrangement, to improve the chance of a healthy pregnancy.

PGT - HLA

(Sickle Cell Disease)

Compares the mother's DNA and father's DNA to that of the affected child. The HLA typing of single or few cells are biopsied from in vitro fertilized preimplantation embryos.

What is trisomy 21?

Down syndrome

Describe Huntington’s disease

Autosomal Dominant

An inherited condition in which nerve cells in the brain break down over time that results in progressive movement, thinking (cognitive), and psychiatric symptoms.