Patho Chapter 6- Genetics+ developmental disorders

What are the components of the genetic system

DNA, RNA, genes, chromosomes

Do chromosomes have identical sides

Yes, one from mom and one from dad

What is genetic code

Genes on a specific chromosome that have info for the protein production

What forms a codon

3 DNA bases

What is the function of a codon

Is transcribed and translated by RNA to produce single amino acids

What is the function of UAA, UAG, and UGA

Signals to stop making protein

Function of AUG

Signals part of protein synthesis

tRNA

Transport RNA

What are chromosomes

Double stranded DNA in cell nucleus

What are autosomes

non-sex chromosomes (22 pair)

Can genes hop back and forth in a chromosome

Yes

What do histones determine

They determine if you express a gene or not

What do histones do

They unzip to reveal DNA to make a copy

Epigenetics

Determine if a gene is silenced or not

What can your diet do to your genes

Change them or how they are expressed

Mitotic cell division

Somatic cell division that results in 2 cells identical to original cell

Each cell contains 23 pairs of chromosomes

Meotic cell division

Gamete cell division, results in 2 cells each with 23 SINGLE chromosomes

Genotype

The genetics

Phenotype

The genetics expressed

What is deletion

loss of a chromosome segment

What is duplication

repeats a segment

What is inversion

Gene is flipped

Insertion

A mutation involving the addition of one or more nucleotide pairs to a gene.

translocation

a chromosome abnormality caused by rearrangement of parts between nonhomologous chromosomes

What are homozygous alleles?

Mom+dad's alleles are the same

Heterozygous alleles

two different alleles

what is an allele

a gene (one from mom one from dad)

To avoid disease, you only need one good side of a chromosome T or F

T

Where does mitochondrial disease come from

Mom's side

Autosomal dominant

mutation is on autosome, inheriting one results in expression

Autosomal recessive

mutation on autosome, inheriting both results in expression

sex linked

mutation on sex chromie, linked to X, males more likely to be effected

Polygenic disorders

Multiple alleles at different chromosome locations affect phenotypes

What can be detected by karyotype

Number and visual appearance of chromosomes in the cell nuclei

Non disjunction

Failure of sister chromatids to separate during cell division

Mosaicism

Two or more population of cells within one area of body

What can cause congenital disorders

Environment, organogenesis, teratogens, maternal infection, ionizing radiation, maternal nutrition

What disorder can develop at 2-5 wks

CNS

What disorder can develop at 2.5-5.5 wks

Heart

What disorder can develop at 3-7 wks

Extremities

What disorder can develop at 3-7.5 wks

Eyes

What disorder can develop at 6.25-12 wks

external genitalia

Sickle cell disease etiology

Single gene mutation with autosomal recessive inheritance

Sickle cell patho

Point mutation leads to altered structure of beta chain of hemoglobin, causes sickle shaped hemoglobin (HbS)

CMs of Sickle Cell disease

Jaundice, anemia, pain, organ damage

DC of Sickle Cell

Genetic screening

Lab analysis

Treatment of Sickle Cell

Avoid extreme temps, prevention of infection

MELAS Patho

Gene mutation in mitochondrial DNA, errors at transcription lead to impaired energy production

MELAS CMs

Seizures

Lactic Acidosis

Stroke-like episodes

MELAS DC

History and physical

Lab studies

Muscle biopsy

MELAS treatment

Symptom specification

Pharmacologic (anti-seizure, energy boosters)

Cochlear implants

Down syndrome patho

Alteration of autosome 21, is the result of inherited translocation

Causes developmental delays

Down syndrome CM

Mental delay, facial features

Down Syndrome DC

Prenatal diagnosis

Down syndrome treatment

Promoting max. independence and quality of life

Speech, physical therapy

Neural tube defects patho

disorders during embryologic development- results in

Anencephaly

Incomplete closure of skull

Spina bifida

Incomplete spinal closure

Neural tube defects DC

Physical, prenatal screening

Neural tube defects treatment

Supportive care, corrective surgery